用委托传值

来源：互联网发布：xboxone安卓软件编辑：程序博客网时间：2024/06/05 15:51

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace delegateSend{    public class WarnEventArgs : EventArgs    {        private string _text = String.Empty;        public string Text        {            get { return _text; }            set { _text = value; }        }    }}

Form2给Form1传参数
Form2上放一个Textbox用于设置要传给Form1的参数，button2将参数放到WarnEventArgs的对象e中
Form1上放一个lable用于显示Form2传来的参数，button2将参数从WarnEventArgs的对象e中取出

Form1的代码如下：

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;namespace delegateSend{    public delegate void WarnDelegate(WarnEventArgs e);    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        public  void Alarm(WarnEventArgs e)        {            string tem = e.Text;            label1.Text = tem.ToString();        }        private void button1_Click(object sender, EventArgs e)        {            Form2 f2 = new Form2();            f2.Show();            f2.WarnEvent += new WarnDelegate(Alarm);        }    }}

Form2代码如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace delegateSend
{
    public partial class Form2 : Form
    {
        public event WarnDelegate WarnEvent;

        public Form2()
        {
            InitializeComponent();
        }

        public void OnWarnEvent(WarnEventArgs e)
        {
            if (WarnEvent != null)
            {
                WarnEvent(e);
            }
        }

        public void Warn(string x)
        {
            WarnEventArgs e = new WarnEventArgs();
            e.Text = x;
            OnWarnEvent(e);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Warn(this.textBox1.Text);
        }
    }
}