DrawItemEventArgs.DrawBackground Method

Definition

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Source:

DrawItemEventArgs.cs

Draws the background within the bounds specified in the DrawItemEventArgs constructor and with the appropriate color.

C#

public virtual void DrawBackground();

Examples

The following example demonstrates how to create owner-drawn ListBox items. The code uses the DrawMode property to specify that the items drawn are a fixed size and the DrawItem event to perform the drawing of each item into the ListBox. The example code uses the properties and methods of the DrawItemEventArgs class passed as a parameter to the event handler to draw the items. This example assumes that a ListBox control named listBox1 was added to a form and that the DrawItem event is handled by the event handler that is defined in the example code. The example also assumes that items were added to the ListBox with the text of "Apple", "Orange", and "Plum", in that order.

C#

private ListBox ListBox1 = new ListBox();
private void InitializeListBox()
{
    ListBox1.Items.AddRange(new Object[] 
        { "Red Item", "Orange Item", "Purple Item" });
    ListBox1.Location = new System.Drawing.Point(81, 69);
    ListBox1.Size = new System.Drawing.Size(120, 95);
    ListBox1.DrawMode = DrawMode.OwnerDrawFixed;
    ListBox1.DrawItem += new DrawItemEventHandler(ListBox1_DrawItem);
    Controls.Add(ListBox1);
}

private void ListBox1_DrawItem(object sender, 
    System.Windows.Forms.DrawItemEventArgs e)
{
    // Draw the background of the ListBox control for each item.
    e.DrawBackground();
    // Define the default color of the brush as black.
    Brush myBrush = Brushes.Black;

    // Determine the color of the brush to draw each item based 
    // on the index of the item to draw.
    switch (e.Index)
    {
        case 0:
            myBrush = Brushes.Red;
            break;
        case 1:
            myBrush = Brushes.Orange;
            break;
        case 2:
            myBrush = Brushes.Purple;
            break;
    }

    // Draw the current item text based on the current Font 
    // and the custom brush settings.
    e.Graphics.DrawString(ListBox1.Items[e.Index].ToString(), 
        e.Font, myBrush, e.Bounds, StringFormat.GenericDefault);
    // If the ListBox has focus, draw a focus rectangle around the selected item.
    e.DrawFocusRectangle();
}

Remarks

If the item being drawn is Selected, the background is drawn with the text highlighted.

Notes to Inheritors

When overriding DrawBackground() in a derived class, make sure to call the DrawBackground() method of the base class.

Applies to

See also

• DrawItemState