form2调用form1自定义函数的问题

[fjtxwd]

form1有个datagridview，一个button，点击弹出form2，然后把form2中textbox中数据插入到数据表，关闭form2，更新form1的datagridview。
下面的代码datagridview不会更新，要怎么改？

//form1
private void Form1_Load(object sender, EventArgs e)
        {
            loadfromtfctable();
        }

public void loadfromtfctable()
        {
            dataGridView1.DataSource =0;
            string connstr = "Data Source=MICROSOF-602800\\SQLEXPRESS;Initial Catalog=tfc;Integrated Security=True";
            string commstr = "select * from tfctable";
            SqlConnection conn = new SqlConnection(connstr);
            SqlCommand comm = new SqlCommand(commstr, conn);
            conn.Open();
            SqlDataAdapter da = new SqlDataAdapter(comm);
            DataTable dt = new DataTable();
            da.Fill(dt);
            dataGridView1.DataSource = dt;
            conn.Close();
        }

//按钮事件
private void addANodeToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Form2 form2 = new Form2();
            form2.ShowDialog();
        }



//form2
Form1 form1 = new Form1();

//按钮添加数据
private void button1_Click(object sender, EventArgs e)
        {
            string connstr = "Data Source=MICROSOF-602800\\SQLEXPRESS;Initial Catalog=tfc;Integrated Security=True";
            string commstr = "insert into tfctable(node,parent) values('"+textBox1.Text+"','--')";
            SqlConnection conn = new SqlConnection(connstr);
            SqlCommand comm = new SqlCommand(commstr, conn);
            conn.Open();
            comm.ExecuteNonQuery();
            conn.Close();
            form1.loadfromtfctable();      //好像是这里没什么用

[szzzp110]

插入后看数据库中数据表有无更新？
代码貌似没问题，我去试验下

[pmallen]

form1.loadfromtfctable()这个form1对象已经不原来的Form1_Load上的那个from1对象了
你可以在新建Form2 form2 = new Form2()时,把this对象传给它,这是一种,我没试过;
第二种方法:你可以事件来实现的.

[syfsz]

//按钮事件
private void addANodeToolStripMenuItem_Click(object sender, EventArgs e)
{
Form2 form2 = new Form2();
Form2.form1 = this;
form2.ShowDialog();
}



//form2
public Form1 form1 =null;

//按钮添加数据

[bugers]

LZ的思路是VB 的写法，C# 要复杂 一些 ，据MSDN说这样是为了安全

[syfsz]

private void addANodeToolStripMenuItem_Click(object sender, EventArgs e)
{
Form2 form2 = new Form2();
if (form2.ShowDialog()==DialogResult.Ok)
{
Try
{
string connstr = "Data Source=MICROSOF-602800\\SQLEXPRESS;Initial Catalog=tfc;Integrated Security=True";
string commstr = "insert into tfctable(node,parent) values('"+form2.ReturnValue+"','--')";
SqlConnection conn = new SqlConnection(connstr);
SqlCommand comm = new SqlCommand(commstr, conn);
conn.Open();
comm.ExecuteNonQuery();
conn.Close();
this.loadfromtfctable();
}
catch
{
MessageBox.Show("更新失败");
}
}
}


// form2

public string ReturnValue
{
get{return textBox1.Text;}
}

[szzzp110]

2楼说的对 用类可以实现的
先定于个公共类 BaseClass（好处不多说）

#region 建立数据库连接
/// <summary>
/// 建立数据库连接.
/// </summary>
/// <returns>返回SqlConnection对象</returns>
public SqlConnection getcon()
{
string M_str_sqlcon = "Data Source=(local);Database=db_SMS;User id=sha;PWD=8441213";
SqlConnection myCon = new SqlConnection(M_str_sqlcon);
return myCon;
}
#endregion

#region 执行SqlCommand命令
/// <summary>
/// 执行SqlCommand
/// </summary>
/// <param name="M_str_sqlstr">SQL语句</param>
public void getcom(string M_str_sqlstr)
{
SqlConnection sqlcon = this.getcon();
sqlcon.Open();
SqlCommand sqlcom = new SqlCommand(M_str_sqlstr, sqlcon);
sqlcom.ExecuteNonQuery();
sqlcom.Dispose();
sqlcon.Close();
sqlcon.Dispose();
}
#endregion

#region 创建DataSet对象
/// <summary>
/// 创建一个DataSet对象
/// </summary>
/// <param name="M_str_sqlstr">SQL语句</param>
/// <param name="M_str_table">表名</param>
/// <returns>返回DataSet对象</returns>
public DataSet getds(string M_str_sqlstr, string M_str_table)
{
SqlConnection sqlcon = this.getcon();
SqlDataAdapter sqlda = new SqlDataAdapter(M_str_sqlstr, sqlcon);
DataSet myds = new DataSet();
sqlda.Fill(myds, M_str_table);
return myds;
}
#endregion

Form1窗体中先定义
BaseClass.DataCon datacon = new BaseClass.DataCon();
Form1_Load()事件中
DataSet myds = datacon.getds（"select * from tfctable","tfctable"）；
dataGridView1.DataSource = mysd.table["tfctable"];
//按钮事件
private void addANodeToolStripMenuItem_Click(object sender, EventArgs e)
{
Form2 form2 = new Form2();
form2.ShowDialog();
this.close();
}





Form2窗体中先定义
BaseClass.DataCon datacon = new BaseClass.DataCon();
//按钮添加数据
private void button1_Click(object sender, EventArgs e)
{
datacom.getcom("insert into tfctable(node,parent) values('"+textBox1.Text+"','')
Form1 f1=new Form1();
f1.show();
}
定义公共类对数据库的操作（插入，更新）方便多了，