C＃如何为列表框中的选定项目运行一些代码？

Question

I have a listbox of names, I want to click one of the names so that it is highlighted and then click a button that runs some code for the selected item. How do I call this selected item?

    private void btnEcho_Click(object sender, EventArgs e)
    {
         listbox1.SelectedItem......
    }

Many thanks

Answer 1

列表框不是很直观，因为它包含对象而不是诸如ListItem之类的东西，但是如果您只想要文本，则可以执行以下操作：

string selectedText = listbox1.SelectedItem.ToString();

Answer 2

string str = listbox1.SelectedValue.ToString();

here you have the what value(name) selected.

if(str == null || str == string.empty) return;

and so on. you can do whatever you want; goodluck

Answer 3

String s = listbox1.SelectedItem.Value.ToString();

不要忘记进行空检查，因为如果您的列表为空或未选择任何值，这将引发错误。

Answer 4

Listbox1.SelectedItem gets the actual selected item. You can then further call from SelectedItem to get other properties/methods such as SelectedItem.Text or SelectedItem.Value

If you wanted to make it all happen upon selection from the listbox (instead of pressing a button), you could just add a SelectedIndexChanged event for Listbox1 (and in ASP.NET make sure that AutoPostBack is set to TRUE)

Answer 5

You're question is not clearly to me.

Example, you have a listbox of three items: A, B and C. You have, as you do with your example, a click-event. In that click-event you can use the switch-statement to handle some code for each item:

switch (listbox1.SelectedItem)
{
  case "A":
       // Code when select A
       break;
  case "B":
       // Code when select B
       break;
  ... (and so on).
}

Code is an example and not tested. See switch for more information.