这是这个问题的扩展 C# override OnDrawItem 我已经制作了这个自定义组合框类
class LineStyleComboBox: System.Windows.Forms.ComboBox
{
Pen SolidPen;
Pen DashedPen;
public LineStyleComboBox()
{
this.DropDownStyle = ComboBoxStyle.DropDownList;
this.DrawMode = DrawMode.OwnerDrawFixed;
}
protected override void OnDrawItem(DrawItemEventArgs e)
{
float[] dashValues = { 5, 2, 15, 4 };
if (e.Index > -1)
{
int startX = e.Bounds.Left + 5;
int startY = (e.Bounds.Y + e.Bounds.Height / 2);
int endX = e.Bounds.Right - 5;
int endY = (e.Bounds.Y + e.Bounds.Height / 2);
using ( SolidPen = new Pen(Color.Blue, (Int32)this.Items[e.Index]))
{
e.Graphics.DrawLine(SolidPen, new Point(startX, startY), new Point(endX, endY));
}
using ( DashedPen = new Pen(Color.Blue, (Int32)this.Items[e.Index]))
{
e.Graphics.DrawLine(DashedPen, new Point(startX, startY), new Point(endX, endY));
DashedPen.DashPattern = dashValues;
}
}
base.OnDrawItem(e);
}
}
在我需要使用此 LineStyleComboBox 的另一种形式中,如何将笔样式集合添加为项目。这样我就可以实现一个带有线条样式的组合框作为项目(实心笔,虚线笔)。
private void frmDlgGraphOptions_Load(object sender, EventArgs e)
{
lineStyleComboBox2.Items.Add(solidpen,dashed pen)
}