ErrorProvider.SetError メソッドとは何？わかりやすく解説 Weblio辞書

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.NET Framework クラスライブラリリファレンス

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ErrorProvider.SetError メソッド

指定したコントロールに対し、エラーを説明する文字列を設定します。

名前空間: System.Windows.Forms
アセンブリ: System.Windows.Forms (system.windows.forms.dll 内)
構文

Visual Basic (宣言)

Public Sub SetError ( _
    control As Control, _
    value As String _
)

Visual Basic (使用法)

Dim instance As ErrorProvider
Dim control As Control
Dim value As String

instance.SetError(control, value)

public void SetError (
    Control control,
    string value
)

C++

public:
void SetError (
    Control^ control, 
    String^ value
)

public void SetError (
    Control control, 
    String value
)

JScript

public function SetError (
    control : Control, 
    value : String
)

パラメータ

control: エラーを説明する文字列を設定する対象となるコントロール。

value: エラーを説明する文字列。

例外

例外の種類	条件
ArgumentNullException	control が null 参照 (Visual Basic では Nothing) です。

解説

文字列の長さが 0 以上の場合は、エラーアイコンが表示され、エラーアイコンのツールヒントの部分はエラーを説明するテキストになります。文字列の長さが 0 の場合、エラーアイコンは非表示になります。

使用例

ErrorProvider クラスを使用して、データ入力エラーをユーザーに通知する方法を次のコード例に示します。TextBox コントロール、NumericUpDown コントロール、および ComboBox コントロールが配置された Form を作成する例を次に示します。内容の検証は各コントロールで実行し、各コントロールの ErrorProvider も作成します。BlinkRate プロパティと BlinkStyle プロパティ、および SetIconAlignment メソッドと SetIconPadding メソッドを使用してエラーアイコンのオプションを設定する例を次に示します。SetError メソッドは、コントロールの内容に応じて、コントロールの Validated イベント時に、適切なエラーテキスト付きまたはエラーテキストなしで呼び出されます。

Visual Basic

Imports System
Imports System.Drawing
Imports System.Windows.Forms

Namespace ErrorProvider

    Public NotInheritable Class
 Form1
        Inherits System.Windows.Forms.Form
    
        Private label1 As System.Windows.Forms.Label
        Private label2 As System.Windows.Forms.Label
        Private label3 As System.Windows.Forms.Label
      
        Private label4 As System.Windows.Forms.Label
        Private label5 As System.Windows.Forms.Label
        Private label6 As System.Windows.Forms.Label
        Friend WithEvents favoriteColorComboBox
 As System.Windows.Forms.ComboBox 
        Friend WithEvents nameTextBox1 As
 System.Windows.Forms.TextBox 
        Friend WithEvents ageUpDownPicker As
 System.Windows.Forms.NumericUpDown      
        Private ageErrorProvider As System.Windows.Forms.ErrorProvider
 
        Private nameErrorProvider As System.Windows.Forms.ErrorProvider
 
        Private favoriteColorErrorProvider As
 System.Windows.Forms.ErrorProvider
        
        <System.STAThread()>  _
        Public Shared Sub
 Main()
            System.Windows.Forms.Application.Run(New Form1())
        End Sub 'Main

        Public Sub New()
            
            Me.nameTextBox1 = New System.Windows.Forms.TextBox()
            Me.label1 = New System.Windows.Forms.Label()
            Me.label2 = New System.Windows.Forms.Label()
            Me.ageUpDownPicker = New System.Windows.Forms.NumericUpDown()
            Me.favoriteColorComboBox = New
 System.Windows.Forms.ComboBox()
            Me.label3 = New System.Windows.Forms.Label()
            Me.label4 = New System.Windows.Forms.Label()
            Me.label5 = New System.Windows.Forms.Label()
            Me.label6 = New System.Windows.Forms.Label()

            ' Name Label
            Me.label1.Location = New System.Drawing.Point(56,
 32)
            Me.label1.Size = New System.Drawing.Size(40,
 23)
            Me.label1.Text = "Name:"

            ' Age Label
            Me.label2.Location = New System.Drawing.Point(40,
 64)
            Me.label2.Size = New System.Drawing.Size(56,
 23)
            Me.label2.Text = "Age (3-5)"

            ' Favorite Color Label
            Me.label3.Location = New System.Drawing.Point(24,
 96)
            Me.label3.Size = New System.Drawing.Size(80,
 24)
            Me.label3.Text = "Favorite color"

            ' ErrorBlinkStyle.AlwaysBlink Label
            Me.label4.Location = New System.Drawing.Point(264,
 32)
            Me.label4.Size = New System.Drawing.Size(160,
 23)
            Me.label4.Text = "ErrorBlinkStyle.AlwaysBlink"

            ' ErrorBlinkStyle.BlinkIfDifferentError Label
            Me.label5.Location = New System.Drawing.Point(264,
 64)
            Me.label5.Size = New System.Drawing.Size(200,
 23)
            Me.label5.Text = "ErrorBlinkStyle.BlinkIfDifferentError"

            ' ErrorBlinkStyle.NeverBlink Label
            Me.label6.Location = New System.Drawing.Point(264,
 96)
            Me.label6.Size = New System.Drawing.Size(200,
 23)
            Me.label6.Text = "ErrorBlinkStyle.NeverBlink"

            ' Name TextBox
            Me.nameTextBox1.Location = New
 System.Drawing.Point(112, 32)
            Me.nameTextBox1.Size = New System.Drawing.Size(120,
 20)
            Me.nameTextBox1.TabIndex = 0

            ' Age NumericUpDown
            Me.ageUpDownPicker.Location = New
 System.Drawing.Point(112, 64)
            Me.ageUpDownPicker.Maximum = New
 System.Decimal(New Integer() {150, 0, 0,
 0})
            Me.ageUpDownPicker.TabIndex = 4

            ' Favorite Color ComboBox
            Me.favoriteColorComboBox.Items.AddRange(New
 Object() {"None", "Red",
 "Yellow", _
                                                                                
    "Green", "Blue",
 "Purple"})
            Me.favoriteColorComboBox.Location = New
 System.Drawing.Point(112, 96)
            Me.favoriteColorComboBox.Size = New
 System.Drawing.Size(120, 21)
            Me.favoriteColorComboBox.TabIndex = 5

            ' Set up how the form should be displayed and add the controls
 to the form.
            Me.ClientSize = New System.Drawing.Size(464,
 150)
            Me.Controls.AddRange(New System.Windows.Forms.Control()
 {Me.label6, Me.label5, Me.label4, _
                                          Me.label3, Me.favoriteColorComboBox,
 Me.ageUpDownPicker, Me.label2, _
                                          Me.label1, Me.nameTextBox1})

            Me.Text = "Error Provider Example"

            ' Create and set the ErrorProvider for each data entry control.
     
            nameErrorProvider = New System.Windows.Forms.ErrorProvider()
            nameErrorProvider.SetIconAlignment(Me.nameTextBox1,
 ErrorIconAlignment.MiddleRight)
            nameErrorProvider.SetIconPadding(Me.nameTextBox1,
 2)
            nameErrorProvider.BlinkRate = 1000
            nameErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.AlwaysBlink
            
            ageErrorProvider = New System.Windows.Forms.ErrorProvider()
            ageErrorProvider.SetIconAlignment(Me.ageUpDownPicker,
 ErrorIconAlignment.MiddleRight)
            ageErrorProvider.SetIconPadding(Me.ageUpDownPicker,
 2)
            ageErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.BlinkIfDifferentError
            
            favoriteColorErrorProvider = New System.Windows.Forms.ErrorProvider()
            favoriteColorErrorProvider.SetIconAlignment(Me.favoriteColorComboBox,
 ErrorIconAlignment.MiddleRight)
            favoriteColorErrorProvider.SetIconPadding(Me.favoriteColorComboBox,
 2)
            favoriteColorErrorProvider.BlinkRate = 1000
            favoriteColorErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.NeverBlink
        End Sub 'New
 
        Private Sub nameTextBox1_Validated(sender
 As Object, e As System.EventArgs)
 Handles nameTextBox1.Validated
            If IsNameValid() Then
                ' Clear the error, if any, in the error provider.
                nameErrorProvider.SetError(Me.nameTextBox1, "")
            Else
                ' Set the error if the name is not valid.
                nameErrorProvider.SetError(Me.nameTextBox1, "Name
 is required.")
            End If 
        End Sub 
              
        Private Sub ageUpDownPicker_Validated(sender
 As Object, e As System.EventArgs)
 Handles ageUpDownPicker.Validated
            If IsAgeTooYoung() Then
                ' Set the error if the age is too young.
                ageErrorProvider.SetError(Me.ageUpDownPicker,
 "Age not old enough")
            ElseIf IsAgeTooOld() Then
                ' Set the error if the age is too old.
                ageErrorProvider.SetError(Me.ageUpDownPicker,
 "Age is too old")
            Else
                ' Clear the error, if any, in the error provider.
                ageErrorProvider.SetError(Me.ageUpDownPicker,
 "")
            End If
        End Sub
         
        Private Sub favoriteColorComboBox_Validated(sender
 As Object, e As System.EventArgs)
 Handles favoriteColorComboBox.Validated
            If Not IsColorValid() Then
                ' Set the error if the favorite color is not valid.
                favoriteColorErrorProvider.SetError(Me.favoriteColorComboBox,
 "Must select a color.")            
            Else
                ' Clear the error, if any, in the error provider.
                favoriteColorErrorProvider.SetError(Me.favoriteColorComboBox,
 "")
            End If
        End Sub 

        ' Functions to verify data.
        Private Function IsNameValid() As
 Boolean
            ' Determine whether the text box contains a zero-length
 string.
            Return nameTextBox1.Text.Length > 0
        End Function 

        Private Function IsAgeTooYoung() As
 Boolean
            ' Determine whether the age value is less than three.
            Return ageUpDownPicker.Value < 3
        End Function 
        
        
        Private Function IsAgeTooOld() As
 Boolean
            ' Determine whether the age value is greater than five.
            Return ageUpDownPicker.Value > 5
        End Function 
                
        Private Function IsColorValid() As
 Boolean
            ' Determine whether the favorite color has a valid value.
            If Not (favoriteColorComboBox.SelectedItem
 Is Nothing) Then
                    If Not(favoriteColorComboBox.SelectedItem.ToString().Equals("None"))
 Then
                        Return true 
                    End If
            End If
            Return false
        End Function 

    End Class 'Form1
End Namespace 'ErrorProvider

using System;
using System.Drawing;
using System.Windows.Forms;

namespace ErrorProvider
{
    public class Form1 : System.Windows.Forms.Form
    {
        private System.Windows.Forms.Label label1;
        private System.Windows.Forms.Label label2;
        private System.Windows.Forms.Label label4;
        private System.Windows.Forms.Label label5;
        private System.Windows.Forms.Label label6;
        private System.Windows.Forms.Label label3;
        private System.Windows.Forms.TextBox nameTextBox1;
        private System.Windows.Forms.NumericUpDown ageUpDownPicker;
        private System.Windows.Forms.ComboBox favoriteColorComboBox;
        private System.Windows.Forms.ErrorProvider ageErrorProvider;
        private System.Windows.Forms.ErrorProvider nameErrorProvider;
        private System.Windows.Forms.ErrorProvider favoriteColorErrorProvider;

        [STAThread]
        static void Main() 
        {
            Application.Run(new Form1());
        }

        public Form1()
        {
            this.nameTextBox1 = new System.Windows.Forms.TextBox();
            this.label1 = new System.Windows.Forms.Label();
            this.label2 = new System.Windows.Forms.Label();
            this.ageUpDownPicker = new System.Windows.Forms.NumericUpDown();
            this.favoriteColorComboBox = new
 System.Windows.Forms.ComboBox();
            this.label3 = new System.Windows.Forms.Label();
            this.label4 = new System.Windows.Forms.Label();
            this.label5 = new System.Windows.Forms.Label();
            this.label6 = new System.Windows.Forms.Label();

            // Name Label
            this.label1.Location = new System.Drawing.Point(56,
 32);
            this.label1.Size = new System.Drawing.Size(40,
 23);
            this.label1.Text = "Name:";

            // Age Label
            this.label2.Location = new System.Drawing.Point(40,
 64);
            this.label2.Size = new System.Drawing.Size(56,
 23);
            this.label2.Text = "Age (3-5)";        
   

            // Favorite Color Label
            this.label3.Location = new System.Drawing.Point(24,
 96);
            this.label3.Size = new System.Drawing.Size(80,
 24);
            this.label3.Text = "Favorite color";

            // ErrorBlinkStyle.AlwaysBlink Label
            this.label4.Location = new System.Drawing.Point(264,
 32);
            this.label4.Size = new System.Drawing.Size(160,
 23);
            this.label4.Text = "ErrorBlinkStyle.AlwaysBlink";

            // ErrorBlinkStyle.BlinkIfDifferentError Label
            this.label5.Location = new System.Drawing.Point(264,
 64);
            this.label5.Size = new System.Drawing.Size(200,
 23);
            this.label5.Text = "ErrorBlinkStyle.BlinkIfDifferentError";

            // ErrorBlinkStyle.NeverBlink Label
            this.label6.Location = new System.Drawing.Point(264,
 96);
            this.label6.Size = new System.Drawing.Size(200,
 23);
            this.label6.Text = "ErrorBlinkStyle.NeverBlink";

            // Name TextBox
            this.nameTextBox1.Location = new
 System.Drawing.Point(112, 32);
            this.nameTextBox1.Size = new System.Drawing.Size(120,
 20);
            this.nameTextBox1.TabIndex = 0;
            this.nameTextBox1.Validated += new
 System.EventHandler(this.nameTextBox1_Validated);

            // Age NumericUpDown
            this.ageUpDownPicker.Location = new
 System.Drawing.Point(112, 64);
            this.ageUpDownPicker.Maximum = new
 System.Decimal(new int[] {150,0,0,0});
            this.ageUpDownPicker.TabIndex = 4;
            this.ageUpDownPicker.Validated += new
 System.EventHandler(this.ageUpDownPicker_Validated);

            // Favorite Color ComboBox
            this.favoriteColorComboBox.Items.AddRange(new
 object[] {"None","Red","Yellow",
                                                                    "Green"
,"Blue","Purple"});
            this.favoriteColorComboBox.Location = new
 System.Drawing.Point(112, 96);
            this.favoriteColorComboBox.Size = new
 System.Drawing.Size(120, 21);
            this.favoriteColorComboBox.TabIndex = 5;
            this.favoriteColorComboBox.Validated += new
 System.EventHandler(this.favoriteColorComboBox_Validated);

            // Set up how the form should be displayed and add the controls
 to the form.
            this.ClientSize = new System.Drawing.Size(464,
 150);
            this.Controls.AddRange(new System.Windows.Forms.Control[]
 {
                                        this.label6,this.label5
,this.label4,this.label3,
                                        this.favoriteColorComboBox
,this.ageUpDownPicker,
                                        this.label2,this.label1
,this.nameTextBox1});
            this.Text = "Error Provider Example";

            // Create and set the ErrorProvider for each data entry
 control.

            nameErrorProvider = new  System.Windows.Forms.ErrorProvider();
            nameErrorProvider.SetIconAlignment (this.nameTextBox1,
 ErrorIconAlignment.MiddleRight);
            nameErrorProvider.SetIconPadding (this.nameTextBox1,
 2);
            nameErrorProvider.BlinkRate = 1000;
            nameErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.AlwaysBlink;

            ageErrorProvider = new  System.Windows.Forms.ErrorProvider();
            ageErrorProvider.SetIconAlignment (this.ageUpDownPicker,
 ErrorIconAlignment.MiddleRight);
            ageErrorProvider.SetIconPadding (this.ageUpDownPicker,
 2);
            ageErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.BlinkIfDifferentError;

            favoriteColorErrorProvider = new  System.Windows.Forms.ErrorProvider();
            favoriteColorErrorProvider.SetIconAlignment (this.favoriteColorComboBox,
 ErrorIconAlignment.MiddleRight);
            favoriteColorErrorProvider.SetIconPadding (this.favoriteColorComboBox,
 2);
            favoriteColorErrorProvider.BlinkRate = 1000;
            favoriteColorErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.NeverBlink;
        }
    
        private void nameTextBox1_Validated(object
 sender, System.EventArgs e)
        {
            if(IsNameValid())
            {
                // Clear the error, if any, in the error provider.
                nameErrorProvider.SetError(this.nameTextBox1,
 "");
            }
            else
            {
                // Set the error if the name is not valid.
                nameErrorProvider.SetError(this.nameTextBox1,
 "Name is required.");
            }
        }

        private void ageUpDownPicker_Validated(object
 sender, System.EventArgs e)
        {
            if (IsAgeTooYoung())
            {
                // Set the error if the age is too young.
                ageErrorProvider.SetError(this.ageUpDownPicker,
 "Age not old enough");
            }
            else if (IsAgeTooOld())
            {
                // Set the error if the age is too old.
                ageErrorProvider.SetError(this.ageUpDownPicker,
 "Age is too old");
            }
            else 
            {
                // Clear the error, if any, in the error provider.
                ageErrorProvider.SetError(this.ageUpDownPicker,
 "");
            }
        }

        private void favoriteColorComboBox_Validated(object
 sender, System.EventArgs e) 
        {
            if (!IsColorValid())
            {
                // Set the error if the favorite color is not valid.
                favoriteColorErrorProvider.SetError(this.favoriteColorComboBox,
 "Must select a color.");
            }
            else
            {
                // Clear the error, if any, in the error provider.
                favoriteColorErrorProvider.SetError(this.favoriteColorComboBox,
 "");
            }
        }

        // Functions to verify data.
        private bool IsNameValid() 
        {
            // Determine whether the text box contains a zero-length
 string.
            return (nameTextBox1.Text.Length > 0);
        }

        private bool IsAgeTooYoung() 
        {
            // Determine whether the age value is less than three.
            return (ageUpDownPicker.Value < 3);
        }

        private bool IsAgeTooOld() 
        {
            // Determine whether the age value is greater than five.
            return (ageUpDownPicker.Value > 5 );
        }

        private bool IsColorValid() 
        {
            // Determine whether the favorite color has a valid value.
            return ((favoriteColorComboBox.SelectedItem != null)
 &&
                (!favoriteColorComboBox.SelectedItem.ToString().Equals("None")));
        }
    }
}

C++

#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
public ref class Form1: public
 System::Windows::Forms::Form
{
private:
   System::Windows::Forms::Label ^ label1;
   System::Windows::Forms::Label ^ label2;
   System::Windows::Forms::Label ^ label4;
   System::Windows::Forms::Label ^ label5;
   System::Windows::Forms::Label ^ label6;
   System::Windows::Forms::Label ^ label3;
   System::Windows::Forms::TextBox^ nameTextBox1;
   System::Windows::Forms::NumericUpDown^ ageUpDownPicker;
   System::Windows::Forms::ComboBox^ favoriteColorComboBox;
   System::Windows::Forms::ErrorProvider^ ageErrorProvider;
   System::Windows::Forms::ErrorProvider^ nameErrorProvider;
   System::Windows::Forms::ErrorProvider^ favoriteColorErrorProvider;

public:
   Form1()
   {
      this->nameTextBox1 = gcnew System::Windows::Forms::TextBox;
      this->label1 = gcnew System::Windows::Forms::Label;
      this->label2 = gcnew System::Windows::Forms::Label;
      this->ageUpDownPicker = gcnew System::Windows::Forms::NumericUpDown;
      this->favoriteColorComboBox = gcnew System::Windows::Forms::ComboBox;
      this->label3 = gcnew System::Windows::Forms::Label;
      this->label4 = gcnew System::Windows::Forms::Label;
      this->label5 = gcnew System::Windows::Forms::Label;
      this->label6 = gcnew System::Windows::Forms::Label;
      
      // Name Label
      this->label1->Location = System::Drawing::Point( 56,
 32 );
      this->label1->Size = System::Drawing::Size( 40, 23
 );
      this->label1->Text = "Name:";
      
      // Age Label
      this->label2->Location = System::Drawing::Point( 40,
 64 );
      this->label2->Size = System::Drawing::Size( 56, 23
 );
      this->label2->Text = "Age (3-5)";
      
      // Favorite Color Label
      this->label3->Location = System::Drawing::Point( 24,
 96 );
      this->label3->Size = System::Drawing::Size( 80, 24
 );
      this->label3->Text = "Favorite color";
      
      // ErrorBlinkStyle::AlwaysBlink Label
      this->label4->Location = System::Drawing::Point( 264,
 32 );
      this->label4->Size = System::Drawing::Size( 160, 23
 );
      this->label4->Text = "ErrorBlinkStyle::AlwaysBlink";
      
      // ErrorBlinkStyle::BlinkIfDifferentError Label
      this->label5->Location = System::Drawing::Point( 264,
 64 );
      this->label5->Size = System::Drawing::Size( 200, 23
 );
      this->label5->Text = "ErrorBlinkStyle::BlinkIfDifferentError";
      
      // ErrorBlinkStyle::NeverBlink Label
      this->label6->Location = System::Drawing::Point( 264,
 96 );
      this->label6->Size = System::Drawing::Size( 200, 23
 );
      this->label6->Text = "ErrorBlinkStyle::NeverBlink";
      
      // Name TextBox
      this->nameTextBox1->Location = System::Drawing::Point(
 112, 32 );
      this->nameTextBox1->Size = System::Drawing::Size(
 120, 20 );
      this->nameTextBox1->TabIndex = 0;
      this->nameTextBox1->Validated += gcnew System::EventHandler(
 this, &Form1::nameTextBox1_Validated );
      
      // Age NumericUpDown
      this->ageUpDownPicker->Location = System::Drawing::Point(
 112, 64 );
      array<int>^temp0 = {150,0,0,0};
      this->ageUpDownPicker->Maximum = System::Decimal(
 temp0 );
      this->ageUpDownPicker->TabIndex = 4;
      this->ageUpDownPicker->Validated += gcnew System::EventHandler(
 this, &Form1::ageUpDownPicker_Validated );
      
      // Favorite Color ComboBox
      array<Object^>^temp1 = {"None","Red","Yellow"
,"Green","Blue","Purple"};
      this->favoriteColorComboBox->Items->AddRange( temp1
 );
      this->favoriteColorComboBox->Location = System::Drawing::Point(
 112, 96 );
      this->favoriteColorComboBox->Size = System::Drawing::Size(
 120, 21 );
      this->favoriteColorComboBox->TabIndex = 5;
      this->favoriteColorComboBox->Validated += gcnew System::EventHandler(
 this, &Form1::favoriteColorComboBox_Validated );
      
      // Set up how the form should be displayed and add the controls
 to the form.
      this->ClientSize = System::Drawing::Size( 464, 150 );
      array<System::Windows::Forms::Control^>^temp2 = {this->label6
,this->label5,this->label4,this->label3
,this->favoriteColorComboBox,this->ageUpDownPicker,this->label2,this->label1,this->nameTextBox1};
      this->Controls->AddRange( temp2 );
      this->Text = "Error Provider Example";
      
      // Create and set the ErrorProvider for each data entry control.
      nameErrorProvider = gcnew System::Windows::Forms::ErrorProvider;
      nameErrorProvider->SetIconAlignment( this->nameTextBox1,
 ErrorIconAlignment::MiddleRight );
      nameErrorProvider->SetIconPadding( this->nameTextBox1,
 2 );
      nameErrorProvider->BlinkRate = 1000;
      nameErrorProvider->BlinkStyle = System::Windows::Forms::ErrorBlinkStyle::AlwaysBlink;
      ageErrorProvider = gcnew System::Windows::Forms::ErrorProvider;
      ageErrorProvider->SetIconAlignment( this->ageUpDownPicker,
 ErrorIconAlignment::MiddleRight );
      ageErrorProvider->SetIconPadding( this->ageUpDownPicker,
 2 );
      ageErrorProvider->BlinkStyle = System::Windows::Forms::ErrorBlinkStyle::BlinkIfDifferentError;
      favoriteColorErrorProvider = gcnew System::Windows::Forms::ErrorProvider;
      favoriteColorErrorProvider->SetIconAlignment( this->favoriteColorComboBox,
 ErrorIconAlignment::MiddleRight );
      favoriteColorErrorProvider->SetIconPadding( this->favoriteColorComboBox,
 2 );
      favoriteColorErrorProvider->BlinkRate = 1000;
      favoriteColorErrorProvider->BlinkStyle = System::Windows::Forms::ErrorBlinkStyle::NeverBlink;
   }


private:

   void nameTextBox1_Validated( Object^ /*sender*/, System::EventArgs^
 /*e*/ )
   {
      if ( IsNameValid() )
      {
         
         // Clear the error, if any, in the error provider.
         nameErrorProvider->SetError( this->nameTextBox1,
 "" );
      }
      else
      {
         
         // Set the error if the name is not valid.
         nameErrorProvider->SetError( this->nameTextBox1,
 "Name is required." );
      }
   }

   void ageUpDownPicker_Validated( Object^ /*sender*/, System::EventArgs^
 /*e*/ )
   {
      if ( IsAgeTooYoung() )
      {
         
         // Set the error if the age is too young.
         ageErrorProvider->SetError( this->ageUpDownPicker,
 "Age not old enough" );
      }
      else
      if ( IsAgeTooOld() )
      {
         
         // Set the error if the age is too old.
         ageErrorProvider->SetError( this->ageUpDownPicker,
 "Age is too old" );
      }
      else
      {
         
         // Clear the error, if any, in the error provider.
         ageErrorProvider->SetError( this->ageUpDownPicker,
 "" );
      }
   }

   void favoriteColorComboBox_Validated( Object^ /*sender*/, System::EventArgs^
 /*e*/ )
   {
      if (  !IsColorValid() )
      {
         
         // Set the error if the favorite color is not valid.
         favoriteColorErrorProvider->SetError( this->favoriteColorComboBox,
 "Must select a color." );
      }
      else
      {
         
         // Clear the error, if any, in the error provider.
         favoriteColorErrorProvider->SetError( this->favoriteColorComboBox,
 "" );
      }
   }


   // Functions to verify data.
   bool IsNameValid()
   {
      
      // Determine whether the text box contains a zero-length String*.
      return (nameTextBox1->Text->Length > 0);
   }

   bool IsAgeTooYoung()
   {
      
      // Determine whether the age value is less than three.
      return (ageUpDownPicker->Value < 3);
   }

   bool IsAgeTooOld()
   {
      
      // Determine whether the age value is greater than five.
      return (ageUpDownPicker->Value > 5);
   }

   bool IsColorValid()
   {
      
      // Determine whether the favorite color has a valid value.
      return ((favoriteColorComboBox->SelectedItem != 0) &&
 ( !favoriteColorComboBox->SelectedItem->Equals( "None" )));
   }

};


[STAThread]
int main()
{
   Application::Run( gcnew Form1 );
}

package ErrorProvider;

import System.*;
import System.Drawing.*;
import System.Windows.Forms.*;

public class Form1 extends System.Windows.Forms.Form
{
    private System.Windows.Forms.Label label1;
    private System.Windows.Forms.Label label2;
    private System.Windows.Forms.Label label4;
    private System.Windows.Forms.Label label5;
    private System.Windows.Forms.Label label6;
    private System.Windows.Forms.Label label3;
    private System.Windows.Forms.TextBox nameTextBox1;
    private System.Windows.Forms.NumericUpDown ageUpDownPicker;
    private System.Windows.Forms.ComboBox favoriteColorComboBox;
    private System.Windows.Forms.ErrorProvider ageErrorProvider;
    private System.Windows.Forms.ErrorProvider nameErrorProvider;
    private System.Windows.Forms.ErrorProvider favoriteColorErrorProvider;

    /** @attribute STAThread()
     */
    public static void main(String[]
 args)
    {
        Application.Run(new Form1());
    } //main

    public Form1()
    {
        this.nameTextBox1 = new System.Windows.Forms.TextBox();
        this.label1 = new System.Windows.Forms.Label();
        this.label2 = new System.Windows.Forms.Label();
        this.ageUpDownPicker = new System.Windows.Forms.NumericUpDown();
        this.favoriteColorComboBox = new System.Windows.Forms.ComboBox();
        this.label3 = new System.Windows.Forms.Label();
        this.label4 = new System.Windows.Forms.Label();
        this.label5 = new System.Windows.Forms.Label();
        this.label6 = new System.Windows.Forms.Label();
        // Name Label
        this.label1.set_Location(new System.Drawing.Point(56,
 32));
        this.label1.set_Size(new System.Drawing.Size(40,
 23));
        this.label1.set_Text("Name:");
        // Age Label
        this.label2.set_Location(new System.Drawing.Point(40,
 64));
        this.label2.set_Size(new System.Drawing.Size(56,
 23));
        this.label2.set_Text("Age (3-5)");
        // Favorite Color Label
        this.label3.set_Location(new System.Drawing.Point(24,
 96));
        this.label3.set_Size(new System.Drawing.Size(80,
 24));
        this.label3.set_Text("Favorite color");
        // ErrorBlinkStyle.AlwaysBlink Label
        this.label4.set_Location(new System.Drawing.Point(264,
 32));
        this.label4.set_Size(new System.Drawing.Size(160,
 23));
        this.label4.set_Text("ErrorBlinkStyle.AlwaysBlink");
        // ErrorBlinkStyle.BlinkIfDifferentError Label
        this.label5.set_Location(new System.Drawing.Point(264,
 64));
        this.label5.set_Size(new System.Drawing.Size(200,
 23));
        this.label5.set_Text("ErrorBlinkStyle.BlinkIfDifferentError");
        // ErrorBlinkStyle.NeverBlink Label
        this.label6.set_Location(new System.Drawing.Point(264,
 96));
        this.label6.set_Size(new System.Drawing.Size(200,
 23));
        this.label6.set_Text("ErrorBlinkStyle.NeverBlink");
        // Name TextBox
        this.nameTextBox1.set_Location(new
 System.Drawing.Point(112, 32));
        this.nameTextBox1.set_Size(new System.Drawing.Size(120,
 20));
        this.nameTextBox1.set_TabIndex(0);
        this.nameTextBox1.add_Validated(new
 System.EventHandler(
            this.nameTextBox1_Validated));
        // Age NumericUpDown
        this.ageUpDownPicker.set_Location(new
 System.Drawing.Point(112, 64));
        this.ageUpDownPicker.set_Maximum(new
 System.Decimal(new int[] {
            150, 0, 0, 0 }));
        this.ageUpDownPicker.set_TabIndex(4);
        this.ageUpDownPicker.add_Validated(new
 System.EventHandler(
            this.ageUpDownPicker_Validated));
        // Favorite Color ComboBox
        this.favoriteColorComboBox.get_Items().AddRange(new
 Object[] { 
            "None", "Red", "Yellow", "Green",
 "Blue", "Purple" });
        this.favoriteColorComboBox.set_Location(
            new System.Drawing.Point(112, 96));
        this.favoriteColorComboBox.set_Size(new
 System.Drawing.Size(120, 21));
        this.favoriteColorComboBox.set_TabIndex(5);
        this.favoriteColorComboBox.add_Validated(new
 System.EventHandler(
            this.favoriteColorComboBox_Validated));
        // Set up how the form should be displayed and add the controls
 to 
        // the form.
        this.set_ClientSize(new System.Drawing.Size(464,
 150));
        this.get_Controls().AddRange(new System.Windows.Forms.Control[]
 { 
            this.label6, this.label5, this.label4,
 this.label3, 
            this.favoriteColorComboBox, this.ageUpDownPicker,
 this.label2, 
            this.label1, this.nameTextBox1
 });
        this.set_Text("Error Provider Example");
        // Create and set the ErrorProvider for each data entry control.
        nameErrorProvider = new System.Windows.Forms.ErrorProvider();
        nameErrorProvider.SetIconAlignment(this.nameTextBox1,
 
            ErrorIconAlignment.MiddleRight);
        nameErrorProvider.SetIconPadding(this.nameTextBox1, 2);
        nameErrorProvider.set_BlinkRate(1000);
        nameErrorProvider.set_BlinkStyle(
            System.Windows.Forms.ErrorBlinkStyle.AlwaysBlink);
        nameErrorProvider.set_ContainerControl(this);

        ageErrorProvider = new System.Windows.Forms.ErrorProvider();
        ageErrorProvider.SetIconAlignment(this.ageUpDownPicker,
 
            ErrorIconAlignment.MiddleRight);
        ageErrorProvider.SetIconPadding(this.ageUpDownPicker,
 2);
        ageErrorProvider.set_BlinkStyle(
            System.Windows.Forms.ErrorBlinkStyle.BlinkIfDifferentError);
        ageErrorProvider.set_ContainerControl(this);

        favoriteColorErrorProvider = new System.Windows.Forms.ErrorProvider();
        favoriteColorErrorProvider.SetIconAlignment(this.favoriteColorComboBox,
 
            ErrorIconAlignment.MiddleRight);
        favoriteColorErrorProvider.SetIconPadding(this.favoriteColorComboBox,
 2);
        favoriteColorErrorProvider.set_BlinkRate(1000);
        favoriteColorErrorProvider.set_BlinkStyle(
            System.Windows.Forms.ErrorBlinkStyle.NeverBlink);
        favoriteColorErrorProvider.set_ContainerControl(this);
    } //Form1
    
    private void nameTextBox1_Validated(Object
 sender, System.EventArgs e)
    {
        if (IsNameValid()) {
            // Clear the error, if any, in the error provider.
            nameErrorProvider.SetError(this.nameTextBox1, "");
        }
        else {
            // Set the error if the name is not valid.
            nameErrorProvider.SetError(this.nameTextBox1, "Name
 is required.");
        }
    } //nameTextBox1_Validated

    private void ageUpDownPicker_Validated(Object
 sender, System.EventArgs e)
    {
        if (IsAgeTooYoung()) {
            // Set the error if the age is too young.
            ageErrorProvider.SetError(this.ageUpDownPicker, 
                "Age not old enough");
        }
        else {
            if (IsAgeTooOld()) {
                // Set the error if the age is too old.
                ageErrorProvider.SetError(this.ageUpDownPicker,
 
                    "Age is too old");
            }
            else {
                // Clear the error, if any, in the error provider.
                ageErrorProvider.SetError(this.ageUpDownPicker,
 "");
            }
        }
    } //ageUpDownPicker_Validated

    private void favoriteColorComboBox_Validated(Object
 sender, 
        System.EventArgs e)
    {
        if (!(IsColorValid())) {
            // Set the error if the favorite color is not valid.
            favoriteColorErrorProvider.SetError(this.favoriteColorComboBox,
 
                "Must select a color.");
        }
        else {
            // Clear the error, if any, in the error provider.
            favoriteColorErrorProvider.SetError(
                this.favoriteColorComboBox, "");
        }
    } //favoriteColorComboBox_Validated

    // Functions to verify data.
    private boolean IsNameValid()
    {
        // Determine whether the text box contains a zero-length string.
        return ((nameTextBox1.get_Text().get_Length()) > 0);
    } //IsNameValid

    private boolean IsAgeTooYoung()
    {
        // Determine whether the age value is less than three.
        return (System.Convert.ToInt32(ageUpDownPicker.get_Value())
 < 3);
    } //IsAgeTooYoung

    private boolean IsAgeTooOld()
    {
        // Determine whether the age value is greater than five.
        return (System.Convert.ToInt32(ageUpDownPicker.get_Value())
 > 5);
    } //IsAgeTooOld

    private boolean IsColorValid()
    {
        // Determine whether the favorite color has a valid value.
        return (favoriteColorComboBox.get_SelectedItem() != null)
 
            && (!(favoriteColorComboBox.get_SelectedItem().
            ToString().Equals("None")));
    } //IsColorValid
} //Form1

プラットフォーム

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0

参照

関連項目
ErrorProvider クラス
ErrorProvider メンバ
System.Windows.Forms 名前空間
GetError

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