做了很多專案，很多專案都用到子父窗體之間的傳值。。

父窗體傳入子窗體都比較簡單，而子窗體傳入父窗體因為有很多不通道的需求，所以·搞起來有點頭大。

先說父窗體傳入子窗體：

將父窗體控制元件上的值傳入子窗體的控制元件上：

Form1為父窗體

Form2為子窗體

Form1 單擊按鈕開啟Form2，Form2關閉的時候把值傳到Form1的控制元件上

程式碼：

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 WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Form2 f2 = new Form2(this.textBox1.Text);
            if (f2.ShowDialog() == DialogResult.OK)
            {
                this.textBox1.Text = f2.TextBoxValue;
                f2.Close();
            }

        }

    }
}
 

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 WindowsFormsApplication3
{
    public partial class Form2 : Form
    {
        public Form2():this(null)
        {
            
        }

        public string TextBoxValue
        {
            get { return textBox1.Text; }
            set { textBox1.Text = value; }
        }

        public Form2(string value) {
            InitializeComponent();
            TextBoxValue = value;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.DialogResult = DialogResult.OK;
        }
       
    }
}
 

對於這種情況，問你就需要使用 事件委託來完成。

----------------------------------------------------------快樂的分割線-------------------------------------------------------------

Form1程式碼：

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 WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        
        private void button2_Click(object sender, EventArgs e)
        {
            Form2 f2 = new Form2();
            f2.TextBoxChanged += new EventHandler(
                (sender1, e1) =>
                { textBox2.Text = f2.TextBoxValue; }
            );
            f2.FormClosed += new FormClosedEventHandler(
                (sender2, e2) => { f2 = null; }
            );
            f2.Show(this);
        }
    }
}
 

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 WindowsFormsApplication3
{
    public partial class Form2 : Form
    {
        public Form2():this(null)
        {
            
        }

        public string TextBoxValue
        {
            get { return textBox1.Text; }
            set { textBox1.Text = value; }
        }

        public event EventHandler TextBoxChanged;

        public Form2(string value) {
            InitializeComponent();
            TextBoxValue = value;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.DialogResult = DialogResult.OK;
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            if (TextBoxChanged != null)
            {
                TextBoxChanged(this, e);
            }
        }
    }
}

上面就是兩種子窗體傳入父窗體值的方法。