首页 \ 问答 \ Java Jtree mouseEvent如果没有选择任何内容(Java Jtree mouseEvent if nothing is selected)

Java Jtree mouseEvent如果没有选择任何内容(Java Jtree mouseEvent if nothing is selected)

我试图弄清楚如何编写一个事件,如果在Swing JTree中单击并且鼠标没有点击树中的任何内容,则获得一个“无”的println。

假设我有一个带有AWT.event.Mouwesvent的树'info_tree':

private void info_treeMouseClicked(java.awt.event.MouseEvent evt) {   
    if(info_tree.getSelectionPath() /*something along the lines of is empty or if !info_tree.getSelectionPath().isEmpty()*/
       ){system.out.println("Nothing");
      }else{
          system.out.println("Something");
      }
}

我找不到任何比较树的selectedPath或元素的东西。


I am trying to figure out how to code a event that, if clicked in a Swing JTree and the mouse does not click anything in the tree, to get a println that says "nothing".

Say I have a tree 'info_tree' with an AWT.event.Mouwesvent as such:

private void info_treeMouseClicked(java.awt.event.MouseEvent evt) {   
    if(info_tree.getSelectionPath() /*something along the lines of is empty or if !info_tree.getSelectionPath().isEmpty()*/
       ){system.out.println("Nothing");
      }else{
          system.out.println("Something");
      }
}

I can't find anything to compare a selectedPath or element of a tree.


原文:https://stackoverflow.com/questions/33150974
更新时间:2020-10-25 11:10

最满意答案

你可以尝试一下

If (info_tree.getSelectionPath()==null)

但是,您可能想要切换输出线。 因为原样是真/假的条件。 如果是假,它会转到其他地方。 这也可以解决它。


You may wish to try

If (info_tree.getSelectionPath()==null)

But,then you may want to switch your output lines around. Because that as-is is a true/false condition. If false it'll goto else. That could solve it as well.

2015-10-15

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