ScrollBarRenderer.DrawHorizontalThumbGrip Método

Definição

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Origem:

ScrollBarRenderer.cs

Desenha uma alça em uma caixa de rolagem horizontal (também conhecida como thumb) com estilos visuais.

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

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

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

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

Parâmetros

g

Graphics

O Graphics usado para desenhar a alça da caixa de rolagem.

bounds

Rectangle

O Rectangle que especifica os limites da alça da caixa de rolagem.

state

ScrollBarState

Um dos valores de ScrollBarState que especifica o estado visual da alça da caixa de rolagem.

Exceções

InvalidOperationException

O sistema operacional não dá suporte a estilos visuais.

- ou -

Os estilos visuais estão desabilitados pelo usuário no sistema operacional.

- ou -

Os estilos visuais não são aplicados à área de cliente das janelas de aplicativos.

Exemplos

O exemplo de código a seguir usa o DrawHorizontalThumbGrip método em um método de OnPaint controle personalizado para desenhar uma alça de caixa de rolagem no estado determinado pelo local do ponteiro do mouse. Este exemplo de código faz parte de um exemplo maior fornecido para a ScrollBarRenderer classe .

    // 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

Comentários

Antes de usar esse método, você deve verificar se a IsSupported propriedade retorna true.