WPF Combo box 获取选择的Tag

string str1 = ((ComboBoxItem)this.cboBoxRate1553B.Items[this.cboBoxRate1553B.SelectedIndex]).Tag.ToString();

string str2 = (this.cboBoxRate1553B.SelectedItem as ComboBoxItem).Tag.ToString();

不知道为什么只能先转换为var 或者string类型，再转化为其他类型。

I have a combo box like this

    <ComboBox Name="myMenu">
        <ComboBoxItem Content="Question 1" Tag="1"  />
        <ComboBoxItem Content="Question 2" Tag="2"  />
        <ComboBoxItem Content="Question 3" Tag="3"  />
        <ComboBoxItem Content="Question 4" Tag="4"  />
    </ComboBox>

How can I programmatically set the selected index by Tag Value? E.g. 'myMenu.selectedTag = 3' and Question 3 would be the selected item?

I want something easier than my current solution really...

      int tagToSelect = 3;
      foreach (ComboBoxItem item in myMenu.Items)
      {
          if(item.Tag.Equals(tagToSelect)
          {
               myMenu.SelectedItem = item;
          }
      }