Form.Load イベントとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

索引トップ用語の索引ランキング

Form.Load イベント

フォームが初めて表示される直前に発生します。

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 Event Load As EventHandler

Visual Basic (使用法)

Dim instance As Form
Dim handler As EventHandler

AddHandler instance.Load, handler

public event EventHandler Load

C++

public:
event EventHandler^ Load {
    void add (EventHandler^ value);
    void remove (EventHandler^ value);
}

/** @event */
public void add_Load (EventHandler value)

/** @event */
public void remove_Load (EventHandler value)

JScript

JScript では、イベントは使用できますが、新規に宣言することはできません。

解説

このイベントを使用して、フォームで使用されるリソースの割り当てなどを実行できます。

イベント処理の詳細については、「イベントの利用」を参照してください。

使用例

SetDesktopLocation、Load、Activated、および Activate の各メンバの使用方法を次のコード例に示します。この例を実行するには、1 つの Button コントロール (Button1) と 2 つの Label コントロール (Label1 および Label2) が配置された、Form1 という名前のフォームに、次のコードを貼り付けます。

Visual Basic

Shared x As Integer = 200
Shared y As Integer = 200

Private Sub Button1_Click(ByVal
 sender As System.Object, _
    ByVal e As System.EventArgs) Handles
 Button1.Click

    ' Create a new Form1 and set its Visible property to true.
    Dim form2 As New Form1
    form2.Visible = True

    ' Set the new form's desktop location so it appears below and 
    ' to the right of the current form.
    form2.SetDesktopLocation(x, y)
    x += 30
    y += 30

    ' Keep the current form active by calling the Activate method.
    Me.Activate()
    Me.Button1.Enabled = False
End Sub



' Updates the label text to reflect the current values of x and y, 
' which was were incremented in the Button1 control's click event.
Private Sub Form1_Activated(ByVal
 sender As Object, _
    ByVal e As System.EventArgs) Handles
 MyBase.Activated
    Label1.Text = "x: " & x & "
 y: " & y
    Label2.Text = "Number of forms currently open: "
 & count
End Sub

Shared count As Integer
 = 0

Private Sub Form1_Closed(ByVal
 sender As Object, _
    ByVal e As System.EventArgs) Handles
 MyBase.Closed
    count -= 1
End Sub

Private Sub Form1_Load(ByVal
 sender As Object, _
    ByVal e As System.EventArgs) Handles
 MyBase.Load
    count += 1
End Sub

static int x = 200;
static int y = 200;

private void Button1_Click(System.Object sender,
 
    System.EventArgs e)
{
    // Create a new Form1 and set its Visible property to true.
    Form1 form2 = new Form1();
    form2.Visible = true;

    // Set the new form's desktop location so it  
    // appears below and to the right of the current form.
    form2.SetDesktopLocation(x, y);
    x += 30;
    y += 30;

    // Keep the current form active by calling the Activate
    // method.
    this.Activate();
    this.Button1.Enabled = false;
}



// Updates the label text to reflect the current values of x 
// and y, which was were incremented in the Button1 control's 
// click event.
private void Form1_Activated(object sender,
 System.EventArgs e)
{
    Label1.Text = "x: "+x+" y: "+y;
    Label2.Text = "Number of forms currently open: "+count;
}

static int count = 0;

private void Form1_Closed(object sender, System.EventArgs
 e)
{
    count -= 1;
}

private void Form1_Load(object sender, System.EventArgs
 e)
{
    count += 1;
}

C++

static int x = 200;
static int y = 200;
void Button1_Click( System::Object^ sender, System::EventArgs^
 e )
{
   
   // Create a new Form1 and set its Visible property to true.
   Form1^ form2 = gcnew Form1;
   form2->Visible = true;
   
   // Set the new form's desktop location so it  
   // appears below and to the right of the current form.
   form2->SetDesktopLocation( x, y );
   x += 30;
   y += 30;
   
   // Keep the current form active by calling the Activate
   // method.
   this->Activate();
   this->Button1->Enabled = false;
}


// Updates the label text to reflect the current values of x 
// and y, which was were incremented in the Button1 control's 
// click event.
void Form1_Activated( Object^ sender, System::EventArgs^ e )
{
   Label1->Text = String::Format( "x: {0} y: {1}", x, y );
   Label2->Text = String::Format( "Number of forms currently open: {0}",
 count );
}

static int count = 0;
void Form1_Closed( Object^ sender, System::EventArgs^ e )
{
   count -= 1;
}

void Form1_Load( Object^ sender, System::EventArgs^ e )
{
   count += 1;
}

private static int x = 200;
private static int y = 200;

private void button1_Click(Object sender, System.EventArgs
 e)
{
    // Create a new Form1 and set its Visible property to true.
    Form1 form2 = new Form1();
    form2.set_Visible(true);
    // Set the new form's desktop location so it  
    // appears below and to the right of the current form.
    form2.SetDesktopLocation(x, y);
    x += 30;
    y += 30;
    // Keep the current form active by calling the Activate
    // method.
    this.Activate();
    this.button1.set_Enabled(false);
} //button1_Click

// Updates the label text to reflect the current values of x 
// and y, which was were incremented in the button1 control's 
// click event.
private void Form1_Activated(Object sender,
 System.EventArgs e)
{
    label1.set_Text("x: " + x + " y: " + y);
    label2.set_Text("Number of forms currently open: " + count);
} //Form1_Activated

private static int count
 = 0;

private void Form1_Closed(Object sender, System.EventArgs
 e)
{
    count -= 1;
} //Form1_Closed

private void Form1_Load(Object sender, System.EventArgs
 e)
{
    count += 1;
} //Form1_Load