A read-only field that represents a pointer or handle that has been initialized to zero.
Value: 0
Syntax
Remarks
The value of this field is not equivalent to null. Use this field to efficiently determine whether an instance of IntPtr has been set to a value other than zero.
For example, assume the variable, ip, is an instance of IntPtr. You can determine if it has been set by comparing it to the value returned by a constructor, for example: " if ip != new IntPtr(0)... ". However, invoking a constructor to get an unintialized pointer is inefficient. It is better to code either " if ip != IntPtr.Zero... ", or " if !IntPtr.Zero.Equals(ip)... ".
When calling the Windows API from managed code, you can pass IntPtr.Zero instead of null if an argument is expected to be either a pointer or a null. For example, the following call to the Windows CreateFile function supplies IntPtr.Zero for the pSecurityAttributes and hTemplateFile argument values.
code reference: System.IntPtr.Zero#2
Although IntPtr.Zero is equivalent to null for Windows API functions with parameters or return values that can be either pointers or null, IntPtr.Zero is not equivalent to null. Passing null to the IntPtr.Zero.Equals method always returns false.
You can also test for a null return value from Windows API function calls that return either a pointer or a null by comparing the returned value with IntPtr.Zero. For example, the call to the GetWindow function in the following example tries to retrieve the handle of a non-existent window. If it were called from unmanaged code, the function would return null, but when it is called from managed code, it returns IntPtr.Zero.
code reference: System.IntPtr.Zero#1
Requirements
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0