自定义树视图 [英] Customize treeview

问题描述

有没有办法自定义一个 winform 树视图来获得类似的东西?

Is there a way to customize a winform treeview to get something like ?

目的是让父项具有一种颜色，并定义一个三角形而不是 +/- 图标来展开项.

The purpose is to have one color by parent item an define a triangle instead of +/- icons to develop item.

推荐答案

使用 TreeViewDrawMode.OwnerDrawText 这样缩进将被 TreeView 调整.除此之外，你应该实现完整的绘画.

Use TreeViewDrawMode.OwnerDrawText so the indenting will be adjusted by the TreeView. Apart from that, you should implement the full painting.

public sealed class AdvancedTreeView : TreeView
{
    public AdvancedTreeView()
    {
        DrawMode = TreeViewDrawMode.OwnerDrawText;
        ShowLines = false;
        AlternateBackColor = BackColor;
    }

    public Color AlternateBackColor { get; set; }

    protected override void OnDrawNode(DrawTreeNodeEventArgs e)
    {
        // background
        Color backColor = (GetTopNodeIndex(e.Node) & 1) == 0 ? BackColor : AlternateBackColor;
        using (Brush b = new SolidBrush(backColor))
        {
            e.Graphics.FillRectangle(b, new Rectangle(0, e.Bounds.Top, ClientSize.Width, e.Bounds.Height));
        }

        // icon
        if (e.Node.Nodes.Count > 0)
        {
            Image icon = GetIcon(e.Node.IsExpanded); // TODO: true=down;false:right
            e.Graphics.DrawImage(icon, e.Bounds.Left - icon.Width - 3, e.Bounds.Top);
        }

        // text (due to OwnerDrawText mode, indenting of e.Bounds will be correct)
        TextRenderer.DrawText(e.Graphics, e.Node.Text, Font, e.Bounds, ForeColor);

        // indicate selection (if not by backColor):
        if ((e.State & TreeNodeStates.Selected) != 0)
            ControlPaint.DrawFocusRectangle(e.Graphics, e.Bounds);
    }

    private int GetTopNodeIndex(TreeNode node)
    {
        while (node.Parent != null)
            node = node.Parent;

        return Nodes.IndexOf(node);
    }
}

要获得与屏幕截图类似的结果，只需设置颜色即可.

To get the result similar to your screenshot just set the colors and you are done.

advancedTreeView1.BackColor = Color.DeepSkyBlue;
advancedTreeView1.AlternateBackColor = Color.LightBlue;

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