In Search Of ASP. Net Controls. The Find. Control method of the System.

Web. UI. Control class appears simple enough to use. In fact, the MSDN description of the method is one simple sentence: Searches the current naming container for the specified server control. The key to using Find. Control is to invoke the method on the correct container. As a warm up, let’s say we have the following form inside of an aspx page.< form id=.

Update Label Text Outside Updatepanel Javascript

But what happens when the Text. Box is not a child of the control we query with Find. Control? Consider the following form.

Update Label Text Outside Updatepanel Onload

1. ASP.NET Panel Controls - Free ASP.NET Tutorials, Reference Manual, and Quick Guide for Beginners. Learn ASP.NET starting from Environment Setup, Basic Controls.
2. Problem : Sys.WebForms.PageRequestManagerParserErrorException will occur when redirecting ur page,lets say button click inside UpdatePanel in aspxAjax.

Let’s use the same event handler we used in the first example and see what happens. Once again we have easily located the control. For later comparison, let’s view an excerpt of the HTML source the ASP. NET form has given us.< div id=. This behavior changes when we place the textbox inside of a control implementing the INaming.

Container interface, which will change the way we use the Find. Control method. Any control implementing INaming. Container will create a new control namespace so that all child controls will have a unique ID on the page. In short, an INaming. Container control will guarantee there are no naming conflicts on a page. This behavior is best demonstrated with an example.

Find. Control in a Data. Grid. There are several ASP.

Now whenever the AJAX UpdatePanel Refreshes or does Partial PostBack I need to update the Current Time displayed in the Label. Statistical Techniques

NET controls which implement INaming. Container, including the Data.

Grid, the Repeater, and the Data. List. Let’s build a form with a Data.

Grid and view the HTML output. Using a Template.

Column, we will add a Text. Box control with the ID of Text. Box. 1 to each row of the grid. Let’s take a look at an excerpt of the HTML ASP. NET generates.< table cellspacing=. This behavior shows the INaming.

Container objects at work. The Data. Grid implements INaming. Container and will preface each child control ID with . As we will see shortly, a Data. Grid uses a collection of Data. Grid. Item controls to represent each row of data.

A Data. Grid. Item control also implements INaming. Container, and will preface the name of child controls with a it’s own generated identifier (. Besides, which control would we really expect Find. Control to return? The first Text. Box control of the page?

The last Text. Box control? Typically, when you want to find a Text. Box inside of a Data. Grid, you’ll be looking for a Text. Box on a specific row the user has chosen.

For example, we added a Select column to allow the user to click on a hyperlink to chose the selected row. Let’s try to grab the Text.

Box control in the Selected. Index. Changed event. The code above will work, as demonstrated in the following figure. We have also added some additional output to clearly see the chain of ownership leading to our Text. Box. The Text. Box.

Table. Cell object as a parent, which in turn is a child control of a Data. Grid. Item object, and so on up the line until we reach a Page control. The code to produce this dump is next.

Find. Util. . Working with the Edit. Command event handler is slightly easier, because the second parameter to the handler is of type Data. Grid. Command. Event. Args, which contains a reference to the Data. How To Install Pie Cut Corner Hinges.

Grid. Item the user has selected for interaction. Data. Grid. 1. These cases require a slightly different method of attack with Find. Control. Consider the following form< asp: Data. Grid id=Data. Grid.

We should know at this point we cannot call Find. Control on the Page, or on the Data. Grid to retrieve these controls, because they will exist inside of another INaming. Container control, specifically a Data. Grid. Item. What might be suprising however, is how we cannot use the Data.

Grid object’s Items collection as we did earlier. MSDN documentation has the following to say about the Items collection. Note: Only items bound to the data source are contained in the Items collection. The header, footer, and separator are not included in the collection.

So we will not find the header and footer Data. Grid. Item controls inside the Items collection, but all child controls must exist inside the Controls collection. In this case, our earlier dump of the Data.

Grid control hierarchy will prove useful. We know the parent of each Data. Grid. Item is a Data.

Grid. Table, and the parent of the Data. Grid. Table is the Data.

Grid control itself. We will have to assume the Data. Grid. Table is the first control in the Data.

Grid, and the header row will be the first control of the Data. Grid. Table (consequently the footer is the last control of the Data.

Grid. Table). Thus the following code: private void Data. Grid. 1. Seeing hard coded index values into the Controls collection is a bit worrisome.

If your control changes, or the Data. Grid control changes in a newer version of the framework, this code could break. An alternate solution could involve looping through the Data. Grid. Table controls looking for Data. Grid. Item objects with a Item. Type property equal to List. Item. Header or List.

Item. Footer. Whichever you decide, neither feels extremely robust in the face of future changes. Find. Control in Repeater controls. Like the Data. Grid, the Repeater is an INaming. Container. Let’s take a look at the following form which displays authors from SQL Server.< asp: Repeater id=. Every Button control will use the same event handler where we can grab the corresponding Text. Box control in the row with the following code.

Button. 1. In the following screen shot, you can see the parent of the Text. Box (and the Button) is a Repeater. Item control (which also implements INaming. Container). Thus the first Text.

Box appearing on the screen will have an unique ID of Repeater. Suppose we added a second button at the bottom of the form with the repeater. When the user clicks this button we want to loop the repeater collecting the contents of each Text. Box control from every row.

You can accomplish this task with the following code. Button. 2. Let’s through the following user control into a form.< %@ Control Language=. For instance, if we placed two of these user controls on the same form, without munging the names we would have two Text. Box. 1 controls on the same form. Although you generally will not need to do this, you can find a control from the code behind of a user control as easily as the first example in this articleprivate void Button. In the following example, we will also use Find. Control to find our user control.

Page. The behavior of Find. Control makes perfect sense once you understand the purpose of INaming. Container and begin using Find. Control on the correct objects.

ASP. NET - Panel Controls. The Panel control works as a container for other controls on the page. It controls the appearance and visibility of the controls it contains. It also allows generating controls programmatically. The basic syntax of panel control is as follows. Panel ID= . Hence it inherits all the properties, methods and events of the same. It does not have any method or event of its own.

However it has the following properties of its own: Properties. Description. Back. Image. Url. URL of the background image of the panel. Default. Button. Gets or sets the identifier for the default button that is contained in the Panel control. Direction. Text direction in the panel. Grouping. Text. Allows grouping of text as a field.

Horizontal. Align. Horizontal alignment of the content in the panel. Scroll. Bars. Specifies visibility and location of scrollbars within the panel. Wrap. Allows text wrapping. Let us start with a simple scrollable panel of specific height and width and a border style.

The Scroll. Bars property is set to both the scrollbars, hence both the scrollbars are rendered. The source file has the following code for the panel tag. Panel ID=. The user provides the number of label controls and textboxes to be generated on the panel. The controls are generated programmatically. Change the properties of the panel using the properties window. When you select a control on the design view, the properties window displays the properties of that particular control and allows you to make changes without typing. The source file for the example is as follows.