C#如何实现两个WINFORM之间的访问

namespace WA_Test1
{
/// <summary>
/// 作者：Davi
/// </summary>
//委托
public delegate string chktext(int myInt);

public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.Button button1;
public System.Windows.Forms.TextBox textBox1;
//public Form1 frm1=new Form1();
/// <summary>
/// 必需的设计器变量。
/// </summary>
private System.ComponentModel.Container components = null;

public Form1()
{
//
// Windows 窗体设计器支持所必需的
//
InitializeComponent();

//
// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
//
}

/// <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 Form Designer generated code
/// <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.button1 = new System.Windows.Forms.Button();
this.textBox1 = new System.Windows.Forms.TextBox();
this.SuspendLayout();
//
// button1
//
this.button1.Location = new System.Drawing.Point(128, 56);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(56, 24);
this.button1.TabIndex = 0;
this.button1.Text = "button1";
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// textBox1
//
this.textBox1.Location = new System.Drawing.Point(16, 56);
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(88, 21);
this.textBox1.TabIndex = 1;
this.textBox1.Text = "textBox1";
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
this.ClientSize = new System.Drawing.Size(304, 117);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.textBox1,
this.button1});
this.MaximizeBox = false;
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);

}
#endregion

/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main()
{
Form3 frm3=new Form3();
Application.Run(frm3.GetForm1());
}

private void button1_Click(object sender, System.EventArgs e)
{
Form3 frm3=new Form3();
(frm3.GetForm2()).Show();
//frm3.InputBox("Title","please enter some value","20");
//MessageBox.Show(frm3.InputBox().ToString());
}

private void button2_Click(object sender, System.EventArgs e)
{
//
}

namespace WA_Test1
{
/// <summary>
/// 作者：Davi
/// </summary>
public class Form2 : System.Windows.Forms.Form
{
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.Button button1;
/// <summary>
/// 必需的设计器变量。
/// </summary>
private System.ComponentModel.Container components = null;

public Form2()
{
//
// Windows 窗体设计器支持所必需的
//
InitializeComponent();

//
// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
//
}

/// <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 Form Designer generated code
/// <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.button1 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// textBox1
//
this.textBox1.Location = new System.Drawing.Point(16, 40);
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(152, 21);
this.textBox1.TabIndex = 0;
this.textBox1.Text = "textBox1";
//
// button1
//
this.button1.Location = new System.Drawing.Point(56, 72);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(168, 24);
this.button1.TabIndex = 1;
this.button1.Text = "更改Form1的TextBox1";
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// Form2
//
this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
this.ClientSize = new System.Drawing.Size(272, 117);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.button1,
this.textBox1});
this.Name = "Form2";
this.Text = "Form2";
this.ResumeLayout(false);

}
#endregion