DrawTopPointingThumb Method

TrackBarRenderer.DrawTopPointingThumb Method (Graphics, Rectangle, TrackBarThumbState)

 

Draws an upward-pointing track bar slider (also known as the thumb) with visual styles.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public static void DrawTopPointingThumb(
	Graphics g,
	Rectangle bounds,
	TrackBarThumbState state
)

Parameters

g
Type: System.Drawing.Graphics

The Graphics used to draw the track bar slider.

bounds
Type: System.Drawing.Rectangle

The Rectangle that specifies the bounds of the track bar slider.

state
Type: System.Windows.Forms.VisualStyles.TrackBarThumbState

One of the TrackBarThumbState values that specifies the visual state of the track bar slider.

Exception Condition
InvalidOperationException

The operating system does not support visual styles.

-or-

Visual styles are disabled by the user in the operating system.

-or-

Visual styles are not applied to the client area of application windows.

Before calling this method, you should verify that the value of the IsSupported property is true.

The following code example uses the DrawTopPointingThumb method in a custom control's OnPaint method to draw an upward-pointing track bar slider. This code example is part of a larger example provided for the TrackBarRenderer class.

// Draw the track bar.
protected override void OnPaint(PaintEventArgs e)
{
    if (!TrackBarRenderer.IsSupported)
    {
        this.Parent.Text = "CustomTrackBar Disabled";
        return;
    }

    this.Parent.Text = "CustomTrackBar Enabled";
    TrackBarRenderer.DrawHorizontalTrack(e.Graphics,
        trackRectangle);
    TrackBarRenderer.DrawTopPointingThumb(e.Graphics,
        thumbRectangle, thumbState);
    TrackBarRenderer.DrawHorizontalTicks(e.Graphics,
        ticksRectangle, numberTicks, EdgeStyle.Raised);
}

// Determine whether the user has clicked the track bar thumb.
protected override void OnMouseDown(MouseEventArgs e)
{
    if (!TrackBarRenderer.IsSupported)
        return;

    if (this.thumbRectangle.Contains(e.Location))
    {
        thumbClicked = true;
        thumbState = TrackBarThumbState.Pressed;
    }

    this.Invalidate();
}

.NET Framework
Available since 2.0
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