C # several methods to bind DropDownList to add new data,

C # several methods to bind DropDownList to add new data,

First: manually bind data to the foreground (applicable to fixed data items)

<Asp: DropDownList ID = "DropDownList1" runat = "server"> <asp: ListItem Value = "1"> Nanjing </asp: ListItem> <asp: listItem Value = "2"> Yangzhou </asp: ListItem> <asp: ListItem Value = "3"> Xuzhou </asp: ListItem> <asp: listItem Value = "4"> Suzhou </asp: ListItem> </asp: DropDownList>

Type 2: dynamic binding in the background

DataTable dt = new DataTable (); // The central idea is to bind the data source from the drop-down list to a table (no value is assigned to the table here) DropDownList1.DataSource = dt. defaultView; // set the field name corresponding to the DropDownList space display item. Assume that there are two columns in the table, one is bound to the Text of the drop-down list, and the other is bound to ValueDropDownList1.DataValueField = dt. columns [0]. columnName; DropDownList1.DataTextField = dt. columns [1]. columnName; DropDownList1.DataBind ();

Third: custom addition

// Method 1: Perform ListItem li = new ListItem (); li. text = "Nanjing"; li. value = "1"; DropDownList1.Items. add (li); // Method 2: ListItem () the first parameter is the Value of Text, and the second parameter is the Value of Value ListItem li = new ListItem ("Yangzhou ", "2"); DropDownList1.Items. add (li); // method 3: One-Step DropDownList1.Items. add (new ListItem ("Xuzhou", "3"); // Method 4: (cyclically Add) string [] city = {"Nanjing", "Yangzhou ", "Xuzhou", "Suzhou"}; for (int I = 0; I <city. length; I ++) {DropDownList1.Items. insert (I, city [I]); DropDownList1.Items [I]. value = I. toString ();}