c# - 将 MDI 父级的字符串传递给子级的模态对话框

Question

如何将字符串从 MDI 父级传递给子级的模态对话框？

MDI父代码打开子：

Form1 f1 = new Form1();
f1.MdiParent = this;
f1.Show();

Form1 代码打开模态对话框

Form2 f2= new Form2();
f2.ShowDialog();

Answer 1

只需通过使用每个级别的属性来传递它：

//Form1 needs a property you can access
public class Form1
{
    private String _myString = null;
    public String MyString { get { return _myString; } }

    //change the constructor to take a String input
    public Form1(String InputString)
    {
        _myString = InputString;
    }
    //...and the rest of the class as you have it now
}

public class Form2
{
    private String _myString = null;
    public String MyString { get { return _myString; } }

    //same constructor needs...
    public Form2(String InputString)
    {
        _myString = InputString;
    }
}

最终，您的电话变成：

String strToPassAlong = "This is the string";

Form1 f1 = new Form1(strToPassAlong);
f1.MdiParent = this;
f1.Show();

Form2 f2= new Form2(f1.MyString);  //or this.MyString, if Form2 is constructed by Form1's code
f2.ShowDialog();

现在，沿途的每个表单都有一个您传递的字符串的副本。

Answer 2

如果您总是将表单用作模态表单，则可以使用与此类似的模式。

    class FormResult
    {
      public DialogResult dr {get; private set;}
      public string LastName {get; private set;}
      public string FirstName {get; private set;}
    }

    class MyForm : whatever
    {
      static public FormResult Exec(string parm1, string parm2)
{
      var result = new FormResult();
      var me = new MyForm();
      me.parm1 = parm1;
      me.parm2 = parm2;
      result.dr = me.ShowDialog();
      if (result.dr == DialogResult.OK)
      {
        result.LastName = me.LastName;
        result.FirstName = me.FirstName;
      }
      me.Close(); // should use try/finally or using clause
      return result;
    }
}

... rest of MyForm

此模式隔离了您使用表单的“私有”数据的方式，并且如果您决定添加 mors 返回值，则可以轻松扩展。如果您有更多的输入参数，您可以将它们捆绑到一个类中并将该类的实例传递给 Exec 方法