如何在不选择所有节点的情况下禁用TreeView控件? [英] How to disable a TreeView control without selecting all nodes?

问题描述

我不知道这是错误还是其他原因，但是如果我尝试禁用 TTreeView 控件，则所有节点都将被选中(显示为灰色)...只是在不更改选择的情况下禁用此控件的输入?当然，并没有真正选择节点，只是在视觉上选择了节点，但这很烦人.

I don't know if this is a bug or something, but if I try to disable a TTreeView control, all the nodes become selected (grayed out)... Can anything be done to just disable the input for this control without changing the selection ? Of course, the node are not really selected, they are just visually selected, but this is annoying.

推荐答案

这就是未应用主题时禁用控件的外观.您可以在几乎不干预项目图纸的情况下对其进行修改:

That's how the disabled control looks like when no theme is applied. You can modify it with little intervention to item drawing:

procedure TForm1.TreeView1AdvancedCustomDrawItem(Sender: TCustomTreeView;
  Node: TTreeNode; State: TCustomDrawState; Stage: TCustomDrawStage;
  var PaintImages, DefaultDraw: Boolean);
begin
  if (not TreeView1.Enabled) and
      (GetWindowTheme(TreeView1.Handle) = 0) and (Stage = cdPrePaint) then begin
    TreeView1.Canvas.Brush.Color := clWindow; // or TreeView1.Color
    TreeView1.Canvas.Font.Color := clGrayText;
  end;
end;

不幸的是， State 从未包含'cdsDisabled'或'cdsGrayed'(我没有研究过)，因此代码测试了是否启用了树视图.

Unfortunately the State never includes 'cdsDisabled' or 'cdsGrayed' (which I didn't investigate), so the code tests if the treeview is enabled or not.

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