Eval vs Bind
Eval and Bind functions generally find applications in databinding in ASP.NET. ASP.NET was developed by Microsoft for the benefit of web programmers and website designers. ASP.NET helps in making dynamic content for web pages and websites, and for web related software and applications. As a matter fact, ASP.NET web pages are considered to be the basic building blocks for different advanced web applications. Web pages with the extension of .aspx have either static or dynamic content stored on them – the usage of ASP.NET allows more functional freedom and greater flexibility for the programmers.
Databinding, templates and creation of customized columns in ASP.NET requires one to use Eval and Bind methods in order to bind controls. The usage of Eval method is for read-only purposes, which means that a user can only control the display values. The Bind method on the other hand allows the users to modify and update data – the values entered in a column can be changed or altered through TextBox and CheckBox controls. This is the basic difference between Eval and Bind – a template can be edited, changed, modified or deleted with the usage of Bind method, whereas the Eval method allows one to only enter the desired values.
Databinding syntax allows users to insert, modify, alter, change, retrieve or delete data from a template or column on a webpage. The data expression in the controls such as FormView, GridView etc. can be evaluated using the Eval method, which allows for binding only inside a data-bound control. The data values can be retrieved with the Eval method – they cannot be modified or deleted. The Bind method on the other hand allows for the data-bound controls to be modified in addition to retrieval, and hence is preferred over Eval method.