委托的应用（窗体间的数据传递）

  窗体间的数据传递:

下面是窗体设计还有代码，有些步骤就不用多说了，呵呵

 

 

 

在Form2窗体中右键查看代码，添加如下代码

 

 

 

 

/// <summary>

        /// 自定义事件参数类，继承自EventArgs

    /// </summary>

        public class NameInputCompleteEventArgs : EventArgs

        {

            public readonly string firstName, middleName, lastName;

            /// <summary>

            /// 构造函数并初始化变量

            /// </summary>

            /// <param name="first"></param>

            /// <param name="middle"></param>

            /// <param name="last"></param>

            public NameInputCompleteEventArgs(string first, string middle, string last)

            {

                this.firstName = first;

                this.middleName = middle;

                this.lastName = last;

            }

       

        }

        public delegate void NameInputCompleteEventHandler(object sender, NameInputCompleteEventArgs e);//声明委托

        public event NameInputCompleteEventHandler NameInputComplete;//声明事件

 

在设计窗体中双击OK键入如下代码: private void btnOk_Click(object sender, EventArgs e) // 用户点击OK时，输入完毕

        {//创建事件参数类对象

            NameInputCompleteEventArgs arg = new NameInputCompleteEventArgs(textBox1.Text, textBox2.Text, textBox3.Text);

            if (NameInputComplete != null)

        

                NameInputComplete(this, arg);

            this.Hide();

}

双击Cancel,写入this.Close();Form2操作完成

Form3中也是类似的：

在Form3窗体中右键查看代码，添加如下代码

public class NameInputCompleteEventArgs : EventArgs

        {

            public readonly string Street,City,State,ZipCode;

            public NameInputCompleteEventArgs(string street, string city, string state,string zipcode)

            {

                this.Street = street;

                this.City = city;

                this.State = state;

                this.ZipCode = zipcode;

            }

 

        }

        public delegate void NameInputCompleteEventHandler(object sender, NameInputCompleteEventArgs e);

        public event NameInputCompleteEventHandler NameInputComplete;

在设计窗体中双击OK键入如下代码

private void btnOk_Click(object sender, EventArgs e)

        {

            NameInputCompleteEventArgs arg = new NameInputCompleteEventArgs(textBox4.Text, textBox5.Text, textBox6.Text, textBox7.Text);

            if (NameInputComplete != null)

 

                NameInputComplete(this, arg);

            this.Hide();

 

        }

双击Cancel,写入this.Close();Form3操作完成

步骤五：

在Form1设计窗体中右键查看代码

        private Form2 fm2;

        private Form3 fm3;

        public Form1()

        {

            InitializeComponent();

            fm2 = new Form2();

            fm3 = new Form3();

            fm2.NameInputComplete += this.fm2_NameInputComplete;//Form2的NameInputComplete事件与响应程序进行关联

            fm3.NameInputComplete += this.fm3_NameInputComplete; //Form3的NameInputComplete事件与响应程序进行关联

 

        }

 

首先双击第一个Set按钮，显示Form2, fm2.Show();

手动输入代码Form2输入完毕的事件响应程序

private void fm2_NameInputComplete(object sender, Form2.NameInputCompleteEventArgs e)

        {

            textBox1.Text = e.firstName;

            textBox2.Text = e.middleName;

            textBox3.Text = e.lastName;

       

        }

接着在Form1代码窗口中添加

双击第二个Set按钮，显示Form3, fm3.Show();

 

private void fm3_NameInputComplete(object sender, Form3.NameInputCompleteEventArgs e)//Form3输入完毕的响应程序

        {

            textBox4.Text = e.Street;

            textBox5.Text = e.City;

            textBox6.Text = e.State;

            textBox7.Text = e.ZipCode;

       

        }

最后一个退出按钮：Application.Exit();//关闭所有应用程序窗口