WAPF更改事件中的TextBox更改事件 [英] TextBox change Event in wpf Change Event

问题描述

您好，

我在wpf c＃window应用程序中有一个文本框。我在c＃中动态地在数据网格中创建它。我已经在该文本框中附加了一个事件处理程序。但问题是当控件加载到其中时，文本框事件被无限调用...完成代码正在c＃中完成只...我没有使用xaml ...每个文本框都是动态创建的....注意：文本框出现在数据网格中...请帮助我yar ...

  private   void  txtUnitCount_Changed（  object  Sender，TextChangedEventArgs e）
 {
  try  
 {
  int  index =  0 ; 
  int  rowIndex = -1; 
 TextBox txt = Sender  as  TextBox; 
  int  Units = Convert.ToInt32（txt.Text）; 
 
  for （index =  1 ; index <  dsBillingDetails.Tables.Count; index ++）
 {
 DataRowCollection rowCol = dsBillingDetails.Tables [index] .Rows; 
 
 DataRow [] DataRows = dsBillingDetails.Tables [index] .Select（find）; 
  if （DataRows.Count（）>   0 ）
 {
 DataRow foundRow = DataRows [ 0 ]; 
 
 rowIndex = rowCol.IndexOf（foundRow）; 
  if （rowIndex！= -1）
 {
 
  / /  此行导致问题，即行下面 
 dsBillingDetails.Tables [index] .AcceptChanges（）; 
 
} 
 
  break ; 
} 
} 
 
 
} 
  catch （例外情况）
 {
} 
} 
 

解决方案

请查看我的问题并做出相应澄清。现在，我将回答你的一个后续问题：

jing111写道：

...让我知道如何将处理程序添加到文本框中以便丢失焦点事件...

以下是如何：

 myElement.GotFocus + = {sender，eventArgs} = < span class =code-keyword>>  {
 UIElement senderElement =（UIElement）sender; 
 DoSomethingOnChangeOfTheFocusState（senderElement.IsFocused）;  //  如果获得焦点，IsFocused将为true，如果丢失则为false  
}; 

请注意，事件名称GotFocus有点误导。它实际上涵盖了获得和失去焦点。与事件相同 UIElement.GotKeyboardFocus 和 UIElement.PreviewGotKeyboardFocus ：

http://msdn.microsoft.com/en-us /library/system.windows.uielement.gotfocus%28v=vs.110%29.aspx [ ^ ]，

http://msdn.microsoft.com/en-us/library/system.windows .uielement.gotkeyboardfocus％28v = vs.110％29.aspx [ ^ ]，

HTTP：//msdn.mi crosoft.com/en-us/library/system.windows.uielement.previewgotkeyboardfocus%28v=vs.110%29.aspx [ ^ ]。



可选方法是覆盖相应的虚拟方法，效果相同：

http://msdn.microsoft.com/en-us/library/system.windows.uielement.ongotfocus（v = vs.110）的.aspx [ ^ ]，

http://msdn.microsoft.com/en-us/library/system.windows.uielement.ongotkeyboardfocus(v = vs.110）.aspx [ ^ ]，

http://msdn.microsoft.com/en-us/library/system .windows.uielement.onpreviewgotkeyboardfocus（v = vs.110）.aspx [ ^ ]。

-SA

Hello,
I am having a text box in wpf c# window application. I am creating it in c# dynamically in Data grid.I have attached a event handler to that text box.But problem is that when control is loaded into it the text box event is being called infinitely ...Complete code is being done in c# only... I am not using xaml ... every text box is being created dynamically.... Note: the text box is present in Data Grid... Please help me out yar...

private void txtUnitCount_Changed(object Sender, TextChangedEventArgs e)
            {
          try
          {
              int index = 0;
              int rowIndex = -1;
              TextBox txt = Sender as TextBox;
              int Units = Convert.ToInt32(txt.Text);

              for (index = 1; index < dsBillingDetails.Tables.Count; index++)
               {
                DataRowCollection rowCol = dsBillingDetails.Tables[index].Rows;

               DataRow[] DataRows = dsBillingDetails.Tables[index].Select(find);
                  if (DataRows.Count() > 0)
                 {
                    DataRow foundRow = DataRows[0];

                     rowIndex = rowCol.IndexOf(foundRow);
                     if (rowIndex != -1)
                      {

                        //This line is causing problem i.e below line
                        dsBillingDetails.Tables[index].AcceptChanges();

                       }

                      break;
                      }
                  }


          }
          catch (Exception ex)
          {
          }
      }

解决方案

Please see my questions and clarify accordingly. For now, I'll answer to one of your follow-up questions:

jing111 wrote:

…let me know how to add handler to a text box for lost focus event…

Here is how:

myElement.GotFocus += {sender, eventArgs} => {
    UIElement senderElement = (UIElement)sender;
    DoSomethingOnChangeOfTheFocusState(senderElement.IsFocused); // IsFocused will be true if got focus, false if lost
};

Note that the event name "GotFocus" is somewhat misleading. It actually covers both getting and losing focus. Same thing with the events UIElement.GotKeyboardFocus and UIElement.PreviewGotKeyboardFocus:
http://msdn.microsoft.com/en-us/library/system.windows.uielement.gotfocus%28v=vs.110%29.aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.uielement.gotkeyboardfocus%28v=vs.110%29.aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.uielement.previewgotkeyboardfocus%28v=vs.110%29.aspx[^].

The optional approach is to override corresponding virtual methods, with the same effect:
http://msdn.microsoft.com/en-us/library/system.windows.uielement.ongotfocus(v=vs.110).aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.uielement.ongotkeyboardfocus(v=vs.110).aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.uielement.onpreviewgotkeyboardfocus(v=vs.110).aspx[^].

—SA

这篇关于WAPF更改事件中的TextBox更改事件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！