在C#中分配treeview.selectedNode的问题 [英] problem assigning treeview.selectedNode in C#
问题描述
我想在C#中设置treeView.selectedNode,我希望在处理此分配时发生beforeSelect事件。但我的问题是我在下面描述的:
当我使用下面的代码时,发生了beforeSelect事件,并将其称为''函数。
this .treeView1.SelectedNode = treeView1.Nodes [Level1Index];
this .treeView1.SelectedNode = treeView1.SelectedNode.Nodes [Level2Index];
但是当我使用如下的时候它没有发生。
this .treeView1.SelectedNode = treeView1.Nodes [Level1Index] .Nodes [Level2Index];
为什么?
您应该将获得的节点分配到变量中,以便在调试时可以看到它们的内容(F5)。
TreeViewNode node1 = treeView1.Nodes [Level1Index];
TreeViewNode node2 = treeView1.Nodes [Level2Index];
从这里,在调试器中看到你的node1
和node2
变量包含;你将对你的问题有一个更好的了解。
我仔细检查,你的场景以及何时设置SelectedNode而不管它的层次结构如何,它总是触发BeforeSelected事件。
很可能treeView1.Nodes [Level1Index] .Nodes [Level2Index];为空。如果它为null则不会选择该节点,因此不会触发BeforeSelected事件。
问候
Jegan
I want to set treeView.selectedNode programlly in C# and I want to be occured the beforeSelect event while proccessing this assigning. but my question is what I describe below:
when I use the code bellow, the beforeSelect event occured and call it''s function.
this.treeView1.SelectedNode = treeView1.Nodes[Level1Index];
this.treeView1.SelectedNode=treeView1.SelectedNode.Nodes[Level2Index];
but when I use such as bellow It doese''nt occure.
this.treeView1.SelectedNode = treeView1.Nodes[Level1Index].Nodes[Level2Index];
why?
You should assign your obtained nodes into variables so that you can see their content while debugging (F5).
TreeViewNode node1 = treeView1.Nodes[Level1Index]; TreeViewNode node2 = treeView1.Nodes[Level2Index];
From here, see in the the debugger what yournode1
andnode2
variables contain ; you will have a better understanding about your problem.
Hi,
I double checked, your scenario and when the SelectedNode is set regardless of its hierarchy, it always trigger the BeforeSelected event.
It is most likely that thetreeView1.Nodes[Level1Index].Nodes[Level2Index];is null. if it is null then the node will not be selected and so the BeforeSelected event will not be triggered.
Regards
Jegan
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