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LoadImage (user32)
 
.
Summary

C# Signature:

[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern IntPtr LoadImage(IntPtr hinst, string lpszName, uint uType,
   int cxDesired, int cyDesired, uint fuLoad);

VB Signature:

<DllImport("user32.dll", SetLastError:=True)> _
Private Shared Function LoadImage(ByVal hInst As IntPtr, ByVal lpszName As String, ByVal uType As UInt32, _
ByVal cxDesired As Integer, ByVal cyDesired As Integer, ByVal fuLoad As UInt32) As IntPtr
End Function

C++/CLI Signature:

[DllImportAttribute("user32.dll", SetLastError = true, CharSet = CharSet::Auto)]
extern "C" int LoadImage(int hinst, int lpszName, unsigned int uType, int cxDesired, int cyDesired, unsigned int fuLoad);

User-Defined Types:

None.

User-Defined Constants:

IMAGE_

LR_

Notes:

C++/CLI: This solution allows you to load an image from an unmanaged resource in the assembly. In my case I added a .cur file to my .rc. The cursor had an ID of 101. After loading the cursor I assigned it to the Forms::Cursor.

Tips & Tricks:

To use integer resource ID instead of string, and avoid using MAKEINTRESOURCE, prepend the integer with '#'. For example, to use resource ID 32512, enter "#32512" for lpszName.

To load application icons of different sizes, use cxDesired and cyDesired (see the example).

Sample Code:

Please add some!

C++/CLI Example

using namespace System::Runtime::InteropServices;
using namespace System::Windows::Forms;
using namespace System::Reflection;

int a = LoadImage(Marshal::GetHINSTANCE(Assembly::GetExecutingAssembly()->GetModules()[0]).ToInt32(),101,2,0,0,0);
this->Cursor = gcnew ::Cursor(IntPtr(a));

Sample Code (C#):

namespace ITLN.Utils.GUI {

Alternative Managed API:

System.Drawing.Image.FromFile

    // http://www.itln.pl
    public static class AuxiliaryGUIIcon {

- or to load an image from a managed resource (dll):

System.Drawing.Bitmap.FromResource

        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        private static extern IntPtr LoadImage(IntPtr hinst, string lpszName, uint uType,
            int cxDesired, int cyDesired, uint fuLoad);

Documentation

        [DllImport("user32.dll", SetLastError = true)]
        private static extern int DestroyIcon(IntPtr hIcon);

        [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        private static extern IntPtr LoadLibraryEx(string lpFileName, IntPtr hFile, LoadLibraryFlags dwFlags);

        private enum LoadLibraryFlags : uint {
            DONT_RESOLVE_DLL_REFERENCES = 0x00000001,
            LOAD_IGNORE_CODE_AUTHZ_LEVEL = 0x00000010,
            LOAD_LIBRARY_AS_DATAFILE = 0x00000002,
            LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE = 0x00000040,
            LOAD_LIBRARY_AS_IMAGE_RESOURCE = 0x00000020,
            LOAD_WITH_ALTERED_SEARCH_PATH = 0x00000008
        }

        /// <summary>
        /// Returns an icon of given size.
        /// </summary>
        /// <param name="path">Path to a file (.exe/.dll) that contains the icons.
        ///        Skip it or use <c>null</c> to use current application's file.</param>
        /// <param name="resId">Name of the resource icon that should be loaded.
        ///        Skip it to use the default <c>#32512</c> (value of <c>IDI_APPLICATION</c>) to use
        ///        the application's icon.</param>
        /// <param name="size">Size of the icon to load. If there is no such size available, a larger or smaller
        ///        sized-icon is scaled.</param>
        /// <returns>List of all icons.</returns>
        public static Icon GetIconFromExe(string path = null, string resId = "#32512", int size = 32) {
            // load module
            IntPtr h;
            if (path == null)
                h = Marshal.GetHINSTANCE(Assembly.GetEntryAssembly().GetModules()[0]);
            else {
                h = LoadLibraryEx(path, IntPtr.Zero, LoadLibraryFlags.LOAD_LIBRARY_AS_DATAFILE);
                if (h == IntPtr.Zero)
                    return null;
            }

            // 1 is IMAGE_ICON
            IntPtr ptr = LoadImage(h, resId, 1, size, size, 0);
            if (ptr != IntPtr.Zero) {
                try {
                    Icon icon = (Icon)Icon.FromHandle(ptr).Clone();
                    return icon;
                } finally {
                    DestroyIcon(ptr);
                }
            }
            return null;
        }
    }
}

Alternative Managed API:

System.Drawing.Image.FromFile

- or to load an image from a managed resource (dll):

System.Drawing.Bitmap.FromResource

Documentation

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