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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
namespace Windows.Win32.Graphics.Gdi;
/// <summary>
/// Helper to scope lifetime of a <see cref="Gdi.HBITMAP"/> created via <see cref="PInvokeCore.CreateBitmap"/>
/// Deletes the <see cref="Gdi.HBITMAP"/> (if any) when disposed.
/// </summary>
/// <remarks>
/// <para>
/// Use in a <see langword="using" /> statement. If you must pass this around, always pass
/// by <see langword="ref" /> to avoid duplicating the handle and risking a double delete.
/// </para>
/// </remarks>
#if DEBUG
internal class CreateBitmapScope : DisposalTracking.Tracker, IDisposable
#else
internal readonly ref struct CreateBitmapScope
#endif
{
public HBITMAP HBITMAP { get; }
/// <summary>
/// Creates a bitmap using <see cref="PInvokeCore.CreateBitmap"/>
/// </summary>
public unsafe CreateBitmapScope(int nWidth, int nHeight, uint nPlanes, uint nBitCount, void* lpvBits) =>
HBITMAP = PInvokeCore.CreateBitmap(nWidth, nHeight, nPlanes, nBitCount, lpvBits);
/// <summary>
/// Creates a bitmap compatible with the given <see cref="HDC"/> via
/// <see cref="PInvokeCore.CreateCompatibleBitmap(HDC, int, int)"/>
/// </summary>
public CreateBitmapScope(HDC hdc, int cx, int cy) => HBITMAP = PInvokeCore.CreateCompatibleBitmap(hdc, cx, cy);
public static implicit operator HBITMAP(in CreateBitmapScope scope) => scope.HBITMAP;
public static implicit operator HGDIOBJ(in CreateBitmapScope scope) => scope.HBITMAP;
public static explicit operator nint(in CreateBitmapScope scope) => scope.HBITMAP;
public bool IsNull => HBITMAP.IsNull;
public void Dispose()
{
if (!HBITMAP.IsNull)
{
PInvokeCore.DeleteObject(HBITMAP);
}
#if DEBUG
GC.SuppressFinalize(this);
#endif
}
}
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