窗体相互传值

属性法：

Form2：

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 窗体属性传值
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        private string _str;
        public string str
        {
            set { _str = value; }
            get { return _str; }

        }
        private void Form2_Load(object sender, EventArgs e)
        {
            textBox1.Text = _str;
        }
    }
}

Form1

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 窗体属性传值
{
    public partial class Form1 : Form
    {
        public  Form1()
        {
            InitializeComponent();
        }
      
        private void button1_Click(object sender, EventArgs e)
        {
            Form2 f2 = new Form2();
            f2.str = textBox1.Text;
            f2.ShowDialog();
           
        }
    }
}

 构造函数法：

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

namespace 窗体间通迅
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Form2 frm = new Form2(this.textBox1);
            frm.Show();

        }
    }
}

///Form2.cs  the form contains a textbox and a button
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace 窗体间通迅
{
    public partial class Form2 : Form
    {
        private delegate void dg();

        /// <summary>
        /// 让其与窗体1的TextBox1同一个引用。
        /// </summary>
        private TextBox textBox12;

        public Form2()
        {
            InitializeComponent();
        }

        public Form2(TextBox txtBox)
        {
            InitializeComponent();
            textBox1.Text = txtBox.Text; ;
            this.textBox12 = txtBox;
           
        }

        private void button1_Click(object sender, EventArgs e)
        {
            textBox12 .Text  = textBox1.Text;
            this.Close();
           
        }
    }
}

构造函数传值

Form2

public Picture(string f,string picfile,string note)
        {
            InitializeComponent();
            this._f = f;
            this._picfile=picfile;
            this._note = note;
        }
        private string _f;
        private string _picfile;
        private string _note;

Form2

            int foodid = int.Parse(dataGridView1.Rows[index].Cells["foodid"].Value.ToString());
            string picfile = dataGridView1.Rows[index].Cells["picturefile"].Value.ToString();
            string note = dataGridView1.Rows[index].Cells["note"].Value.ToString();
            Picture f = new Picture(foodid.ToString(),picfile,note);
            f.Show();