private void Form1_Load(object sender, EventArgs e)
        {
            foreach (Control control in this.userControl11.Controls)
            {
                if (control is DataGridView)
                {
                    DataGridView dgv = (DataGridView)control;
                    dgv.CellContentDoubleClick += new DataGridViewCellEventHandler(dgv_CellContentDoubleClick);
                }
            }
        }

        void dgv_CellContentDoubleClick(object sender, DataGridViewCellEventArgs e)
        {
            //这样双击事件对外提供了，处理内容略
        }

//在另一个窗口中修改当前选定的DataGrid的行

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
//主窗体代码
namespace Zhzuo
{
    public class Form1 : System.Windows.Forms.Form
    {
        private System.Windows.Forms.DataGrid dataGrid1;
        private DataSet ds;
        private System.Windows.Forms.Button button1;
        /// <summary>
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.Container components = null;

        public Form1()
        {
            InitializeComponent();
            ds = new DataSet("MyDataSet");
            InitData(ds);
            this.dataGrid1.DataSource = this.ds;
            this.dataGrid1.DataMember = this.ds.Tables[0].TableName;
        }

        /// <summary>
        /// 清理所有正在使用的资源。
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        #region Windows 窗体设计器生成的代码
        /// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {
            this.dataGrid1 = new System.Windows.Forms.DataGrid();
            this.button1 = new System.Windows.Forms.Button();
            ((System.ComponentModel.ISupportInitialize)(this.dataGrid1)).BeginInit();
            this.SuspendLayout();
            // 
            // dataGrid1
            // 
            this.dataGrid1.DataMember = "";
            this.dataGrid1.HeaderForeColor = System.Drawing.SystemColors.ControlText;
            this.dataGrid1.Location = new System.Drawing.Point(16, 20);
            this.dataGrid1.Name = "dataGrid1";
            this.dataGrid1.Size = new System.Drawing.Size(340, 160);
            this.dataGrid1.TabIndex = 0;
            this.dataGrid1.DoubleClick += new System.EventHandler(this.dataGrid1_DoubleClick);
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(264, 196);
            this.button1.Name = "button1";
            this.button1.TabIndex = 1;
            this.button1.Text = "修改";
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // Form1
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
            this.ClientSize = new System.Drawing.Size(372, 229);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.dataGrid1);
            this.Name = "Form1";
            this.Text = "Form1";
            ((System.ComponentModel.ISupportInitialize)(this.dataGrid1)).EndInit();
            this.ResumeLayout(false);

        }
        #endregion

        private void InitData(DataSet ds)
        {
            DataTable dt = new DataTable("TabeHost");
            DataColumn dc = new DataColumn("IpAddress",typeof(string));
            dt.Columns.Add(dc);
            dc = new DataColumn("UserName",typeof(string));
            dt.Columns.Add(dc);
            dc = new DataColumn("Password",typeof(string));
            dt.Columns.Add(dc);
            ds.Tables.Add(dt);
            
            DataRow dr = dt.NewRow();
            dr["IpAddress"] = "192.192.132.229";
            dr["UserName"] = "zhzuo";
            dr["Password"] = "zhengzuo";
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr["IpAddress"] = "192.192.132.230";
            dr["UserName"] = "11";
            dr["Password"] = "12";
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr["IpAddress"] = "192.192.132.231";
            dr["UserName"] = "123";
            dr["Password"] = "12";
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr["IpAddress"] = "192.192.132.232";
            dr["UserName"] = "22";
            dr["Password"] = "788";
            dt.Rows.Add(dr);
        }

        private void button1_Click(object sender, System.EventArgs e)
        {
            DataRowView drv = (DataRowView)this.BindingContext[this.ds,this.ds.Tables[0].TableName].Current;
            Form2 form2 = new Form2(drv);
            form2.ShowDialog();

        }
        private void dataGrid1_DoubleClick(object sender, System.EventArgs e)
        {
            button1_Click(button1,EventArgs.Empty);
        }
    }
}
//子窗体代码
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace Zhzuo
{
    /// <summary>
    /// Form2 的摘要说明。
    /// </summary>
    public class Form2 : System.Windows.Forms.Form
    {
        private System.Windows.Forms.TextBox textBox1;
        private System.Windows.Forms.TextBox textBox2;
        private System.Windows.Forms.TextBox textBox3;
        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.Button button2;
        private DataRowView drv;
        /// <summary>
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.Container components = null;

        public Form2(DataRowView dr)
        {
            InitializeComponent();
            this.drv = dr;
            this.textBox1.Text = (string)drv["IpAddress"];
            this.textBox2.Text = (string)drv["UserName"];
            this.textBox3.Text = (string)drv["Password"];
        }

        /// <summary>
        /// 清理所有正在使用的资源。
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if(components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        #region Windows 窗体设计器生成的代码
        /// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {
            this.textBox1 = new System.Windows.Forms.TextBox();
            this.textBox2 = new System.Windows.Forms.TextBox();
            this.textBox3 = new System.Windows.Forms.TextBox();
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // textBox1
            // 
            this.textBox1.Location = new System.Drawing.Point(28, 16);
            this.textBox1.Name = "textBox1";
            this.textBox1.TabIndex = 3;
            this.textBox1.Text = "textBox1";
            // 
            // textBox2
            // 
            this.textBox2.Location = new System.Drawing.Point(28, 56);
            this.textBox2.Name = "textBox2";
            this.textBox2.TabIndex = 4;
            this.textBox2.Text = "textBox2";
            // 
            // textBox3
            // 
            this.textBox3.Location = new System.Drawing.Point(28, 92);
            this.textBox3.Name = "textBox3";
            this.textBox3.TabIndex = 5;
            this.textBox3.Text = "textBox3";
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(152, 152);
            this.button1.Name = "button1";
            this.button1.TabIndex = 6;
            this.button1.Text = "保存";
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // button2
            // 
            this.button2.Location = new System.Drawing.Point(236, 152);
            this.button2.Name = "button2";
            this.button2.TabIndex = 7;
            this.button2.Text = "退出";
            this.button2.Click += new System.EventHandler(this.button2_Click);
            // 
            // Form2
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
            this.ClientSize = new System.Drawing.Size(324, 201);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.textBox3);
            this.Controls.Add(this.textBox2);
            this.Controls.Add(this.textBox1);
            this.Name = "Form2";
            this.Text = "Form2";
            this.ResumeLayout(false);

        }
        #endregion

        private void button1_Click(object sender, System.EventArgs e)
        {
            drv["IpAddress"] = this.textBox1.Text;
            drv["UserName"] = this.textBox2.Text;
            drv["Password"] = this.textBox3.Text;
        }

        private void button2_Click(object sender, System.EventArgs e)
        {
            this.Close();
        }
    }
}

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

namespace WindowsApplication4
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            SqlConnection sqlcon = Connection();
            sqlcon.Open();
            this.comboBox1.DropDownStyle = ComboBoxStyle.DropDownList;
            string strCmd = "SELECT DISTINCT PROVINCE FROM PROVINCECITYTAB ";
            SqlDataAdapter sqladp = new SqlDataAdapter(strCmd, sqlcon);
            DataSet ds = new DataSet();
            sqladp.Fill(ds, "provinceTab");
            for (int i = 0; i < ds.Tables["provinceTab"].Rows.Count; i++)
            {
                string province = ds.Tables["provinceTab"].Rows[i]["province"].ToString();
                this.comboBox1.Items.Add(province);
            }
            sqlcon.Close();
        }

        private SqlConnection Connection()
        {
            string strCon = "data source=MANNA;initial catalog=manna;integrated security=true";
            SqlConnection sqlcon = new SqlConnection(strCon );
            return sqlcon;
        }

        private void BindDataGridView()
        {
            SqlConnection sqlcon = Connection();
            sqlcon.Open();
            String strProvince=this.comboBox1 .Text ;
            string str = "SELECT CITY FROM PROVINCECITYTAB WHERE PROVINCE='" + strProvince + "'";
            SqlDataAdapter sqladp = new SqlDataAdapter(str, sqlcon);
            DataSet ds = new DataSet();
            sqladp.Fill(ds, "cityTab");
            this.dataGridView1.DataSource = ds.Tables["cityTab"];
            sqlcon.Close();
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            BindDataGridView();
        }

        private void dataGridView1_CellContentDoubleClick(object sender, DataGridViewCellEventArgs e)
        {
            SqlConnection sqlcon = Connection();
            sqlcon.Open();
            String strProvince = this.comboBox1.Text;
            string str = "SELECT CITY FROM PROVINCECITYTAB WHERE PROVINCE='" + strProvince + "'";
            SqlDataAdapter sqladp = new SqlDataAdapter(str, sqlcon);
            DataSet ds = new DataSet();
            sqladp.Fill(ds, "cityTab");
            this.dataGridView1.DataSource = ds.Tables["cityTab"];
            sqlcon.Close();

            int i = e.RowIndex;
            int j = e.ColumnIndex;
            string city = ds.Tables["cityTab"].Rows[i][j].ToString();
            this.textBox1.Text = city;
        }
    }
}