winform子窗体向父窗体多次传值不知道怎么办，请大家帮助看一下!
子窗体向父窗体一次传值，可以实现，但现在要求多次传值不知道怎么办，请大家帮助看一下，谢谢！
子窗体代码如下：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace GiBs
{
public partial class frmPlnInfo : Form
{
public frmPlnInfo()
{
InitializeComponent();
}

public string PlntType {
get { return cmbPlnType.Text; }
set { cmbPlnType.Text = value; }
}
public string PlnCode {
get { return cmbPlnCode.Text; }
set { cmbPlnCode.Text = value; }
}

private void frmPlnInfo_Load(object sender, EventArgs e)
{

}

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


父窗体代码：窗体上有button和 datgridview 控件
private void butPln_Click(object sender, EventArgs e)
{
frmPlnInfo frmPlan = new frmPlnInfo();
frmPln.StartPosition = FormStartPosition.Manual;
frmPln.Location = new Point(700, 100);
frmPln.Show();
frmPln.ShowDialog();

if (frmPln.DialogResult == DialogResult.OK)
{
string plntype = frmPln.PlanCode;
string plncode = frmPln.PlanType;

this.dataGridView3.Rows.Add(plntype, plncode); //添加空行
this.dataGridView3.Focus();

}
else if (frmPln.DialogResult == DialogResult.Cancel)
{
// textBox1.Text = "";

}
frmPln.Close();


}



[解决办法]
用委托就可搞定。
[解决办法]

主窗口
public partial class FormMain : Form
{
public FormMain()
{
InitializeComponent();
}

private void label1_Click(object sender, EventArgs e)
{
FormTest frmTest = new FormTest(this.label1);
frmTest.ShowDialog();
}
}
子窗口
public partial class FormTest : Form
{
Label _lbl = null;

public FormTest(Label lbl)
{
InitializeComponent();
_lbl = lbl;
}

private void FormTest_FormClosing(object sender, FormClosingEventArgs e)
{
_lbl.Text = this.textBox1.Text;
}


}