DPC：Creating a DataBound List of Radio Buttons--PA
日期：2011-02-21 浏览次数：20404 次
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For More Information on ASP.NET
This article examines how to create a databound listbox using ASP.NET. For more information on ASP.NET be sure to check out the articles in the ASP.NET Article Index. The code in this article is based on the Beta 2 version of ASP.NET. To learn more about the free ASP.NET Beta 2, be sure to check out this FAQ.
Introduction
A common task Web developers face is creating a form element (such as a series of checkboxes, radio buttons, or a listbox) whose members are populated by the contents of a database table. This is quite possible (and quite easy) to accomplish with ASP.NET In fact, in a previous article (Creating Databound DropDown Lists in ASP.NET), we examined how to create a databound listbox. In this article, we'll examine how to create a series of radio buttons whose values are automagically populated from a database table! We'll also look at how to respond to the user selecting a particular option and showing more detailed information based upon the radio button selected.
The Impetus
On 4Guys there is a Sample On-Line Chapters page, which lists a number of books that have free, on-line sample chapters. All of this information is stored in a database that contains two tables: tblPublishers and tblBooks. The tblPublishers contains a row for each publisher that has a book that appears in the sample chapters listing, while the tblBooks table contains a row for each sample book. Note that the tblBooks table contains a PublisherID column which serves as a foreign key to the tblPublishers table, tying a particular publisher to a particular book.
Wouldn't it be nice to generate a list of radio buttons based upon the publishers in the tblPublishers table? From this list, the user could select a particular publisher, at which point, the user would be shown a listing of books published by that particular publisher. In creating the radio button list, we could hard code the list of publishers, but that would be subject to change any time we added or removed publishers from the tblPublishers table. Ideally, the radio button list would be dynamically generated based upon the values in the tblPublishers table.
If you'd like to see what the end result will look like, check out the CheckboxListDemo.aspx">live demo. Pretty nice looking, eh? Realize that the radio button list was created dynamically using databind (essentially three lines of code in total). And this entire page, from start to finish, took me about four minutes to write. (I type fast. :-))
Creating the Databound Radio Button List
Creating a databound series of radio buttons is painfully simply with ASP.NET. We only really need to do three things:
Create the asp:radiobuttonlist Web control, specifying the database columns we want to bind to the radio buttons' displayed text values and the hidden values that are passed along when the form is submitted.
Write the code to populate a DataReader (or DataSet) with the applicable database information.
Databind the DataReader (or DataSet) to the asp:radiobuttonlist Web control
That's it! So, let's examine each of these three steps. First, create the needed Web control in the HTML section of your ASP.NET Web page.
<html>
<body>
<form runat="server">
<b>Choose a Publisher's Books to View</b><br>
<asp:radiobuttonlist id="radlstPubs" runat="server"
DataValueField="PublisherID" DataTextField="Name" />
</form>
</body>
</html>
The two most important things to notice is that we set the asp:radiobuttonlist Web contr
For More Information on ASP.NET
This article examines how to create a databound listbox using ASP.NET. For more information on ASP.NET be sure to check out the articles in the ASP.NET Article Index. The code in this article is based on the Beta 2 version of ASP.NET. To learn more about the free ASP.NET Beta 2, be sure to check out this FAQ.
Introduction
A common task Web developers face is creating a form element (such as a series of checkboxes, radio buttons, or a listbox) whose members are populated by the contents of a database table. This is quite possible (and quite easy) to accomplish with ASP.NET In fact, in a previous article (Creating Databound DropDown Lists in ASP.NET), we examined how to create a databound listbox. In this article, we'll examine how to create a series of radio buttons whose values are automagically populated from a database table! We'll also look at how to respond to the user selecting a particular option and showing more detailed information based upon the radio button selected.
The Impetus
On 4Guys there is a Sample On-Line Chapters page, which lists a number of books that have free, on-line sample chapters. All of this information is stored in a database that contains two tables: tblPublishers and tblBooks. The tblPublishers contains a row for each publisher that has a book that appears in the sample chapters listing, while the tblBooks table contains a row for each sample book. Note that the tblBooks table contains a PublisherID column which serves as a foreign key to the tblPublishers table, tying a particular publisher to a particular book.
Wouldn't it be nice to generate a list of radio buttons based upon the publishers in the tblPublishers table? From this list, the user could select a particular publisher, at which point, the user would be shown a listing of books published by that particular publisher. In creating the radio button list, we could hard code the list of publishers, but that would be subject to change any time we added or removed publishers from the tblPublishers table. Ideally, the radio button list would be dynamically generated based upon the values in the tblPublishers table.
If you'd like to see what the end result will look like, check out the CheckboxListDemo.aspx">live demo. Pretty nice looking, eh? Realize that the radio button list was created dynamically using databind (essentially three lines of code in total). And this entire page, from start to finish, took me about four minutes to write. (I type fast. :-))
Creating the Databound Radio Button List
Creating a databound series of radio buttons is painfully simply with ASP.NET. We only really need to do three things:
Create the asp:radiobuttonlist Web control, specifying the database columns we want to bind to the radio buttons' displayed text values and the hidden values that are passed along when the form is submitted.
Write the code to populate a DataReader (or DataSet) with the applicable database information.
Databind the DataReader (or DataSet) to the asp:radiobuttonlist Web control
That's it! So, let's examine each of these three steps. First, create the needed Web control in the HTML section of your ASP.NET Web page.
<html>
<body>
<form runat="server">
<b>Choose a Publisher's Books to View</b><br>
<asp:radiobuttonlist id="radlstPubs" runat="server"
DataValueField="PublisherID" DataTextField="Name" />
</form>
</body>
</html>
The two most important things to notice is that we set the asp:radiobuttonlist Web contr
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