Microsoft Technology Development (.Net)

How to create Dynamic Where Clause in Linq

2011-01-13T07:11:00.000-08:00

C# Method:

public IQueryable GetProductList(string whereClause)
    {
        var query = context.ItemMaster_Stage
                              .Where(whereClause);

        return (IQueryable)query;
    }

Method calling:

IQueryable obj = new Products().GetProductList("it.ITEM_NAME == 'WEDDING BANDS'");

Here you can call this method with 'Where' clause as per your requirement.

Linq To Sql return from function as IQueryable

2011-01-12T05:25:00.000-08:00

Following is the example illustrating how we can return IQueryable<T> from a method which has linq to SQL statements and bind returned data to a asp.net repeater control:

public IQueryable GetParentCategory()
    {
        return (context.CategoryMaster
           .Where(c => c.PARENT_CATEGORY_ID == 0)
           .Select(c => new { c.PARENT_CATEGORY_ID, c.CATEGORY_NAME, c.CATEGORY_ID })).AsQueryable();
    }

In above example we need only three fields (Projection) from data source.

We can bind repeater with following code:

rptParentCategory.DataSource = new Products().GetParentCategory();
rptParentCategory.DataBind();

Here 'Product' is a class in 'App_code' containing method 'GetParentCategory'.

JS Function to 'SELECT ALL' / 'CLEAR ALL' for CheckBoxList Control

2009-12-16T06:29:00.001-08:00

JS FUNCTION:

function CheckBoxListSelect(cbControl, state)
   {
   var chkBoxList = document.getElementById(cbControl);
   var chkBoxCount= chkBoxList.getElementsByTagName("input");
   for(var i=0;i<chkBoxCount.length;i++)
   {
   chkBoxCount[i].checked = state;
   }
   return false;
   }

ASP.Net Repeater: checkbox validation using javascript

2009-12-11T02:28:00.000-08:00

Javascript function for validating checkbox:

The repeater control has two chechbox.
Following function will warn user if he selects second checkbox without selecting first checkbox.

function ValidateCB(cb2)
{

//Get the object for Second Check box (Control ID is passed in method : this.id)
var cbSecondID = document.getElementById(cb2);

//Contruct Control ID for First CheckBox, by replacing string (control id of second checkbox)
var cbFirstID = cbSecondID.id.replace("cb2","cb1");

//Get the object for first checkbox
var cbFirst = document.getElementById(cbFirstID);

//displays alert when first cb is not selected and we are attampting to select second one
if (cbSecondID.checked == true && cbFirst.checked == false)
{
alert("Please select first checkbox");
}

}