binding的例子

http://msdn.microsoft.com/zh-cn/library/system.windows.forms.binding%28v=vs.110%29.aspxusing System;using System.Data;using System.Drawing;using System.Globalization;using System.Windows.Forms;public class Form1 : System.Windows.Forms.Form{   private System.ComponentModel.Container components;   private Button button1;   private Button button2;   private Button button3;   private Button button4;   private TextBox text1;   private TextBox text2;   private TextBox text3;   private BindingManagerBase bmCustomers;   private BindingManagerBase bmOrders;   private DataSet ds;   private DateTimePicker DateTimePicker1;   public Form1()   {      // Required for Windows Form Designer support.      InitializeComponent();      // Call SetUp to bind the controls.      SetUp();   }   private void InitializeComponent()   {      // Create the form and its controls.      this.components = new System.ComponentModel.Container();      this.button1 = new System.Windows.Forms.Button();      this.button2 = new System.Windows.Forms.Button();      this.button3 = new System.Windows.Forms.Button();      this.button4 = new System.Windows.Forms.Button();      this.text1= new System.Windows.Forms.TextBox();      this.text2= new System.Windows.Forms.TextBox();      this.text3= new System.Windows.Forms.TextBox();      this.DateTimePicker1 = new DateTimePicker();      this.Text = "Binding Sample";      this.ClientSize = new System.Drawing.Size(450, 200);      button1.Location = new System.Drawing.Point(24, 16);      button1.Size = new System.Drawing.Size(64, 24);      button1.Text = "<";      button1.Click+=new System.EventHandler(button1_Click);      button2.Location = new System.Drawing.Point(90, 16);      button2.Size = new System.Drawing.Size(64, 24);      button2.Text = ">";      button2.Click+=new System.EventHandler(button2_Click);      button3.Location = new System.Drawing.Point(90, 100);      button3.Size = new System.Drawing.Size(64, 24);      button3.Text = "<";      button3.Click+=new System.EventHandler(button3_Click);      button4.Location = new System.Drawing.Point(150, 100);      button4.Size = new System.Drawing.Size(64, 24);      button4.Text = ">";      button4.Click+=new System.EventHandler(button4_Click);      text1.Location = new System.Drawing.Point(24, 50);      text1.Size = new System.Drawing.Size(150, 24);      text2.Location = new System.Drawing.Point(190, 50);      text2.Size = new System.Drawing.Size(150, 24);      text3.Location = new System.Drawing.Point(290, 150);      text3.Size = new System.Drawing.Size(150, 24);      DateTimePicker1.Location = new System.Drawing.Point(90, 150);      DateTimePicker1.Size = new System.Drawing.Size(200, 800);      this.Controls.Add(button1);      this.Controls.Add(button2);      this.Controls.Add(button3);      this.Controls.Add(button4);      this.Controls.Add(text1);      this.Controls.Add(text2);      this.Controls.Add(text3);      this.Controls.Add(DateTimePicker1);   }   protected override void Dispose( bool disposing ){      if( disposing ){         if (components != null){            components.Dispose();}      }      base.Dispose( disposing );   }   public static void Main()   {      Application.Run(new Form1());   }   private void SetUp()   {      // Create a DataSet with two tables and one relation.      MakeDataSet();      BindControls();   }   protected void BindControls()   {      /* Create two Binding objects for the first two TextBox          controls. The data-bound property for both controls          is the Text property. The data source is a DataSet          (ds). The data member is the           "TableName.ColumnName" string. */      text1.DataBindings.Add(new Binding      ("Text", ds, "customers.custName"));      text2.DataBindings.Add(new Binding      ("Text", ds, "customers.custID"));      /* Bind the DateTimePicker control by adding a new Binding.          The data member of the DateTimePicker is a          TableName.RelationName.ColumnName string. */      DateTimePicker1.DataBindings.Add(new       Binding("Value", ds, "customers.CustToOrders.OrderDate"));      /* Add event delegates for the Parse and Format events to a          new Binding object, and add the object to the third          TextBox control's BindingsCollection. The delegates          must be added before adding the Binding to the          collection; otherwise, no formatting occurs until          the Current object of the BindingManagerBase for          the data source changes. */         Binding b = new Binding         ("Text", ds, "customers.custToOrders.OrderAmount");      b.Parse+=new ConvertEventHandler(CurrencyStringToDecimal);      b.Format+=new ConvertEventHandler(DecimalToCurrencyString);      text3.DataBindings.Add(b);      // Get the BindingManagerBase for the Customers table.       bmCustomers = this.BindingContext [ds, "Customers"];      /* Get the BindingManagerBase for the Orders table using the          RelationName. */       bmOrders = this.BindingContext[ds, "customers.CustToOrders"];   }   private void DecimalToCurrencyString(object sender, ConvertEventArgs cevent)   {      /* This method is the Format event handler. Whenever the          control displays a new value, the value is converted from          its native Decimal type to a string. The ToString method          then formats the value as a Currency, by using the          formatting character "c". */      // The application can only convert to string type.       if(cevent.DesiredType != typeof(string)) return;      cevent.Value = ((decimal) cevent.Value).ToString("c");   }   private void CurrencyStringToDecimal(object sender, ConvertEventArgs cevent)   {         /* This method is the Parse event handler. The Parse event          occurs whenever the displayed value changes. The static          ToDecimal method of the Convert class converts the          value back to its native Decimal type. */      // Can only convert to decimal type.      if(cevent.DesiredType != typeof(decimal)) return;      cevent.Value = Decimal.Parse(cevent.Value.ToString(),      NumberStyles.Currency, null);      /* To see that no precision is lost, print the unformatted          value. For example, changing a value to "10.0001"          causes the control to display "10.00", but the          unformatted value remains "10.0001". */      Console.WriteLine(cevent.Value);   }   private void button1_Click(object sender, System.EventArgs e)   {      // Go to the previous item in the Customer list.      bmCustomers.Position -= 1;   }   private void button2_Click(object sender, System.EventArgs e)   {      // Go to the next item in the Customer list.      bmCustomers.Position += 1;   }   private void button3_Click(object sender, System.EventArgs e)   {      // Go to the previous item in the Orders list.      bmOrders.Position-=1;   }   private void button4_Click(object sender, System.EventArgs e)   {      // Go to the next item in the Orders list.      bmOrders.Position+=1;   }   // Create a DataSet with two tables and populate it.   private void MakeDataSet()   {      // Create a DataSet.      ds = new DataSet("myDataSet");      // Create two DataTables.      DataTable tCust = new DataTable("Customers");      DataTable tOrders = new DataTable("Orders");      // Create two columns, and add them to the first table.      DataColumn cCustID = new DataColumn("CustID", typeof(int));      DataColumn cCustName = new DataColumn("CustName");      tCust.Columns.Add(cCustID);      tCust.Columns.Add(cCustName);      // Create three columns, and add them to the second table.      DataColumn cID =          new DataColumn("CustID", typeof(int));      DataColumn cOrderDate =          new DataColumn("orderDate",typeof(DateTime));      DataColumn cOrderAmount =          new DataColumn("OrderAmount", typeof(decimal));      tOrders.Columns.Add(cOrderAmount);      tOrders.Columns.Add(cID);      tOrders.Columns.Add(cOrderDate);      // Add the tables to the DataSet.      ds.Tables.Add(tCust);      ds.Tables.Add(tOrders);      // Create a DataRelation, and add it to the DataSet.      DataRelation dr = new DataRelation      ("custToOrders", cCustID , cID);      ds.Relations.Add(dr);      /* Populate the tables. For each customer and order,          create two DataRow variables. */      DataRow newRow1;      DataRow newRow2;      // Create three customers in the Customers Table.      for(int i = 1; i < 4; i++)      {         newRow1 = tCust.NewRow();         newRow1["custID"] = i;         // Add the row to the Customers table.         tCust.Rows.Add(newRow1);      }      // Give each customer a distinct name.      tCust.Rows[0]["custName"] = "Alpha";      tCust.Rows[1]["custName"] = "Beta";      tCust.Rows[2]["custName"] = "Omega";      // For each customer, create five rows in the Orders table.      for(int i = 1; i < 4; i++)      {         for(int j = 1; j < 6; j++)         {            newRow2 = tOrders.NewRow();            newRow2["CustID"]= i;            newRow2["orderDate"]= new DateTime(2001, i, j * 2);            newRow2["OrderAmount"] = i * 10 + j  * .1;            // Add the row to the Orders table.            tOrders.Rows.Add(newRow2);         }      }   } }