父窗体:Form1 ,有个 textbox1.text ,有个button1
子窗体:Form2 ,有个 textbox1.text ,有个button1
修改Form1 的textbox1.text ,点击Form1的 button1,弹出Form2,点击Form2 的button ,结果:Form2的 textbox1.text 的值为 Form1的textbox1.text ,修改下 Form1的textbox1.text ,再点Form2 的button ,Form2的 textbox1.text 的值与Form1的 textbox1.text 保持一致
首先在Form2中定义委托和事件:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace TestDelegate
{
public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
}
private void Form2_Load(object sender, EventArgs e)
{
}
public delegate string TransfDelegate(); //委托的方法体必须返回值为string,无参数
public event TransfDelegate TransfEvent;
private void button1_Click(object sender, EventArgs e)
{
textBox1.Text = TransfEvent();
}
}
}
然后在Form1中进行调用:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace TestDelegate
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
Form2 frm = new Form2();
//注册事件
frm.TransfEvent += GetValueEvent;
frm.Show();
}
string GetValueEvent()
{
return textBox1.Text;
}
}
}