Get the text of the selected item in a WPF listbox

Question

I have a data bound listbox in a WPF control. All I want is the text of the selected index. If I use SelectedItem.ToString I get the key and text. If I use SelectedValue.ToString I get just the key.

A few forums have suggested casting like below but that doesn't seem to be working.

InputName nameInput = new InputName((ListBoxItem)LbContractors.SelectedItem.ToString()));

This is how I am binding the control. Is that messing it up.

LbContractors.ItemsSource = myDictionary;
LbContractors.SelectedValuePath = "Key";
LbContractors.DisplayMemberPath = "Value";

Answer 1

This should do the trick.

(LbContractors.SelectedItem as ListBoxItem).Content.ToString();

UPDATE

Or try to do this. Convert to Nullable KeyValuePair and get the Value.

var kvp = (KeyValuePair<string, object>?) LbContractors.SelectedItem);
if(kvp != null && kvp.Value != null) {
    string selectedText = kvp.Value.ToString();
}

In one line with null checking :)

string selectedText = ((KeyValuePair<string, object>?) LbContractors.SelectedItem)?.Value?.ToString();

Answer 2

  

为什么我不能像在winform中那样简单地抓取文本

如果对象被正确取消引用，就可以了....

  

我想要的只是所选索引的文本。

但是，根据您的示例，键值对结构的ToString()文本应该返回什么？你有ToString()超载吗？

要解决的两个问题

1. 您确定SelectedItem不为空吗？在访问之前检查该条件。
2. 应该转换为适当的结构（KVP），而不是盲目地调用ToString()和引用 Key或Value的相应属性。

否则这里有例子。第一个是绑定到字典的列表框

myDictionary = new Dictionary<string, string>()
                {
                    {"Alpha", "The First Letter"},
                    {"Beta", "The Second Letter"},
                    {"Omega", "Omega Letter"},
                };

当用户选择每个项目时，键和值将显示在列表框下方的文本框中：



<强>的Xaml

<ListBox  Name="lbDictionary"
          ItemsSource="{Binding myDictionary}"
          SelectedValuePath="Key"
          DisplayMemberPath="Value"/>

在文本框中访问它们（我没有为了简洁而显示“Key”和“Value”的标签）

<TextBlock Text="{Binding SelectedItem.Key, ElementName=lbDictionary}"/>
...
<TextBlock Text="{Binding SelectedItem.Value, ElementName=lbDictionary}"/>

因此，Key背后的代码访问权限是这样的，Value将是相同的：

if (lbDictionary.SelectedItem != null)
    MessageBox.Show(((KeyValuePair<string, string>) (lbDictionary.SelectedItem)).Key);
else
    MessageBox.Show("Select something");

Answer 3

Why not use LblContractors.Text; if that's all you're looking for?