TrackBarRenderer.GetTopPointingThumbSize(Graphics, TrackBarThumbState) 方法

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

傳回指向上方之追蹤列滑桿 (也稱為捲動方塊) 的大小 (以像素為單位)。

public:
 static System::Drawing::Size GetTopPointingThumbSize(System::Drawing::Graphics ^ g, System::Windows::Forms::VisualStyles::TrackBarThumbState state);

public static System.Drawing.Size GetTopPointingThumbSize (System.Drawing.Graphics g, System.Windows.Forms.VisualStyles.TrackBarThumbState state);

static member GetTopPointingThumbSize : System.Drawing.Graphics * System.Windows.Forms.VisualStyles.TrackBarThumbState -> System.Drawing.Size

Public Shared Function GetTopPointingThumbSize (g As Graphics, state As TrackBarThumbState) As Size

參數

g

Graphics

此作業將使用的 Graphics。

state

TrackBarThumbState

其中一個 TrackBarThumbState 值，指定滑桿的可見狀態。

傳回

Size

Size，指定滑桿的大小 (以像素為單位)。

例外狀況

InvalidOperationException

作業系統不支援視覺化樣式。

-或-

使用者已停用作業系統中的視覺化樣式。

-或-

視覺化樣式不適用於應用程式視窗的工作區。

範例

下列程式碼範例會 GetTopPointingThumbSize 使用 方法來判斷 方法用來 DrawTopPointingThumb 繪製滑杆的矩形大小。 此程式碼範例是提供給 類別之較大範例的 TrackBarRenderer 一部分。

    // Calculate the sizes of the bar, thumb, and ticks rectangle.
private:
    void SetupTrackBar()
    {
        if (!TrackBarRenderer::IsSupported)
        {
            return;
        }

        Graphics^ g = this->CreateGraphics();

        // Calculate the size of the track bar.
        trackRectangle.X = ClientRectangle.X + 2;
        trackRectangle.Y = ClientRectangle.Y + 28;
        trackRectangle.Width = ClientRectangle.Width - 4;
        trackRectangle.Height = 4;

        // Calculate the size of the rectangle in which to
        // draw the ticks.
        ticksRectangle.X = trackRectangle.X + 4;
        ticksRectangle.Y = trackRectangle.Y - 8;
        ticksRectangle.Width = trackRectangle.Width - 8;
        ticksRectangle.Height = 4;

        tickSpace = ((float)ticksRectangle.Width - 1) /
            ((float)numberTicks - 1);

        // Calculate the size of the thumb.
        thumbRectangle.Size =
            TrackBarRenderer::GetTopPointingThumbSize(g,
            TrackBarThumbState::Normal);

        thumbRectangle.X = CurrentTickXCoordinate();
        thumbRectangle.Y = trackRectangle.Y - 8;
    }

// Calculate the sizes of the bar, thumb, and ticks rectangle.
private void SetupTrackBar()
{
    if (!TrackBarRenderer.IsSupported)
        return;

    using (Graphics g = this.CreateGraphics())
    {
        // Calculate the size of the track bar.
        trackRectangle.X = ClientRectangle.X + 2;
        trackRectangle.Y = ClientRectangle.Y + 28;
        trackRectangle.Width = ClientRectangle.Width - 4;
        trackRectangle.Height = 4;

        // Calculate the size of the rectangle in which to 
        // draw the ticks.
        ticksRectangle.X = trackRectangle.X + 4;
        ticksRectangle.Y = trackRectangle.Y - 8;
        ticksRectangle.Width = trackRectangle.Width - 8;
        ticksRectangle.Height = 4;

        tickSpace = ((float)ticksRectangle.Width - 1) /
            ((float)numberTicks - 1);

        // Calculate the size of the thumb.
        thumbRectangle.Size =
            TrackBarRenderer.GetTopPointingThumbSize(g,
            TrackBarThumbState.Normal);

        thumbRectangle.X = CurrentTickXCoordinate();
        thumbRectangle.Y = trackRectangle.Y - 8;
    }
}

' Calculate the sizes of the bar, thumb, and ticks rectangle.
Private Sub SetupTrackBar()
    If Not TrackBarRenderer.IsSupported Then
        Return
    End If
    Using g As Graphics = Me.CreateGraphics()
        ' Calculate the size of the track bar.
        trackRectangle.X = ClientRectangle.X + 2
        trackRectangle.Y = ClientRectangle.Y + 28
        trackRectangle.Width = ClientRectangle.Width - 4
        trackRectangle.Height = 4

        ' Calculate the size of the rectangle in which to 
        ' draw the ticks.
        ticksRectangle.X = trackRectangle.X + 4
        ticksRectangle.Y = trackRectangle.Y - 8
        ticksRectangle.Width = trackRectangle.Width - 8
        ticksRectangle.Height = 4

        tickSpace = (CSng(ticksRectangle.Width) - 1) / _
            (CSng(numberTicks) - 1)

        ' Calculate the size of the thumb.
        thumbRectangle.Size = _
            TrackBarRenderer.GetTopPointingThumbSize( _
            g, TrackBarThumbState.Normal)

        thumbRectangle.X = CurrentTickXCoordinate()
        thumbRectangle.Y = trackRectangle.Y - 8
    End Using
End Sub

備註

滑杆的大小取決於作業系統目前的視覺化樣式。

呼叫這個方法之前，您應該先確認 屬性的值 IsSupported 是 true 。