Winfrom窗体间传值

1.通过tag属性传输，tag属性是存储与空间密切相关的数据。比如登陆界面的数据传输给主界面。

子窗体                                                                        主窗体

        

定义一个类

namespace FrmLogin
{
    public class User
    {
        public string UserName { set; get; }
        public string PassWorld { set; get; }
    }
}

子窗体.cs

private void buttonLogin_Click(object sender, EventArgs e)
        {
            User user = new User();
            user.UserName = this.textBoxName.Text.Trim();
            user.PassWorld = this.textBoxPassWorld.Text;

            this.Tag = user;

            this.DialogResult = DialogResult.OK;
        }

父（主）窗体.cs

private void FormMain_Load(object sender, EventArgs e)
   {
            FormLogin frm = new FormLogin();
            if (frm.ShowDialog() == DialogResult.OK)
            {
                User user = frm.Tag as User;

                this.Text += string.Format("--欢迎您:{0}", user.UserName);

            }
            else
            {
                frm.Close();
            }
 }

2.创建一个类，相当于创建了全局共享的静态变量，然后大家都来访问这个静态变量。

全局类.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace FrmLogin
{
    public class ConText
    {
        public static User UserLogin = null;
    }
}

子窗体.cs

private void buttonLogin_Click(object sender, EventArgs e)
        {
            User user = new User();
            user.UserName = this.textBoxName.Text.Trim();
            user.PassWorld = this.textBoxPassWorld.Text;

            //this.Tag = user;

            ConText.UserLogin = user;
            this.DialogResult = DialogResult.OK;
        }

主窗体.cs

        private void FormMain_Load(object sender, EventArgs e)
        {
            FormLogin frm = new FormLogin();
            if (frm.ShowDialog() == DialogResult.OK)
            {
               // User user = frm.Tag as User;
                User user = ConText.UserLogin;

                this.Text += string.Format("--欢迎您:{0}", user.UserName);

            }
            else
            {
                frm.Close();
            }
        }

3.利用子窗体tag属性

子窗体.cs

 private void buttonLogin_Click(object sender, EventArgs e)
        {
            User user = new User();
            user.UserName = this.textBoxName.Text.Trim();
            user.PassWorld = this.textBoxPassWorld.Text;

            FormLogin main = this.Owner as FormLogin;
            if (main == null)
            {
                MessageBox.Show("LOGIN窗体没有Owner，请检查代码！！");
            }
            main.Tag = user;
            this.DialogResult = DialogResult.OK;
        }

父窗体.cs

 private void FormMain_Load(object sender, EventArgs e)
        {
            FormLogin frm = new FormLogin();
            if (frm.ShowDialog(this) == DialogResult.OK)//这儿一定要加this
            {

                User user = this.Tag as User;
                this.Text += string.Format("--欢迎您:{0}", user.UserName);

            }
            else
            {
                frm.Close();
            }
        }