TreeNode图像叠加

Question

我有一个约30张图像的图像列表,当TreeNode处于特定状态时,我希望能够覆盖30个图像的3个图像.我知道C++ TreeItem可以使用TVIS_OVERLAYMASK这样做:

SetItemState(hItem,INDEXTOOVERLAYMASK(nOverlayIndex), TVIS_OVERLAYMASK);

是否有任何机制可以在.NET中实现类似的结果？

Answer 1

我看到这个问题仍然有待观察,所以我将发布大卫建议的实施.

internal class MyTree : TreeView
{
    internal MyTree() :
        base()
    {
        // let the tree know that we're going to be doing some owner drawing
        this.DrawMode = TreeViewDrawMode.OwnerDrawText;
        this.DrawNode += new DrawTreeNodeEventHandler(MyTree_DrawNode);
    }

    void MyTree_DrawNode(object sender, DrawTreeNodeEventArgs e)
    {
        // Do your own logic to determine what overlay image you want to use
        Image overlayImage = GetOverlayImage();

        // you have to move the X value left a bit, 
        // otherwise it will draw over your node text
        // I'm also adjusting to move the overlay down a bit
        e.Graphics.DrawImage(overlayImage,
            e.Node.Bounds.X - 15, e.Node.Bounds.Y + 4);

        // We're done! Draw the rest of the node normally
        e.DefaultDraw = true
    }
}