TextChanged event of TextBox control may not fire if AutoComplete is enabled in Internet Explorer

Article
01/25/2022

Warning

The retired, out-of-support Internet Explorer 11 desktop application has been permanently disabled through a Microsoft Edge update on certain versions of Windows 10. For more information, see Internet Explorer 11 desktop app retirement FAQ.

This article provides the workaround to solve the issue that the TextChanged event of a TextBox control does not fire if the AutoComplete feature is enabled in Internet Explorer.

Original product version: Internet Explorer
Original KB number: 873198

Symptoms

When you enable the AutoComplete feature of forms in Microsoft Internet Explorer and then you select any text from the AutoComplete drop-down list of a TextBox control in a Web application, the TextChanged event of the TextBox control does not fire even though the text in the TextBox control changes.

Cause

This behavior occurs because Internet Explorer cannot fire the TextChanged event of a TextBox control when you select text from the drop-down list by using the AutoComplete feature.

Workaround

To work around this behavior, disable the AutoComplete feature of the Web form. To disable the feature, follow these steps:

In Solution Explorer, right-click WebForm1.aspx, and then click View Designer.
Switch to the HTML view of WebForm1.aspx.

Locate the following code:

<form id="Form1" method="post" runat="server">

Replace the code that you located in step 3 with the following code:
```
<form id="Form1" method="post" runat="server" autocomplete="off">
```

Steps to reproduce the behavior

Step 1: Enable the AutoComplete feature for forms

Start Internet Explorer.
On the Tools menu, click Internet Options. The Internet Options dialog box appears.
On the Content tab, click AutoComplete under Personal information. The AutoComplete Settings dialog box appears.
Under Use AutoComplete for, click to select the Forms check box, and then click OK.
In the Internet Options dialog box, click OK.

Step 2: Create a Web application that contains a TextBox control

Start Microsoft Visual Studio .NET.
On the File menu, point to New, and then click Project. The New Project dialog box appears.
Click Visual C# Projects under Project Types, click ASP.NET Web Application under Templates, type http://localhost/MyTestAppin the Location box, and then click OK.
In Solution Explorer, right-click WebForm1.aspx, and then click View Designer.
On the View menu, click Toolbox.
Add a TextBox control to the Web form. By default, a TextBox control that is named TextBox1 is created.
In the Properties window of the TextBox1 TextBox control, set the AutoPostBack property to True.
In the Properties window of the TextBox1 TextBox control, click Events, and then double-click TextChanged. The TextBox1_TextChanged procedure is added in the Code view of the WebForm1.aspx file.
Insert a breakpoint at the TextBox1_TextChanged procedure.
On the File menu, click Save All to save all the files.

Step 3: Build and then debug the Web application

On the Build menu, click Build Solution.
On the Debug menu, click Start. The WebForm1 - Microsoft Internet Explorer Web page appears.
In the text box, type text1, and then press ENTER. You notice that the debugger stops at the TextBox1_TextChanged procedure in the Code view of the WebForm1.aspx file.
On the Debug menu, click Continue.
In the text box on the WebForm1 - Microsoft Internet Explorer Web page, type text2, and then press ENTER. You notice that the debugger stops again at the TextBox1_TextChanged procedure in the code view of the WebForm1.aspx file.
On the Debug menu, click Continue.
In the text box on the WebForm1 - Microsoft Internet Explorer Web page, type t. You notice a drop-down list of words that you typed earlier.
Use the DOWN ARROW key to select text1, and then press ENTER.

You see that the TextChanged event of the TextBox1 TextBox control does not fire.

References

For more information, see TextBox.AutoPostBack Property.