TrackBar.Scroll 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

TrackBar.Scroll イベント

マウス操作またはキー操作でスクロールボックスが移動すると発生します。

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 Scroll As EventHandler

Visual Basic (使用法)

Dim instance As TrackBar
Dim handler As EventHandler

AddHandler instance.Scroll, handler

public event EventHandler Scroll

C++

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

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

/** @event */
public void remove_Scroll (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

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

Scroll イベントを実装し、トラックバーのスクロールボックスのスクロールに応じて、フォーム上の情報ラベルを変更する方法を次のコード例に示します。この例では、Form に 3 つのトラックバーと 3 つのラベルが配置されている必要があります。

Visual Basic

Private Sub showColorValueLabels()
    label1.Text = "Red value is : " & trackBar1.Value.ToString()
    label3.Text = "Green Value is : " & trackBar2.Value.ToString()
    label2.Text = "Blue Value is : " & trackBar3.Value.ToString()
End Sub

Private Sub trackBar_Scroll(ByVal
 sender As Object, ByVal
 e As System.EventArgs) Handles trackBar1.Scroll, trackBar2.Scroll, trackBar3.Scroll
    Dim myTB As System.Windows.Forms.TrackBar
    myTB = sender
    panel1.BackColor = Color.FromArgb(trackBar1.Value, trackBar2.Value, trackBar3.Value)
    myTB.Text = "Value is " & myTB.Value.ToString()
    showColorValueLabels()
End Sub

private void showColorValueLabels()
{
    label1.Text = "Red value is : " + trackBar1.Value.ToString();
    label3.Text = "Green Value is : " + trackBar2.Value.ToString();
    label2.Text = "Blue Value is : " + trackBar3.Value.ToString();
}
private void trackBar_Scroll(object sender,
 System.EventArgs e)
{
    System.Windows.Forms.TrackBar myTB;
    myTB = (System.Windows.Forms.TrackBar) sender ;
    panel1.BackColor = Color.FromArgb(trackBar1.Value,trackBar2.Value,trackBar3.Value);
    myTB.Text = "Value is " + myTB.Value.ToString();
    showColorValueLabels();
}

C++

void showColorValueLabels()
{
   label1->Text = String::Format( "Red value is : {0}", trackBar1->Value
 );
   label3->Text = String::Format( "Green Value is : {0}", trackBar2->Value
 );
   label2->Text = String::Format( "Blue Value is : {0}", trackBar3->Value
 );
}

void trackBar_Scroll( Object^ sender, System::EventArgs^ /*e*/
 )
{
   System::Windows::Forms::TrackBar^ myTB;
   myTB = dynamic_cast<System::Windows::Forms::TrackBar^>(sender);
   panel1->BackColor = Color::FromArgb( trackBar1->Value, trackBar2->Value,
 trackBar3->Value );
   myTB->Text = String::Format( "Value is {0}", myTB->Value );
   showColorValueLabels();
}

private void ShowColorValueLabels()
{
    label1.set_Text("Red value is : "
        + ((Int32)trackBar1.get_Value()).ToString());
    label3.set_Text("Green Value is : "
        + ((Int32)trackBar2.get_Value()).ToString());
    label2.set_Text("Blue Value is : "
        + ((Int32)trackBar3.get_Value()).ToString());
} //ShowColorValueLabels

private void trackBar_Scroll(Object sender,
 System.EventArgs e)
{
    System.Windows.Forms.TrackBar myTB;
    myTB = (System.Windows.Forms.TrackBar)sender;
    panel1.set_BackColor(Color.FromArgb(trackBar1.get_Value(),
        trackBar2.get_Value(), trackBar3.get_Value()));
    myTB.set_Text("Value is " + ((Int32)myTB.get_Value()).ToString());
    ShowColorValueLabels();
} //trackBar_Scroll

TrackBar コントロールと TextBox コントロールが配置されたフォームを表示するコード例を次に示します。この例では、Maximum、TickFrequency、LargeChange、SmallChange の各プロパティを設定して、Scroll イベントを処理しています。TextBox の内容は、Scroll イベントが発生したときに、Value プロパティの値に更新されます。

Visual Basic

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

Public Class Form1
    Inherits System.Windows.Forms.Form

    Private WithEvents trackBar1 As
 System.Windows.Forms.TrackBar
    Private textBox1 As System.Windows.Forms.TextBox

    <System.STAThread()> _
    Public Shared Sub Main()
        System.Windows.Forms.Application.Run(New Form1)
    End Sub 'Main

    Public Sub New()
        Me.textBox1 = New System.Windows.Forms.TextBox
        Me.trackBar1 = New System.Windows.Forms.TrackBar

        ' TextBox for TrackBar.Value update.
        Me.textBox1.Location = New System.Drawing.Point(240,
 16)
        Me.textBox1.Size = New System.Drawing.Size(48,
 20)

        ' Set up how the form should be displayed and add the controls
 to the form.
        Me.ClientSize = New System.Drawing.Size(296,
 62)
        Me.Controls.AddRange(New System.Windows.Forms.Control()
 {Me.textBox1, Me.trackBar1})
        Me.Text = "TrackBar Example"

        ' Set up the TrackBar.
        Me.trackBar1.Location = New System.Drawing.Point(8,
 8)
        Me.trackBar1.Size = New System.Drawing.Size(224,
 45)

        ' The Maximum property sets the value of the track bar when
        ' the slider is all the way to the right.
        trackBar1.Maximum = 30

        ' The TickFrequency property establishes how many positions
        ' are between each tick-mark.
        trackBar1.TickFrequency = 5

        ' The LargeChange property sets how many positions to move
        ' if the bar is clicked on either side of the slider.
        trackBar1.LargeChange = 3

        ' The SmallChange property sets how many positions to move
        ' if the keyboard arrows are used to move the slider.
        trackBar1.SmallChange = 2
    End Sub 'New

    Private Sub trackBar1_Scroll(ByVal
 sender As Object, _
                    ByVal e As System.EventArgs)
 Handles trackBar1.Scroll

        ' Display the trackbar value in the text box.
        textBox1.Text = trackBar1.Value
    End Sub 

End Class 'Form1

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

public class Form1 : System.Windows.Forms.Form
{
    private System.Windows.Forms.TrackBar trackBar1;
    private System.Windows.Forms.TextBox textBox1;

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

    public Form1()
    {
        this.textBox1 = new System.Windows.Forms.TextBox();
        this.trackBar1 = new System.Windows.Forms.TrackBar();

        // TextBox for TrackBar.Value update.
        this.textBox1.Location = new System.Drawing.Point(240,
 16);
        this.textBox1.Size = new System.Drawing.Size(48,
 20);

        // Set up how the form should be displayed and add the controls
 to the form.
        this.ClientSize = new System.Drawing.Size(296,
 62);
        this.Controls.AddRange(new System.Windows.Forms.Control[]
 {this.textBox1,this.trackBar1});
        this.Text = "TrackBar Example";

        // Set up the TrackBar.
        this.trackBar1.Location = new System.Drawing.Point(8,
 8);
        this.trackBar1.Size = new System.Drawing.Size(224,
 45);
        this.trackBar1.Scroll += new System.EventHandler(this.trackBar1_Scroll);

        // The Maximum property sets the value of the track bar when
        // the slider is all the way to the right.
        trackBar1.Maximum = 30;
        
        // The TickFrequency property establishes how many positions
        // are between each tick-mark.
        trackBar1.TickFrequency = 5;

        // The LargeChange property sets how many positions to move
        // if the bar is clicked on either side of the slider.
        trackBar1.LargeChange = 3;

        // The SmallChange property sets how many positions to move
        // if the keyboard arrows are used to move the slider.
        trackBar1.SmallChange = 2;
    }


    private void trackBar1_Scroll(object sender,
 System.EventArgs e)
    {
        // Display the trackbar value in the text box.
        textBox1.Text = "" + trackBar1.Value;
    }
}

C++

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::TrackBar^ trackBar1;
   System::Windows::Forms::TextBox^ textBox1;

public:
   Form1()
   {
      this->textBox1 = gcnew System::Windows::Forms::TextBox;
      this->trackBar1 = gcnew System::Windows::Forms::TrackBar;
      
      // TextBox for TrackBar::Value update.
      this->textBox1->Location = System::Drawing::Point(
 240, 16 );
      this->textBox1->Size = System::Drawing::Size( 48,
 20 );
      
      // Set up how the form should be displayed and add the controls
 to the form.
      this->ClientSize = System::Drawing::Size( 296, 62 );
      array<System::Windows::Forms::Control^>^formControls = {this->textBox1
,this->trackBar1};
      this->Controls->AddRange( formControls );
      this->Text = "TrackBar Example";
      
      // Set up the TrackBar.
      this->trackBar1->Location = System::Drawing::Point(
 8, 8 );
      this->trackBar1->Size = System::Drawing::Size( 224,
 45 );
      this->trackBar1->Scroll += gcnew System::EventHandler(
 this, &Form1::trackBar1_Scroll );
      
      // The Maximum property sets the value of the track bar when
      // the slider is all the way to the right.
      trackBar1->Maximum = 30;
      
      // The TickFrequency property establishes how many positions
      // are between each tick-mark.
      trackBar1->TickFrequency = 5;
      
      // The LargeChange property sets how many positions to move
      // if the bar is clicked on either side of the slider.
      trackBar1->LargeChange = 3;
      
      // The SmallChange property sets how many positions to move
      // if the keyboard arrows are used to move the slider.
      trackBar1->SmallChange = 2;
   }


private:
   void trackBar1_Scroll( Object^ /*sender*/, System::EventArgs^
 /*e*/ )
   {
      
      // Display the trackbar value in the text box.
      textBox1->Text = String::Concat( "", trackBar1->Value );
   }

};


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

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

public class Form1 extends System.Windows.Forms.Form
{
    private System.Windows.Forms.TrackBar trackBar1;
    private System.Windows.Forms.TextBox textBox1;

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

    public Form1()
    {
        this.textBox1 = new System.Windows.Forms.TextBox();
        this.trackBar1 = new System.Windows.Forms.TrackBar();
        // TextBox for TrackBar.Value update.
        this.textBox1.set_Location(new System.Drawing.Point(240,
 16));
        this.textBox1.set_Size(new System.Drawing.Size(48,
 20));
        // Set up how the form should be displayed and add the controls
 to the
        // form.
        this.set_ClientSize(new System.Drawing.Size(296,
 62));
        this.get_Controls().AddRange(new System.Windows.Forms.Control[]
 { 
            this.textBox1, this.trackBar1 });
        this.set_Text("TrackBar Example");
        // Set up the TrackBar.
        this.trackBar1.set_Location(new System.Drawing.Point(8,
 8));
        this.trackBar1.set_Size(new System.Drawing.Size(224,
 45));
        this.trackBar1.add_Scroll(new System.EventHandler(this.trackBar1_Scroll));
        // The Maximum property sets the value of the track bar when
        // the slider is all the way to the right.
        trackBar1.set_Maximum(30);
        // The TickFrequency property establishes how many positions
        // are between each tick-mark.
        trackBar1.set_TickFrequency(5);
        // The LargeChange property sets how many positions to move
        // if the bar is clicked on either side of the slider.
        trackBar1.set_LargeChange(3);
        // The SmallChange property sets how many positions to move
        // if the keyboard arrows are used to move the slider.
        trackBar1.set_SmallChange(2);
    } //Form1

    private void trackBar1_Scroll(Object sender,
 System.EventArgs e)
    {
        // Display the trackbar value in the text box.
        textBox1.set_Text("" + trackBar1.get_Value());
    } //trackBar1_Scroll
} //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 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
TrackBar クラス
TrackBar メンバ
System.Windows.Forms 名前空間

>> 「TrackBar.Scroll イベント」を含む用語の索引
TrackBar.Scroll イベントのページへのリンク


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TrackBar.Scroll イベントとは？ わかりやすく解説

TrackBar.Scroll イベント

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TrackBar.Scroll イベントとは？わかりやすく解説