如何将文本从动态生成的用户控件传输到文本框

Question

我有一个 Windows 窗体，其中有一个 button1，当单击它时，动态添加到代码中的 UserControl 是这样的：

    int c = 0;
    private void button1_Click(object sender, EventArgs e)
    {
        int v;
        v = c++;
        panel1.VerticalScroll.Value = VerticalScroll.Minimum;
        UserControl1 us = new UserControl1();
        us.Name = "us" + v;
        us.Location = new Point(50, 5 + (30 * v));
        us.Tag = btn;
        panel1.Controls.Add(us);
     }

UserControl 包含 4 个控件、2 个组合框和 2 个文本框

即combobox1、combobox2、textbox1 和textbox2

有 4 个文本框在同一个表单上

still-textbox1、still-textbox2、still-textbox3 和 still-textbox4

有button2，它会将文本传输到组合框和文本框oldcombobox1、oldcombobox2、oldtextbox1和oldtextbox2

当button1 被点击两次时，它会在表单中添加两个UserControls。 我想以以下格式传输文本

oldcombobox1.text = still-textbox1.text + "," + combobox1.text(which is dynamically generated) + "," + combobox1.text (which is dynamically generated) 等来自 UserControl 的所有 combobox1 文本（动态添加）

oldcombobox2.text = still-textbox2.text + "," + combobox2.text (which is dynamically generated) + "," + combobox2.text (which is dynamically generated) 等来自 UserControl 的所有 combobox2 文本（动态添加）

oldtextbox1.text = still-textbox3 + "," + textboox1.text (which is dynamically generated) + "," + textbox1.text (which is dynamically generated) 等来自UserControl 的所有textbox1 文本（动态添加）

表示still-textbox1.text = first 当动态 UserControl 添加 3 次时，它将包含 3 次 combobox1 然后 oldcombobox1 应包含：

first、combobox1.text、combobox1.text、combobox1.text

我已经编写了这段代码，但它不起作用

  foreach (Control ctrl in panel1.Controls)
   {
     if (ctrl is UserControl)
     {
         UserControl1 myCrl = ctrl as UserControl1;
         oldcombobox1.text = still-textbox1.text + "," + myCrl.comboBox1.Text;
         oldcombobox2.Text =still-textbox2.text + "," + myCrl.comboBox2.Text;
         oldtextbox1.Text = still-textbox3.text + "," + myCrl.textBox1.Text;
         oldtextbox2.Text.Text = still-textbox4.text + "," + myCrl.textBox2.Text;
      }
    }

Answer 1

您可以创建一个类级别的变量：

    private UserControl1 us1;
    private UserControl1 us2;

    private void button1_Click(object sender, EventArgs e)
    {
        int v;
        v = c++;
        panel1.VerticalScroll.Value = VerticalScroll.Minimum;

        if(us == null) 
        {
            //this is the first time the control is created
            us1 = new UserControl1();
            us1.Name = "us" + v;
            us1.Location = new Point(50, 5 + (30 * v));
            us1.Tag = btn;        
            panel1.Controls.Add(us1);
        }
        else if(us2 ==null)
        {
            us2 = new UserControl1();
            //whatever code you want to execute to change second one
            //you can access first control as us1.xxx
            panel1.Controls.Add(us2);

        }
        else
        {
           //3rd 4th etc...
        }


     }

Answer 2

你应该为你想要从另一个对象访问的每个字符串添加类似这样的内容UserControl1（伟大的名字顺便说一句;-)），在这种情况下是textBox1的字符串：

public String FirstTextBoxText 
{
   get { return this.textBox1.Text; }
}

然后你可以在你的 Form 类中说：

 if (ctrl is UserControl)
 {
     UserControl1 myCrl = ctrl as UserControl1;
     // ...
     oldtextbox1.Text = still-textbox3.text + "," + myCrl.FirstTextBoxText;
 }

这仍然是可怕的代码，但它会工作。

Answer 3

我会用事件来做这个。

创建一个继承自 EventArgs 的类： （我更喜欢VB，你可以翻译）

Public Class ControlEventArgs
  Inherits EventArgs

  Public Property Value1 As String = String.Empty
  Public Property Value2 As String = String.Empty
  Public Property Value3 As String = String.Empty
  Public Property Value4 As String = String.Empty

End Class

然后在你的控件中添加事件：

Public Event ValueSubmittal As EventHandler(Of ControlEventArgs)

在您的 Button2_Click 处理程序中：

RaiseEvent ValueSubmittal(me, new ControlEventArgs With {.Value1=comboBox1.Text, .Value2 = comboBox2.Text, .Value3 = textBox1.Text, .Value4 = textBox2.Text}

在您动态创建控件的表单中，您需要连接事件处理程序：

AddHandler myNewControl.ValueSubmittal, AddressOf ValueSubmittalHandler

还有ValueSubmittalHandler：

Private Sub ValueSubmittalHandler(sender as Object, e As ControlEventArgs)
  formControl1.Text = e.Value1
  formControl2.Text = e.Value2
  '  etc...
End Sub