在winForm 中实现两个窗体间的数据传递

一共有4种实现方法

Using constructor
Using objects
Using properties
Using delegates

这里主要介绍方法3、4
方法3：

Step 1: Add a property in form1 to retrieve value from textbox.

public string _sendtxt
        {
            get{return this.txtBox1.Text.ToString().Trim();}
        }

Step 2: Add a property in form2 to set the labels’ text

public string _recevicetxt
        {
            set { this.label1.Text=value; }
        }

Step 3: In form1’s button click event handler add the following code.

private void btnsend_Click(object sender, EventArgs e)
        {
            Form2 frm2 = new Form2();
            frm2.Show();
            frm2._recevicetxt = _sendtxt;
        }

方法4：

Step 1: Add a delegate signature to form1 as below

public delegate void delPassData(TextBox text);

Step 2: In form1’s button click event handler instantiate form2 class and delegate. Assign a function in form2 to the delegate and call the delegate as below

private void btnsend_Click(object sender, System.EventArgs e)
        {
            Form2 frm = new Form2();
            delPassData del = new delPassData(frm.funData);
            del(this.textBox1);
            frm.Show();
        }

Step 3: In form2, add a function to which the delegate should point to. This function will assign textbox’s text to the label.

public void funData(TextBox txtForm1)
        {
            label1.Text = txtForm1.Text;
        }

详细介绍请参考：http://www.codeproject.com/useritems/pass_data_between_forms.asp

FrmM:   txt1、txt2、txt3的Modify设为:Public
private void btn1_Click(object sender, EventArgs e)
        {
            FrmS fs = new FrmS();
            fs.Owner = this;//Owner:拥有当前窗体的窗体
            fs.ShowDialog();
        }

FrmS:
private void dataGridView1_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
        {
            FrmM fm = (FrmM)this.Owner;
            fm.txt1.Text = dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString();
            fm.txt2.Text = dataGridView1.Rows[e.RowIndex].Cells[1].Value.ToString();
            fm.txt3.Text = dataGridView1.Rows[e.RowIndex].Cells[2].Value.ToString();
            this.Close();
        }