ScrollBarRenderer.DrawHorizontalThumb Methode

Referenz

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Wichtig

Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.

Zeichnet ein horizontales Bildlauffeld (einen Ziehpunkt) mit visuellen Stilen.

public:
 static void DrawHorizontalThumb(System::Drawing::Graphics ^ g, System::Drawing::Rectangle bounds, System::Windows::Forms::VisualStyles::ScrollBarState state);

public static void DrawHorizontalThumb (System.Drawing.Graphics g, System.Drawing.Rectangle bounds, System.Windows.Forms.VisualStyles.ScrollBarState state);

static member DrawHorizontalThumb : System.Drawing.Graphics * System.Drawing.Rectangle * System.Windows.Forms.VisualStyles.ScrollBarState -> unit

Public Shared Sub DrawHorizontalThumb (g As Graphics, bounds As Rectangle, state As ScrollBarState)

Parameter

g: Graphics

Die zum Zeichnen des Bildlauffelds verwendete Graphics.

bounds: Rectangle

Das Rectangle, das die Begrenzungen des Bildlauffelds angibt.

state: ScrollBarState

Einer der ScrollBarState-Werte, der den visuellen Zustand des Bildlauffelds angibt.

Ausnahmen

InvalidOperationException

Das Betriebssystem unterstützt keine visuellen Stile.

- oder -

Visuelle Stile wurden durch den Benutzer im Betriebssystem deaktiviert.

- oder -

Visuelle Stile werden nicht auf den Clientbereich der Anwendungsfenster angewendet.

Beispiele

Im folgenden Codebeispiel wird die DrawHorizontalThumb Methode in der Methode eines benutzerdefinierten Steuerelements OnPaint verwendet, um ein Bildlauffeld im Zustand zu zeichnen, der durch die Position des Mauszeigers bestimmt wird. Dieses Codebeispiel ist Teil eines größeren Beispiels, das für die ScrollBarRenderer Klasse bereitgestellt wird.

    // Draw the scroll bar in its normal state.
protected:
    virtual void OnPaint(PaintEventArgs^ e) override
    {
        __super::OnPaint(e);

        // Visual styles are not enabled.
        if (!ScrollBarRenderer::IsSupported)
        {
            this->Parent->Text = "CustomScrollBar Disabled";
            return;
        }

        this->Parent->Text = "CustomScrollBar Enabled";

        // Draw the scroll bar track.
        ScrollBarRenderer::DrawRightHorizontalTrack(e->Graphics,
            ClientRectangle, ScrollBarState::Normal);

        // Draw the thumb and thumb grip in the current state.
        ScrollBarRenderer::DrawHorizontalThumb(e->Graphics,
            thumbRectangle, thumbState);
        ScrollBarRenderer::DrawHorizontalThumbGrip(e->Graphics,
            thumbRectangle, thumbState);

        // Draw the scroll arrows in the current state.
        ScrollBarRenderer::DrawArrowButton(e->Graphics,
            leftArrowRectangle, leftButtonState);
        ScrollBarRenderer::DrawArrowButton(e->Graphics,
            rightArrowRectangle, rightButtonState);

        // Draw a highlighted rectangle in the left side of the scroll
        // bar track if the user has clicked between the left arrow
        // and thumb.
        if (leftBarClicked)
        {
            clickedBarRectangle.X = thumbLeftLimit;
            clickedBarRectangle.Width = thumbRectangle.X - thumbLeftLimit;
            ScrollBarRenderer::DrawLeftHorizontalTrack(e->Graphics,
                clickedBarRectangle, ScrollBarState::Pressed);
        }

        // Draw a highlighted rectangle in the right side of the scroll
        // bar track if the user has clicked between the right arrow
        // and thumb.
        else if (rightBarClicked)
        {
            clickedBarRectangle.X =
                thumbRectangle.X + thumbRectangle.Width;
            clickedBarRectangle.Width =
                thumbRightLimitRight - clickedBarRectangle.X;
            ScrollBarRenderer::DrawRightHorizontalTrack(e->Graphics,
                clickedBarRectangle, ScrollBarState::Pressed);
        }
    }

// Draw the scroll bar in its normal state.
protected override void OnPaint(PaintEventArgs e)
{
    base.OnPaint(e);

    // Visual styles are not enabled.
    if (!ScrollBarRenderer.IsSupported)
    {
        this.Parent.Text = "CustomScrollBar Disabled";
        return;
    }

    this.Parent.Text = "CustomScrollBar Enabled";

    // Draw the scroll bar track.
    ScrollBarRenderer.DrawRightHorizontalTrack(e.Graphics,
        ClientRectangle, ScrollBarState.Normal);

    // Draw the thumb and thumb grip in the current state.
    ScrollBarRenderer.DrawHorizontalThumb(e.Graphics,
        thumbRectangle, thumbState);
    ScrollBarRenderer.DrawHorizontalThumbGrip(e.Graphics,
        thumbRectangle, thumbState);

    // Draw the scroll arrows in the current state.
    ScrollBarRenderer.DrawArrowButton(e.Graphics,
            leftArrowRectangle, leftButtonState);
    ScrollBarRenderer.DrawArrowButton(e.Graphics,
            rightArrowRectangle, rightButtonState);

    // Draw a highlighted rectangle in the left side of the scroll 
    // bar track if the user has clicked between the left arrow 
    // and thumb.
    if (leftBarClicked)
    {
        clickedBarRectangle.X = thumbLeftLimit;
        clickedBarRectangle.Width = thumbRectangle.X - thumbLeftLimit;
        ScrollBarRenderer.DrawLeftHorizontalTrack(e.Graphics,
            clickedBarRectangle, ScrollBarState.Pressed);
    }

    // Draw a highlighted rectangle in the right side of the scroll 
    // bar track if the user has clicked between the right arrow 
    // and thumb.
    else if (rightBarClicked)
    {
        clickedBarRectangle.X =
            thumbRectangle.X + thumbRectangle.Width;
        clickedBarRectangle.Width =
            thumbRightLimitRight - clickedBarRectangle.X;
        ScrollBarRenderer.DrawRightHorizontalTrack(e.Graphics,
            clickedBarRectangle, ScrollBarState.Pressed);
    }
}

' Draw the scroll bar in its normal state.
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
    MyBase.OnPaint(e)

    ' Visual styles are not enabled.
    If Not ScrollBarRenderer.IsSupported Then
        Me.Parent.Text = "CustomScrollBar Disabled"
        Return
    End If

    Me.Parent.Text = "CustomScrollBar Enabled"

    ' Draw the scroll bar track.
    ScrollBarRenderer.DrawRightHorizontalTrack(e.Graphics, _
        Me.ClientRectangle, ScrollBarState.Normal)

    ' Draw the thumb and thumb grip in the current state.
    ScrollBarRenderer.DrawHorizontalThumb(e.Graphics, _
        thumbRectangle, thumbState)
    ScrollBarRenderer.DrawHorizontalThumbGrip(e.Graphics, _
        thumbRectangle, thumbState)

    ' Draw the scroll arrows in the current state.
    ScrollBarRenderer.DrawArrowButton(e.Graphics, _
        leftArrowRectangle, leftButtonState)
    ScrollBarRenderer.DrawArrowButton(e.Graphics, _
        rightArrowRectangle, rightButtonState)

    ' Draw a highlighted rectangle in the left side of the scroll 
    ' bar track if the user has clicked between the left arrow 
    ' and thumb.
    If leftBarClicked Then
        clickedBarRectangle.X = thumbLeftLimit
        clickedBarRectangle.Width = thumbRectangle.X - thumbLeftLimit
        ScrollBarRenderer.DrawLeftHorizontalTrack(e.Graphics, _
            clickedBarRectangle, ScrollBarState.Pressed)

    ' Draw a highlighted rectangle in the right side of the scroll 
    ' bar track if the user has clicked between the right arrow 
    ' and thumb.
    ElseIf rightBarClicked Then
        clickedBarRectangle.X = thumbRectangle.X + _
            thumbRectangle.Width
        clickedBarRectangle.Width = thumbRightLimitRight - _
            clickedBarRectangle.X
        ScrollBarRenderer.DrawRightHorizontalTrack(e.Graphics, _
            clickedBarRectangle, ScrollBarState.Pressed)
    End If
End Sub

Hinweise

Bevor Sie diese Methode verwenden, sollten Sie überprüfen, ob die IsSupported Eigenschaft zurückgegeben wird true.

Gilt für

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