从DataSource刷新组合框，并保持选定的项目，但不触发SelectedIndexChanged

Question

是刷新组合框的项目，并仍然保持选定的项目，以便SelectedIndexChanged事件不会被触发的方式吗？即使所选项目不在新项目列表中？

以下代码似乎会重置所选项目并触发SelectedIndexChanged事件。

void RefreshComboboxItems() 
{ 
    var ds = GetRefreshedItems(); 
    cb.DataSource = ds; 
    cb.DisplayMember = "Name"; 
    cb.ValueMember = "Value"; 
} 

// cb is already initialized and an item is selected 
RefreshComboboxItems(); // Want to keep the selected item unchanged and don't trigger the event 

Answer 1

如果你想删除的事件处理程序暂时你可以这样做：

void RefreshComboboxItems() 
{ 
    cb.SelectedIndexChanged -= Ddl_SelectedIndexChanged; 

    var ds = GetRefreshedItems(); 
    cb.DataSource = ds; 
    cb.DisplayMember = "Name"; 
    cb.ValueMember = "Value"; 

    cb.SelectedIndexChanged += Ddl_SelectedIndexChanged; 
} 

Answer 2

没有，你可以得到当前的SelectedValue，删除事件处理程序，刷新组合，尝试重新设定的SelectedValue与保存的值，然后重新进行添加事件处理程序

void RefreshComboboxItems() 
{ 
    try 
    { 
     int currentValue = -1; 
     if(cb.SelectedValue != null) 
      currentValue = Convert.ToInt32(cb.SelectedValue); 

     cb.SelectedIndexChanged -= mySelectedIndexChangedMethod; 
     var ds = GetRefreshedItems(); 
     cb.DataSource = ds; 
     cb.DisplayMember = "Name"; 
     cb.ValueMember = "Value"; 

     if(currentValue != -1) 
     cb.SelectedValue = currentValue; 

    } 
    catch(Exception ex) 
    { 
     MessageBox.Show(ex.Message); 
    } 
    finally 
    { 
     cb.SelectedIndexChanged += mySelectedIndexChangedMethod; 
    } 
} 

请注意，我已经重新加入一个内部事件处理程序最后，以确保事件处理程序重新添加哟你的组合框还可以防止在移除事件处理程序后异常导致此代码过早退出