Pick Asp. NET standard control (TextBox control)

TextBox control

A TextBox control, also known as a TextBox control, provides the user with the ability to enter text.

1. Property

The common properties and descriptions of the TextBox control are shown in table 1.

Table 1 Common Properties and descriptions of TextBox controls

Properties	Description
AutoPostBack	Gets or sets a value that indicates whether automatic postback to the server occurs whenever the user presses the 〈enter〉 key or the 〈tab〉 key in a TextBox control
CausesValidation	Gets or sets a value that indicates whether validation is performed when the TextBox control is set to validate when a postback occurs
Id	Control ID
Text	The text to display for the control
TextMode	Gets or sets the behavior mode (single row, multiline, or password) of the TextBox control
Width	Width of the control
Visible	Whether the control is visible
ReadOnly	Gets or sets a value that indicates whether the contents of a TextBox control can be read-only
CssClass	Control-Rendered style
BackColor	The background color of the control
Enabled	Whether the control is available

Most of the property settings of a TextBox control are similar to a label control, see the Label control property settings below, which mainly describes the TextMode property.

The TextMode property is primarily used to control the way text is displayed for a TextBox control, with the following 3 options for setting the property.

L single Row (Singleline): The user can enter information only on one line, and optionally limit the number of characters the control receives.

L Multi-line (MultiLine): Allows the user to enter multiple lines of text and perform line breaks when the text is very long.

L Password (Password): Masks the characters entered by the user with a black point () to hide the information.

For example, when verifying a user's login password, you can set the TextMode property of the TextBox control to password, which runs as shown in effect 1.

When you fill out a memo, the text can be a lot, and you can set the TextBox control's TextMode property to Multiline, which runs as shown in result 2.

Figure 1 Hide Login Password

Figure 2 Fill in the Notes information

2. Method

The common method of a TextBox control is similar to a Label control, and table 2 lists some of its common methods.

Table 2 Common methods and descriptions of TextBox controls

Method	Description
DataBind	Binds a data source to the invoked server control and all its child controls
Focus	Set input focus for a control
Dispose	Enables the server control to perform the final cleanup operation before it is freed from memory
Equals	Determine if two object instances are equal

The focus method of the Extbox control is primarily used to obtain its focus, for example, when a user writes the following code in a Page_Load event that contains a TextBox control page:

protected void Page_Load (object sender, EventArgs e)

{

Textbox1.focus ();

}

Run result 3 as shown.

Figure 3 Getting the TextBox control focus

3. Event

TextBox control common events are similar to label controls, see the Label control common events.

4. Example

Example:

TextBox Control Example

The following example compares the effect of a 3 TextBox control by setting a different TextMode property value. Create a new Web site, the default home page is default.aspx, add 3 TextBox controls on the Default.aspx page, and their properties are set as follows.

L Enter a TextBox control for the user name: The TextMode property is set to the Singleline,backcolor property of #ffe0c0 (light yellow), and the BorderColor property is Blue (blue).

L Enter the password for the TextBox control: TextMode property is set to password.

• TextBox control for entering memo information: The TextMode property is set to Multiline.

Execute the program and enter the text in 3 text boxes, as shown in the example run result 4.

Figure 4 TextBox Control Example

The complete code of the program is as follows:

★★★★★default.aspx.cs code file ★★★★★

1 using System;
2 using System.Data;
3 using System.Configuration;
4 using System.Web;
5 using System.Web.Security;
6 using System.Web.UI;
7 using System.Web.UI.WebControls;
8 using System.Web.UI.WebControls.WebParts;
9 using System.Web.UI.HtmlControls;
10
public partial class _default:system.web.ui.page
12 {
protected void Page_Load (object sender, EventArgs e)
14 {
15}
16
protected void textBox1_TextChanged (object sender, EventArgs e)
18 {
19}
20}

★★★★★default.aspx Design File ★★★★★

<%@ page language= "C #" autoeventwireup= "true" codefile= "Default.aspx.cs" inherits= "_default"%>

<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">


<title>textbox Control Example </title>
<body>

<form id= "Form1" runat= "Server" >
<div>
User name: <asp:textbox id= "TextBox1" runat= "Server" backcolor= "#FFE0C0" bordercolor= "Blue"
Ontextchanged= "textBox1_TextChanged" ></asp:TextBox>
<br/>
Secret &nbsp; Code: <asp:textbox id= "TextBox2" runat= "Server" textmode= "Password" width= "149px" ></asp:TextBox>
<br/>
Preparation &nbsp; Note: <asp:textbox id= "TextBox3" runat= "Server" textmode= "MultiLine" ></asp:TextBox></div>
</form>
</body>

Pick Asp. NET standard control (TextBox control)