Gets a value indicating whether the FileUpload control contains a file.
Assembly: System.Web (in System.Web.dll)
The property gets a value indicating whether the FileUpload control contains a file to upload. Use this property to verify that a file to upload exists before performing operations on the file. For example, before calling the SaveAs method to save the file to disk, use the property to verify that the file exists. If returns true, call the SaveAs method. If it returns false, display a message to the user indicating that the control does not contain a file.
The following example demonstrates how to create a FileUpload control that performs error checking. Before saving the file, the method is called to verify that the control contains a file to upload. In addition, the File.Exists method is called to check whether a file with the same name already occurs in the path. If it does, the name of the file to upload is prefixed with an underscore character before the SaveAs method is called. This prevents the existing file from being overwritten.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.