The comment is now awaiting moderation. You will be notified via email when the author replies to your comment. Please select a comment to reply. You can add your comment about this article using the form below. Make sure you provide a valid email address else you won't be notified when the author replies to your comment Please note that all comments are moderated and will be deleted if they are Not relavant to the article Spam Advertising campaigns or links to other sites Abusive content.
Please do not post code, scripts or snippets. Required Invalid Email Address. Security code:. Required Invalid security code. I declare, I accept the site's Privacy Policy. Add Comment. Disclaimer : The code samples and API available at www. You are free to use it for commercial as well as non-commercial use at your own risk, but you cannot use it for posting on blogs or other tutorial websites similar to www.
All the code samples and API provided by the authors are solely their creation and neither the author nor the site are responsible if it does not work as intended. I agree to the above terms. To watch these events in action, we can create a simple event tracker application. All this application does is write a new entry to a list control every time one of the events it's monitoring occurs. This allows you to see the order in which events are triggered.
Collections; using System. Configuration; using System. Data; using System. Web; using System. Security; using System. UI; using System. HtmlControls; using System. WebControls; using System. WebParts; public partial class EventTracker : System.
The Log method adds the text and automatically scrolls to the bottom of the list each time a new entry is added, thereby ensuring that the most recent entries remain visible. All the change events are handled by the same method, CtrlChanged. Like Liked by 1 person. You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email. Notify me of new posts via email.
You will see that after each click, the items in the dropdownlist will be duplicated: First, when you clicked the button, the page will be submitted to ASP. The first option is using IsPostBack property of Page class: IsPostBack is a Boolean-type property of the Page class and its value is true if the server receives a request as a result of a postback event such as button click.
For this, we need to set EnableViewState to false for the dropdownlist: Similarly, when you click the button, your selection will be lost, although you will see the correct list of countries. IsPostBack condition in CodeBehind while still keeping the ViewState disabled for the dropdownlist: When you click the button, the dropdownlist will be cleared see the following image.
You will get the following error: This is because you are trying to access a list item that does not exist NULL. How about if we remove the Page. Share this: Twitter Facebook. Like this: Like Loading Basic ASP. Net Entity Framework To answer your question, I know why: there is no indexing. We need an array.
Leave a Reply Cancel reply Enter your comment here Fill in your details below or click an icon to log in:. Email required Address never made public. Name required. Loading Comments But when you add ASP. Depending on the item selected in the DropDownList you need to fetch data from SQL server and display it in the table.
One way to do this is to select an item from the DropDownList and click on a 'Submit' button so as to send the selection made to the server. A more logical arrangement would be to submit the form as soon as the selection in the DropDownList changes. This later mechanism is called 'AutoPostBack'. An AutoPostBack can be of two types:. This arrangement is suitable in cases where a large part of the page will be affected due to the change in the selection. The advantage of this approach is that it requires little client side JavaScript code.
However, the downside is that the entire page will be refreshed thus requiring more time and bandwidth to re-display the page.
0コメント