C#窗体间通讯的几种处理方法

应用程序开发中，经常需要多窗体之间进行数据通信，写几个例子，把几种常用的通信方式总结一下：

主窗体Form1是一个ListBox，单击选中某列时，弹出窗体Form2，Form2中两个控件，一个是TextBox，显示选中的该列的文本，另一个是按钮，点击时将修改后的值回传，且在Form1中修改相应的列的文本，同时Form2关闭。

方法一：传值

publicpartial class Form2 : Form
    {
        private string text;
        private ListBox lb;
        private int index;

       //构造函数接收三个参数：选中行文本，ListBox控件，选中行索引
        public Form2(string text,ListBox lb,int index)
        {
            this.text = text;
            this.lb = lb;
            this.index = index;
            InitializeComponent();
            this.textBox1.Text = text;
        }

        private void btnChange_Click(object sender, EventArgs e)
        {           

            string text = this.textBox1.Text;
            this.lb.Items.RemoveAt(index);
            this.lb.Items.Insert(index, text);
            this.Close();
        }
    }

 Form1中new窗体2时这么写：

public partial class Form1 :Form
    {
        int index = 0;
        string text = null;
        public Form1()
        {
            InitializeComponent();
        }

        private void listBox1_SelectedIndexChanged(object sender, EventArgse)
        {
            if (this.listBox1.SelectedItem != null)
            {
                text = this.listBox1.SelectedItem.ToString();
                index = this.listBox1.SelectedIndex;

               //构造Form2同时传递参数
                Form2 form2 = new Form2(text, listBox1, index);
                form2.ShowDialog();
            }
        }

OK，方法一的解决方法就是这样，好处是直观，需要什么就传什么，缺点也是显而易见的，如果窗体1中需要修改的是一百个控件，难道构造的时候还传100个参数进去？况且如果其他窗体仍然需要弹Form2，那Form2就废了，只能供窗体1使用，除非写重载的构造函数，不利于代码的复用，继续看下一个方法。

//声明Form2继承于Form1

public partial classForm2 : Form1
    {
         publicint index;

        public ListBox lb;
        public Form2(string text)
        {  

           //将继承过来的listBox设置为不可见

            this.listBox1.Visible=false;
            InitializeComponent();
            this.textBox1.Text = text;
        }
        private void btnChange_Click(object sender, EventArgs e)
        {
            string text = this.textBox1.Text;
            this.lb.Items.RemoveAt(index);
            this.lb.Items.Insert(index,text);         
            this.Close();

        }
    }

public partial class Form1 :Form
    {
        public int index = 0;
        public string text = null;
        public Form1()
        {
            InitializeComponent();
        }

        private void listBox1_SelectedIndexChanged(object sender, EventArgse)
        {
            if (this.listBox1.SelectedItem != null)
            {
                text = this.listBox1.SelectedItem.ToString();
                index = this.listBox1.SelectedIndex;
                Form2 form2 = new Form2(text);

               //构造完Form2后，为Form2中各参数赋值
                form2.lb =this.listBox1;               
                form2.index = index;
                form2.Show();
            }
        }
    }

this.lb=base.listBox1;

this.index=base.index;
 

//定义一个需要string类型参数的委托

publicdelegate void MyDelegate(string text);

public partial class Form2 :Form1
    {

       //定义该委托的事件
        public event MyDelegate MyEvent;
        public Form2(string text)
        { 
            InitializeComponent();
            this.textBox1.Text = text;
        }
        private void btnChange_Click(object sender, EventArgs e)
        {

           //触发事件，并将修改后的文本回传
            MyEvent(this.textBox1.Text);
            this.Close();
        }
    }

public partial class Form1 :Form
    {
        public int index = 0;
        public string text = null;
        public Form1()
        {
            InitializeComponent();
        }

        private void listBox1_SelectedIndexChanged(object sender, EventArgse)
        {
            if (this.listBox1.SelectedItem != null)
            {
                text = this.listBox1.SelectedItem.ToString();
                index = this.listBox1.SelectedIndex;
                Form2 form2 = new Form2(text);

               //注册form2_MyEvent方法的MyEvent事件
                form2.MyEvent += new MyDelegate(form2_MyEvent);
                form2.Show();
            }
        }

       //处理

        void form2_MyEvent(string text)
        {
            this.listBox1.Items.RemoveAt(index);
            this.listBox1.Items.Insert(index, text);
        }
    }