TrackBar-Klasse
Stellt eine Standardtrackleiste von Windows dar.
Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)
Syntax
'Declaration
<ComVisibleAttribute(True)> _
<ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch)> _
Public Class TrackBar
Inherits Control
Implements ISupportInitialize
'Usage
Dim instance As TrackBar
[ComVisibleAttribute(true)]
[ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch)]
public class TrackBar : Control, ISupportInitialize
[ComVisibleAttribute(true)]
[ClassInterfaceAttribute(ClassInterfaceType::AutoDispatch)]
public ref class TrackBar : public Control, ISupportInitialize
/** @attribute ComVisibleAttribute(true) */
/** @attribute ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch) */
public class TrackBar extends Control implements ISupportInitialize
ComVisibleAttribute(true)
ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch)
public class TrackBar extends Control implements ISupportInitialize
Hinweise
Bei der TrackBar handelt es sich um ein bildlauffähiges Steuerelement, das dem ScrollBar-Steuerelement ähnelt. Sie können Bereiche konfigurieren, die der Wert der Value-Eigenschaft einer Trackleiste im Bildlauf durchläuft, indem Sie für das unteren Ende des Bereichs die Minimum-Eigenschaft für das obere Ende des Bereichs die Maximum-Eigenschaft festlegen.
Die LargeChange-Eigenschaft definiert den inkrementellen Wert, der beim Klicken auf eine Seite des Bildlauffelds von der Value-Eigenschaft subtrahiert oder zu ihr addiert wird. Die Trackleiste kann horizontal oder vertikal angezeigt werden.
Mithilfe dieses Steuerelement können Sie numerische Daten eingeben, die durch die Value-Eigenschaft abgerufen werden. Sie können diese numerischen Daten in einem Steuerelement anzeigen oder im Code verwenden.
Beispiel
Im folgenden Codebeispiel wird ein Formular mit einem TrackBar-Steuerelement und einem TextBox-Steuerelement angezeigt. Im Beispiel wird das Festlegen der Eigenschaften Maximum, TickFrequency, LargeChange und SmallChange sowie die Behandlung des Scroll-Ereignisses veranschaulicht. Der Inhalt von TextBox wird auf den Value-Eigenschaftenwert aktualisiert, wenn das Scroll-Ereignis eintritt.
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;
}
}
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
Vererbungshierarchie
System.Object
System.MarshalByRefObject
System.ComponentModel.Component
System.Windows.Forms.Control
System.Windows.Forms.TrackBar
Threadsicherheit
Alle öffentlichen statischen (Shared in Visual Basic) Member dieses Typs sind threadsicher. Bei Instanzmembern ist die Threadsicherheit nicht gewährleistet.
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
.NET Compact Framework
Unterstützt in: 2.0, 1.0