如果我希望dgv1(datagridview)的值显示在不同的表单上，该怎么办

Question

Form1

namespace erpmam
{
public partial class Form1 : Form
{
MySqlDB mySqlDB;
SqlDataAdapter adpt;
DataTable dt;
SqlConnection con;
public void showdata()
{
adpt = new SqlDataAdapter("select deptmt_id, deptmt_name, deptmt_seq, reg_ymdtms, mod_ymdtms from sys_department;",con);
dt = new DataTable();
adpt.Fill(dt);
dgv1.DataSource = dt;
}
public Form1()
{
InitializeComponent();
}
public void Form1_Load(object sender, EventArgs e)
{
mySqlDB = new MySqlDB("server=······");
}
private SqlDataAdapter MySqlDataAdapter(string v, MySqlConnection con)
{
throw new NotImplementedException();
}
public void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
}
private void BTN_INSERT_Click(object sender, EventArgs e)
{
Form2 form2 = new Form2();
form2.ShowDialog();
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
string sql = "";
sql += " select";
sql += " deptmt_id, deptmt_name, deptmt_seq, reg_ymdtms, mod_ymdtms";
sql += " from sys_department";
sql += " where deptmt_id like '%" + textBox1.Text.Trim() + "%'";
DataTable dt = mySqlDB.ExecuteReader(sql, mySqlDB.DBConnection());
dgv1.SuspendLayout();
dgv1.Rows.Clear();
for (int idx = 0; idx < dt.Rows.Count; idx++)
{
DataRow r = dt.Rows[idx];
dgv1.Rows.Add(1);
dgv1[0, idx].Value = r["deptmt_id"].ToString().Trim();
dgv1[1, idx].Value = r["deptmt_name"].ToString().Trim();
dgv1[2, idx].Value = r["deptmt_seq"].ToString().Trim();
dgv1[3, idx].Value = r["reg_ymdtms"].ToString().Trim();
dgv1[4, idx].Value = r["mod_ymdtms"].ToString().Trim();
}
dgv1.ResumeLayout();
}
private void textBox2_TextChanged(object sender, EventArgs e)
{
string sql = "";
sql += " select";
sql += "    deptmt_id, deptmt_name, deptmt_seq, reg_ymdtms, mod_ymdtms";
sql += " from sys_department";
sql += "   where deptmt_name like '%" + textBox2.Text.Trim() + "%'";
DataTable dt = mySqlDB.ExecuteReader(sql, mySqlDB.DBConnection());
dgv1.SuspendLayout();
dgv1.Rows.Clear();
for (int idx = 0; idx < dt.Rows.Count; idx++)
{
DataRow r = dt.Rows[idx];
dgv1.Rows.Add(1);
dgv1[0, idx].Value = r["deptmt_id"].ToString().Trim();
dgv1[1, idx].Value = r["deptmt_name"].ToString().Trim();
dgv1[2, idx].Value = r["deptmt_seq"].ToString().Trim();
dgv1[3, idx].Value = r["reg_ymdtms"].ToString().Trim();
dgv1[4, idx].Value = r["mod_ymdtms"].ToString().Trim();
}
dgv1.ResumeLayout();
}
private void dgv1_CellClick(object sender, DataGridViewCellEventArgs e)
{
Form3 Form3 = new Form3();
Form3.ShowDialog();
}
}
}

Form2

namespace erpmam
{
public partial class Form2 : Form
{
MySqlConnection connection = new MySqlConnection("datasource =······");
MySqlCommand command;
public Form2()
{
InitializeComponent();
}
public void executeMyQuery(string query)
{
try
{
openConnection();
command = new MySqlCommand(query, connection);
if (command.ExecuteNonQuery() == 1)
{
MessageBox.Show("Query Executed");
}
else
{
MessageBox.Show("Query Not Executed");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
closeConnection();
}
}
public void openConnection()
{
if (connection.State == ConnectionState.Closed)
{
connection.Open();
}
}
public void closeConnection()
{
if (connection.State == ConnectionState.Open)
{
connection.Close();
}
}
private void button1_Click(object sender, EventArgs e)
{
string insertQuery = "INSERT INTO sys_department(DEPTMT_ID, DEPTMT_NAME, DEPTMT_SEQ, REG_YMDTMS) VALUES(" + textBox1.Text + ',' + textBox2.Text + ','+ textBox3.Text + ','+ "NOW()" +")";
connection.Open();
MySqlCommand command = new MySqlCommand(insertQuery, connection);
try
{
if (command.ExecuteNonQuery() == 1)
{
MessageBox.Show("adding normally");
}
else
{
MessageBox.Show("error");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
connection.Close();
this.Close();
}
private void button2_Click(object sender, EventArgs e)
{
this.Close();
}
}
}

Form3

namespace erpmam
{
public partial class Form3 : Form
{
MySqlConnection connection = new MySqlConnection("datasource = localhost; port = 3306; Initial Catalog = 'erp'; username = root; password=610822");
MySqlCommand command;
public Form3()
{
InitializeComponent();
}
public void executeMyQuery(string query)
{
try
{
openConnection();
command = new MySqlCommand(query, connection);
if (command.ExecuteNonQuery() == 1)
{
MessageBox.Show("Query Executed");
}
else
{
MessageBox.Show("Query Not Executed");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
closeConnection();
}
}        public void openConnection()
{
if (connection.State == ConnectionState.Closed)
{
connection.Open();
}
}
public void closeConnection()
{
if (connection.State == ConnectionState.Open)
{
connection.Close();
}
}
private void btn_update_Click(object sender, EventArgs e)
{
string updateQuery = " UPDATE sys_department"; 
updateQuery +=       " SET DEPTMT_NAME = '" + textBox2.Text + "', DEPTMT_SEQ = '" + textBox3.Text + "', mod_ymdtms = NOW()";
updateQuery +=       " where DEPTMT_ID = '" + textBox1.Text + "'";
connection.Open();
MySqlCommand command = new MySqlCommand(updateQuery, connection);
try
{
if (command.ExecuteNonQuery() == 1)
{
MessageBox.Show("changed normally");
}
else
{
MessageBox.Show("error");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
connection.Close();
this.Close();
}
private void btn_delete_Click(object sender, EventArgs e)
{
string deleteQuery = " DELETE from sys_department"; 
deleteQuery +=       " where DEPTMT_ID = '" + textBox1.Text + "' or DEPTMT_NAME = '" + textBox2.Text + "' or DEPTMT_SEQ = '" + textBox3.Text + "'" ;
connection.Open();
MySqlCommand command = new MySqlCommand(deleteQuery, connection);
try
{
if (command.ExecuteNonQuery() == 1)
{
MessageBox.Show("adding normally");
}
else
{
MessageBox.Show("error");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
connection.Close();
this.Close();
}
private void btn_cancel_Click(object sender, EventArgs e)
{
this.Close();
}
} 
}

Answer 1

只需创建Datatable的全局变量即可将其用作数据源，并且可以在Forms中的任何位置使用它

这是GLobal级

//make sure to import this System.Data
using System.Data;
class Global
{
private static DataTable source;
public static DataTable Source
{
get
{
// Reads are usually simple
return source;
}
set
{
// You can add logic here for race conditions,
// or other measurements
source = value;
}
}
}

在你的第一个形式

string connectString = "datasource=xxxx;port=3306;username=xxxx;password=;database=xxxxx;";
MySqlConnection conn;
MySqlCommand comm;
MySqlDataReader read;
MySqlDataAdapter adapter;
Global mySource;
void getData() {
string query = "Select * from tableName";
conn = new MySqlConnection(connectString);
conn.Open();
comm = new MySqlCommand(query, conn);
adapter = new MySqlDataAdapter(query, conn);
DataSet ds = new DataSet();
adapter.Fill(ds);

//setting up
Global.Source = ds.Tables[0];
dataGridView1.DataSource = ds.Tables[0];
conn.Close();
}

在您的第二个表单

public Form2()
{
InitializeComponent();
dataGridView1.DataSource = Global.Source;
}

Answer 2

只需在form3类中创建静态方法，并接受DataGridView类型中的一个参数，然后从form1调用该方法，并在填充行后传递dg1，就可以从该静态方法访问它了。。。

private void dgv1_CellClick(object sender, DataGridViewCellEventArgs e) {
Form3 Form3 = new Form3();
Form3.staticMethodToPassDGVBetweenTwoForms(dgv1);
Form3.ShowDialog();
}
namespace erpmam {
public partial class Form3 : Form {
public Form3() {
initializeComponent();
}
public static void staticMethodToPassDGVBetweenTwoForms(DataGridView dgv1){
//do anything with dg1 now
}
}