How to use IndexOf() method of List <object> asp net c#

var index = students.FindIndex(st => st.ID == student.ID);

Using DataBinder.Eval in the RowDataBound Event asp net gridview

decimal totalAmount = 0;
protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
 totalAmount += Decimal.Parse(DataBinder.Eval(e.Row.DataItem, "Amount").ToString());
}
}

Cannot generate deployment plan SSDT

Delete the .dbmdl file in your database project.

Getting relative virtual path from physical path asp net c#

var relativePath = "/" + physicalPath.Replace(HttpContext.Current.Request.PhysicalApplicationPath, String.Empty).Replace("\\", "/");

Or use the extension method

/// <summary>
/// Get relative path from physical path
/// </summary>
/// <param name="di">DirectoryInfo</param>
/// <returns></returns>
public static string GetRelativePath(this DirectoryInfo di)
{
 return "/" + di.FullName.Replace(HttpContext.Current.Request.PhysicalApplicationPath, String.Empty).Replace("\\", "/");
}

O/R Designer validation failed for file: .dbml

devenv.exe /ResetSkipPkgs