如何更改打开的ToolStripDropDownButton的背景颜色？

Question

ToolStripDropDownButton当打开下拉菜单时,我需要更改a的背景颜色.我该怎么做？

我尝试从中继承一个类ToolStripProfessionalRenderer然后覆盖它OnRenderDropDownButtonBackground,但它只影响下拉菜单何时关闭.

Answer 1

我相信你可以使用以下方法:

第一种方法:

toolStripDropDownButton1.Paint += toolStripDropDownButton1_Paint;
//...
void toolStripDropDownButton1_Paint(object sender, PaintEventArgs e) {
    if(toolStripDropDownButton1.Pressed) {
        // TODO Paint your pressed button
        e.Graphics.FillRectangle(Brushes.Green, e.ClipRectangle);
    }
}

第二种方法:

toolStrip.Renderer = new PressedRenderer();
//...    

class PressedRenderer : ToolStripProfessionalRenderer {
    protected override void OnRenderDropDownButtonBackground(ToolStripItemRenderEventArgs e) {
        if(e.Item.Pressed)
            e.Graphics.Clear(Color.Green);
        else base.OnRenderDropDownButtonBackground(e);
    }
}