WPF如何动态创建文本框并在按钮单击时找到文本框？

Question

我使用以下代码创建动态TextBox和Button动态:

Button btnClickMe = new Button();
btnClickMe.Content = "Click Me";
btnClickMe.Name = "btnClickMe";
btnClickMe.Click += new RoutedEventHandler(this.CallMeClick);

someStackPanel.Childern.Add(btnClickMe);

TextBox txtNumber = new TextBox();
txtNumber.Name = "txtNumber";
txtNumber.Text = "1776";

someStackPanel.Childern.Add(txtNumber);

我联系了Click Me按钮的点击事件.单击我按钮甚至被正确触发.但是我找不到TextBox我动态输入的内容.

这是我点击我的活动:

protected void ClickMeClick(object sender, RoutedEventArgs e)
{
    // Find the phone number
    TextBox txtNumber = this.someStackPanel.FindName("txtNumber") as TextBox;

    if (txtNumber != null)
    {
        string message = string.Format("The number is {0}", txtNumber.Text);

        MessageBox.Show(message);    
    }
    else
    {
        MessageBox.Show("Textbox is null");
    }
}

我该TextBox txtNumber怎么找到？

Answer 1

Josh G有修复此代码的线索:使用RegisterName().

这里有三个好处:

1. 不使用成员变量来保存对动态创建的TextBox的引用.
2. 编译.

3. 完整的代码.

   using System;
   using System.Windows;
   using System.Windows.Controls;
   
   namespace AddControlsDynamically
   {
       public partial class Window1 : Window
       {
           public void Window_Loaded(object sender, RoutedEventArgs e)
           {
               GenerateControls();
           }
           public void GenerateControls()
           {
               Button btnClickMe = new Button();
               btnClickMe.Content = "Click Me";
               btnClickMe.Name = "btnClickMe";
               btnClickMe.Click += new RoutedEventHandler(this.CallMeClick);
               someStackPanel.Children.Add(btnClickMe);
               TextBox txtNumber = new TextBox();
               txtNumber.Name = "txtNumber";
               txtNumber.Text = "1776";
               someStackPanel.Children.Add(txtNumber);
               someStackPanel.RegisterName(txtNumber.Name, txtNumber);
           }
           protected void CallMeClick(object sender, RoutedEventArgs e)
           {
               TextBox txtNumber = (TextBox) this.someStackPanel.FindName("txtNumber");
               string message = string.Format("The number is {0}", txtNumber.Text);
               MessageBox.Show(message);
           }
       }
   }
   

Answer 2

另一种方法是将关联设置TextBox为Button Tag实例化时.

btnClickMe.Tag = txtNumber;

这样您就可以在事件处理程序中将其检索回来.

protected void ClickMeClick(object sender, RoutedEventArgs e)
{
    Button btnClickMe = sender as Button;
    if (btnClickMe != null)
    {
        TextBox txtNumber = btnClickMe.Tag as TextBox;
        // ...
    }
}

Answer 3

您可以通过注册文本框的名称来使原始点击处理程序正常工作：

someStackPanel.RegisterName(txtNumber.Name, txtNumber);

然后，这将允许您在StackPanel上调用FindName并找到TextBox。