第一种方法:

用委托,Form2和Form3是同一组

Form2

C#代码

using System;   

using System.Collections.Generic;   

using System.ComponentModel;   

using System.Data;   

using System.Drawing;   

using System.Text;   

using System.Windows.Forms;   

  

namespace TestMouseMove   

{   

    public delegate void SetVisiableHandler();   

  

    public partial class Form2 : Form   

    {   

        public Form2()   

        {   

            InitializeComponent();   

        }   

        private void button1_Click(object sender, EventArgs e)   

        {   

            Form3 frm = new Form3(new SetVisiableHandler(SetVisiable));   

            frm.Show();   

        }   

  

        private void SetVisiable()   

        {   

            SetVisiable(this.label1, !this.label1.Visible);   

        }   

  

        private void SetVisiable(Control control, bool visiable)   

        {   

            if (this.Controls.Contains(control))   

            {   

                control.Visible = visiable;   

            }   

        }   

  

    }   

}  

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

namespace TestMouseMove

{

    public delegate void SetVisiableHandler();

    public partial class Form2 : Form

    {

        public Form2()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            Form3 frm = new Form3(new SetVisiableHandler(SetVisiable));

            frm.Show();

        }

        private void SetVisiable()

        {

            SetVisiable(this.label1, !this.label1.Visible);

        }

        private void SetVisiable(Control control, bool visiable)

        {

            if (this.Controls.Contains(control))

            {

                control.Visible = visiable;

            }

        }

    }

}

Form3

C#代码

using System;   

using System.Collections.Generic;   

using System.ComponentModel;   

using System.Data;   

using System.Drawing;   

using System.Text;   

using System.Windows.Forms;   

  

namespace TestMouseMove   

{   

    public partial class Form3 : Form   

    {   

        private SetVisiableHandler m_setVisible;   

  

        public Form3(SetVisiableHandler setvisible)   

        {   

            InitializeComponent();   

            this.m_setVisible = setvisible;   

        }   

        private void btnVisible_Click(object sender, EventArgs e)   

        {   

            if (this.m_setVisible != null)   

            {   

                this.m_setVisible();   

            }   

        }   

  

    }   

}  

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

namespace TestMouseMove

{

    public partial class Form3 : Form

    {

        private SetVisiableHandler m_setVisible;

        public Form3(SetVisiableHandler setvisible)

        {

            InitializeComponent();

            this.m_setVisible = setvisible;

        }

        private void btnVisible_Click(object sender, EventArgs e)

        {

            if (this.m_setVisible != null)

            {

                this.m_setVisible();

            }

        }

    }

}

第二种方法:

用变量,Form4和Form5是同一组

Form4

C#代码

using System;   

using System.Collections.Generic;   

using System.ComponentModel;   

using System.Data;   

using System.Drawing;   

using System.Text;   

using System.Windows.Forms;   

  

namespace TestMouseMove   

{   

    public partial class Form4 : Form   

    {   

        public Form4()   

        {   

            InitializeComponent();   

        }  

 

        #region 子窗口刷新父窗口的值   

  

        private string strLabel1 = "";   

  

        public string StrLabel1   

        {   

            get  

            {   

                return strLabel1;   

            }   

            set  

            {   

                strLabel1 = value;   

                this.label1.Text = strLabel1;   

            }   

        }  

        #endregion   

  

        private void button1_Click(object sender, EventArgs e)   

        {   

            Form5 form5 = new Form5(this);//这里注意传个this   

            form5.Show();   

        }   

    }   

}  

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

namespace TestMouseMove

{

    public partial class Form4 : Form

    {

        public Form4()

        {

            InitializeComponent();

        }

        #region 子窗口刷新父窗口的值

        private string strLabel1 = "";

        public string StrLabel1

        {

            get

            {

                return strLabel1;

            }

            set

            {

                strLabel1 = value;

                this.label1.Text = strLabel1;

            }

        }

        #endregion

        private void button1_Click(object sender, EventArgs e)

        {

            Form5 form5 = new Form5(this);//这里注意传个this

            form5.Show();

        }

    }

}

Form5

C#代码

using System;   

using System.Collections.Generic;   

using System.ComponentModel;   

using System.Data;   

using System.Drawing;   

using System.Text;   

using System.Windows.Forms;   

  

namespace TestMouseMove   

{   

    public partial class Form5 : Form   

    {   

        Form4 form4 = new Form4();   

  

        public Form5(Form4 formFrm)//这个构造方法里有参数   

        {   

            form4 = formFrm; //这个必须要有   

            InitializeComponent();   

        }   

  

          

        private void button1_Click(object sender, EventArgs e)   

        {   

            form4.StrLabel1 = this.textBox1.Text;   

        }   

    }   

}