NET to persist page-level changes to non-postback properties on controls as pages post back to the server. ViewState can also wreak havoc with client-side scripting applications that modify control properties that are tracked by ViewState, which can produce very unpredictable results on a Postback after client-side updates.
Yes, you lose some functionality, but you can easily implement most of the common functionality in non-ViewState workarounds. NET 3. In short, it was an all or nothing approach. With ASP. It allows you to disable ViewState globally either on the page or web. The main benefit of ViewStateMode is that it allows you to more easily turn off ViewState for most of the page and enable only a few key controls that might need it.
For me personally, this is a perfect combination as most of my WebForm apps can get away without any ViewState at all. HTML encoding is an important feature to prevent cross-site scripting attacks in data entered by users on your site.
The encoding expression syntax looks like this:. Effectively this is a shortcut to:. Anything that makes it easier and less verbose to HtmlEncode text is a welcome addition to avoid potential cross-site scripting attacks.
ScriptManager Enhancements. The ASP. NET ScriptManager control in the past has introduced some nice ways to take programmatic and markup control over script loading, but there were a number of shortcomings in this control. Assembly names for loading scripts from resources can now be simple names rather than fully qualified assembly names, which make it less verbose to reference scripts from assemblies loaded from your bin folder or the assembly reference area in web.
The ScriptManager in 4. Even nicer: You can specify the URL that the combined script is served with. Check out the following script manager markup that combines several static file scripts and a script resource into a single ASP. All you need to do to make this work is ensure that allscripts.
This is pretty cool, but you want to be real careful that you use unique URLs for each combination of scripts you combine or else browser and server caching will easily screw you up royally. The script manager also allows you to override native ASP. So if you want custom behavior or you want to fix a possible bug in the core libraries that normally are loaded from resources, you can now do this simply by referencing the script resource name in the Name property and pointing at System.
Web for the assembly. Not a common scenario, but when you need it, it can come in real handy. Still, there are a number of shortcomings in this control.
The CdnUrl is static and compiled in, which is very restrictive. This, in turn, means there is little control over script loading order, which can be problematic for control developers. Another minor but useful feature is that you can now directly access the MetaDescription and MetaKeywords properties on the Page object to set the corresponding meta tags programmatically.
You can now just set these properties programmatically on the Page object in any Control derived class on the page or the Page itself:. Nothing earth shattering but quite convenient. Visual Studio Enhancements for Web Development. For Web development there are also a host of editor enhancements in Visual Studio Some of these are not Web specific but they are useful for Web developers in general.
Text Editors. Throughout Visual Studio , the text editors have all been updated to a new core engine based on WPF which provides some interesting new features for various code editors including the nice ability to zoom in and out with Ctrl-MouseWheel to quickly change the size of text.
This issue seems to be well documented so I suspect this will be addressed soon with a hotfix or within the first service pack. Overall though, the code editors work very well, especially given that they were re-written completely using WPF, which was one of my big worries when I first heard about the complete redesign of the editors.
Visual Studio now targets all versions of the. NET framework from 2. NET 2, 3. This is the most frequently asked question for beginners, even for intermediate developers, while displaying data on the web forms when there are no records present in the Database.
But there are sometimes a requirement to display a table on the web page if there is no records found in the database so that the user can add a new record by filling in the fields on the table and by clicking the button. In such cases we mostly make use of a table control along with the GridView control whereby setting its the table's visibility to true or false depending on whether there are records in the DB or not.
The alternative is to use an EmptyDataTemplate of the GridView control or the data control, whichever you are using. Whereby the user must input the data in the respective fields and on the click of the button, all the data entered by the user is stored in the DB and finally the stored Data is displayed in the GridView control.
Something about the EmptyDataTemplate is that it's a template that can display any piece of information in a specified format when no records are present in the Database.
It's simple to define the only thing that you need to do, which is to create a class that will implement the ITemplate interface and define your layout of your EmptyDataTemplate. And then finally you need to set the GridView. EmptyDataTemplate to your Template that you created. Ok now let's move on towards our example, as you all know. Now let's try to implement our goal. Starting with our That Queries.
Over here we'll be making use of an Employees table stored in an Oracle Database. The following is the script for that:. Until now we have created a table and a procedure that will allow us to read the Employees table information or insert data into the Employees table.
Now let's use a webform in Visual Studio named test. Now when I try to run the file all I get is a blank page like the following. For creating a table we need the cell, in other words the Column and the Row.
The following are the two classes that we can call; they have helper classes that will allow us to create a column and a row for our GridView's EmptyDataTemplate. Since all the helper classes are done, the following is the source code for it. For now, just keep this in mind because it will be used at the end of the article where we will try to insert records into the Employee table using an xmlHttpRequest object.
If you observe the source code you will find the following things Our EmptyGridTemplate inherits from the ITemplate class that has one function named InstantiateIn Control container that is called automatically when you bind this class to your data control; in our case the GridView control's EmptyDataTemplate.
In the InstantiateIn function we are using an UpdatePanel, in other words all of our table's data will be placed inside an updatepanel. After adding all the table data to the updatePanel control, we are adding the update panel to the container control inside the InstantiateIn function. Ask Question.
Net GridView. You might also like to read:. HTML Markup. You will need to import the following namespaces. Imports System. Binding the GridView. I am populating the GridView with some dummy records using DataTable. Add 1, "John Hammond" , "United States" ;.
Add 2, "Mudassar Khan" , "India" ;. Add 3, "Suzanne Mathews" , "France" ;. Add 4, "Robert Schidner" , "Russia" ;. DataBind ;. If Not Me. IsPostBack Then. Dim dt As New DataTable. Add 1, "John Hammond" , "United States".
Add 2, "Mudassar Khan" , "India". Add 3, "Suzanne Mathews" , "France". Add 4, "Robert Schidner" , "Russia". End If.
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