Equivalent of CType in C# to convert Dropdownlist which is in EditItemTemplate of Gridview

Question

Hi, I am using a Gridview to display some data. In EditItemTemplate of gridview I am using DropDownList for one of the column of gridview. DataSource of gridview is a table "UserEntries". And Datasource of Dropdown is another table "TypeEntries". Columns of TypeEntries are - Guid and TypeName. Guid is DataValueField of dropdown and TypeName is DataTextField. I am storing DataValueFiels of dropdown in UserEntries table.

Now when user clicks Edit button of gridview, how to populate dropdown with "TypeEntries" table? I am using

    Dropdownlist tempddl = new Dropdownlist();
    tempddl = (Dropdownlist)gvUserData.FindControl("ddlTypeListInGrid");
    tempddl.DataSource = _section.GetTypeEntries();
    tempddl.DataBind();

but it is not working. Can anyone tell me any other way to do this task? Thanks in advance.

Answer 1

C# is case sensitive, you should use DropDownList instead.

Answer 2

Are you looking for Convert.ChangeType, I would have to see more code to get at your problem.

Answer 3

I am uploading whole code of function.

protected void gvUserData_OnRowEditing(object sender, GridViewEditEventArgs  e)
{
    gvUserData.EditIndex = e.NewEditIndex;

    gvUserData.DataSource = _section.GetUserEntries();
    gvUserData.DataBind();

    DropDownList tempddl = new DropDownList();       //I am not sure whether this is correct or not..        
    tempddl = (DropDownList)gvUserData.FindControl("ddlTypeListInGrid");
    tempddl.DataSource = _section.GetTypeEntries();
    tempddl.DataBind();        

}

Answer 4

If you get "Object reference not set to an instance of an object." in exception, it means the "ddlTypeListInGrid" control was not found. So you can not cast NULL ( NOTHING ) to target type.

You propably do this code in wrogn page's life cycle. Try it in one of later oage events (Load, LoadComplete, etc..) or check, if the container realy contains control with ID "ddlTypeListInGrid".

Answer 5

As a side note ( not related with your problem, just for your information ) the folowing line :

 DropDownList tempddl = new DropDownList();

Could be :

 DropDownList tempddl;

You dont need to create a new instance of DropDownList since at the next line, your tryng to find an instance nammed "ddlTypeListInGrid". Then, as Tcks said, if the ddlTypeListInGrid control does not exist, then you will likely get a NullReferenceException.