一种窗体间传值简单方法

上图所示的窗体传值示例，在windows应用程序中经常都会碰到，以前是想办法将form1对象传给form2，然后在form2中在适当的时机调用form1对象上的控件并设置值：

Form1.cs：

using System;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        /// <summary>
        /// 新增属性,设置textBox1的文本,供Form2调用
        /// </summary>
        public string Value
        {
            set { textBox1.Text = value; }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            (new Form2()).Show(this);//Form1传给Form2
        }
    }
}

Form2.cs：

using System;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }

        /// <summary>
        /// 双击选择
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void listBox1_DoubleClick(object sender, EventArgs e)
        {
            Form frm = this.Owner;
            if (frm is Form1)
                ((Form1)frm).Value = listBox1.SelectedItem.ToString();

            this.Close();
        }
    }
}

今天在一个项目中发现了另一种方法，更为简便：

Form1.cs：

using System;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Form2 frm = new Form2();
            textBox1.Text = frm.GetValue();
        }
    }
}

 

Form2.cs：

using System;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }

        /// <summary>
        /// 获取文本框中的值
        /// </summary>
        /// <returns></returns>
        public string GetValue()
        {
            this.ShowDialog();//一定不能用this.Show()

            //下边代码得this.Close()后才能继续执行
            if (listBox1.SelectedIndex != -1)
                return listBox1.SelectedItem.ToString();
            else
                return string.Empty;
        }

        /// <summary>
        /// 双击选择
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void listBox1_DoubleClick(object sender, EventArgs e)
        {
            this.Close();
        }
    }
}