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MSDN Library

DllImportAttribute Constructor

Initializes a new instance of the DllImportAttribute class with the name of the DLL containing the method to import.

Namespace:  System.Runtime.InteropServices
Assemblies:   mscorlib (in mscorlib.dll)
  System.Runtime.InteropServices (in System.Runtime.InteropServices.dll)

public DllImportAttribute(
	string dllName
)

Parameters

dllName
Type: System.String

The name of the DLL that contains the unmanaged method. This can include an assembly display name, if the DLL is included in an assembly.

If an unmanaged DLL file is included in an assembly, for example, by using the linker or the /linkresource compiler option, you can specify the assembly display name as part of dllName. For example, if an unmanaged DLL named unmanaged.dll is included in a managed assembly named MyAssembly, the attribute might be specified as shown in the following code.

[DllImport("unmanaged.dll, MyAssembly, Version= 1.0.0.0," +
 "Culture=neutral, PublicKeyToken=a77e0ba5eab10125")]
static extern int SomeFuncion1(int parm);

The following code example shows how to use the DllImportAttribute attribute to import the Win32 MessageBox function. The code example then calls the imported method.

using System;
using System.Runtime.InteropServices;

class Example
{
    // Use DllImport to import the Win32 MessageBox function.
    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
    public static extern int MessageBox(IntPtr hWnd, String text, String caption, uint type);

    static void Main()
    {
        // Call the MessageBox function using platform invoke.
        MessageBox(new IntPtr(0), "Hello World!", "Hello Dialog", 0);
    }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
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