在表单之间传递表单值 [英] passing form values between forms

问题描述

我有两种形式；表格1和表格2.

1.我单击表格一中的按钮以打开表格二.
2.我在形式二的文本框中输入值.
3.我单击形式二中的保存.
4.值以格式一显示在文本框中.

我该如何实施?
在此先谢谢您.

I have two forms; form 1 and form 2.

1. I click on a button in form one to open form two.
2. I enter value into a textbox in form two.
3. I click on save in form two.
4. Value is displayed in textbox in form one.

How can I implement this?
Thanks in advance.

推荐答案

请不要执行АslamIqbal或Manivannan Shan所建议的操作:如果不建议将表单上的任何控件公开，则不要这样做.原因很简单:这样做时，您会将两个表单的设计联系在一起-无法更改form1，除非检查它不会影响form2.您也不能重用form3中的form2，因为它可能没有相同的布局或用途.

相反，有两种方法可以做到:

1)像对待OpenFileDialog一样对待form2:将其显示，等待用户按OK，然后关闭form2并在form1中获取值.这很容易:设置一个公共属性，该属性以与OpenFileDialog提供FileName
相同的方式返回值.

Please, do not do what Аslam Iqbal or Manivannan Shan are recommending: it if a bad idea to make any controls on your form public. The reason is simple: when you do that you ties the design of the two forms together - you cannot change form1 without checking that it will not affect form2. You also cannot re-use form2 from form3 because it may not have the same layout or purpose.

Instead, there are two ways to do it:

1) Treat form2 like you would a OpenFileDialog: Show it, wait for the user to press OK and the close form2 and fetch the value in form1. That''s easy: Set up a public property which returns the value(s) in the same way the OpenFileDialog supplies FileName

public string Value
   {
   get { return textboxUserInputTo.Text; }
   set { textboxUserInputTo.Text = value; }

然后使用
显示您的表单

Then display your form with

form2 f2 = new form2();
if (f2.ShowDialog() == DialogResult.OK)
   {
   string s = f2.Value;
   ...
   }

2)在form2中设置一个事件，说我对你有价值".

2) Set up an event in form2 which says "I have a value for you".

public event EventHandler Changed;

protected virtual void OnChanged(EventArgs e)
   {
   EventHandler eh = Changed;
   if (eh != null)
      {
      eh(this, e);
      }
   }

private void DoSomethingToChangeData()
   {
   OnChanged(null);
   }

Form1然后订阅该事件.

Form1 then subscribes to the event.

private void ShowChildForm()
    {
    // Link in his event so if it changes, we detect it.
    form2 f2 = new form2();
    f2.Change += new form2.ChangeHandler(Changed);
    f2.Show();
    }
//
// Fired when the file is changed at a lower level.
//
private void Changed(object sender, EventArgs e)
    {
    form2 f2 = sender as form2;
    string s = f2.Value;
    }

在from2中执行以下操作...(将Form1实例传递给form2构造函数并进行全局分配.当form2按钮单击将值分配给form1文本框时)

注意:将文本框控件访问说明符设为public.

In from2 do the following...(Pass Form1 instance to form2 constuctor and to assign in global.when form2 button click assign value to form1 text box)

Note:Make the textbox control access specifier to public.

public partial class Form2 : Form
   {
       Form1 frm1 = null;
       public Form2(Form form1)
       {
           InitializeComponent();
           frm1 = (Form1)form1;
       }
       private void button1_Click(object sender, EventArgs e)
       {
           frm1.textBox1.Text = "your value";
       }
   }

同样明智的是，在Form1中

Like wise, in Form1

private void button1_Click(object sender, EventArgs e)
        {
            Form2 frm2 = new Form2(this);
            frm2.Show();
        }

请参见

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