如何将 CF_DIBV5 转换为 BitmapSource？

Question

我希望将剪贴板中的CF_DIBV5 格式转换为BitmapSource 对象。到目前为止，这是我的代码，基于我以前用于将普通 DIB 转换为 BitmapSource 的代码。要转换普通的 DIB，我发现我只需要获取标头，并将其添加到位图的原始字节之前。

不幸的是，当我尝试使代码兼容 DIBV5 时，程序现在抛出以下异常。

找不到适合完成此操作的成像组件。

当我使用BitmapFrame 的Create 方法时会发生这种情况。完整代码如下。

var infoHeader =
    ApiHelper.ByteArrayToStructure<BITMAPV5HEADER>(buffer);

var fileHeaderSize = Marshal.SizeOf(typeof(BITMAPV5HEADER));
var infoHeaderSize = infoHeader.bV5Size;
var fileSize = fileHeaderSize + infoHeader.bV5Size + infoHeader.bV5SizeImage;

var fileHeader = new BITMAPV5HEADER();
fileHeader.bV5CSType = BITMAPV5HEADER.LCS_sRGB;
fileHeader.bV5Size = (uint) fileSize;
fileHeader.bV5Reserved = 0;

byte[] fileHeaderBytes =
    ApiHelper.StructureToByteArray(fileHeader);

var bitmapStream = new MemoryStream();
bitmapStream.Write(fileHeaderBytes, 0, fileHeaderSize);
bitmapStream.Write(buffer, 0, buffer.Length);
bitmapStream.Seek(0, SeekOrigin.Begin);

BitmapFrame bitmap = BitmapFrame.Create(bitmapStream);

关于我做错了什么，或者我做错了什么的任何想法？我在盲目地摸索，不幸的是，对于像我这样的 C# 程序员来说，文档很少。我懂一点 C++，但不足以从 C++ 转换为 C#。

Answer 1

将此image 复制到剪贴板。您还需要将 Image 控件添加到 MainWindow。这需要一段时间才能弄清楚，所以我可能错过了添加所需参考的解释。

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media;
using System.Windows.Media.Imaging;

namespace WpfApp1
{
    public partial class MainWindow : Window
    {
        [DllImport("User32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool IsClipboardFormatAvailable(uint format);

        [DllImport("User32.dll", SetLastError = true)]
        private static extern IntPtr GetClipboardData(uint uFormat);

        [DllImport("User32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool OpenClipboard(IntPtr hWndNewOwner);

        [DllImport("User32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool CloseClipboard();

        [DllImport("Kernel32.dll", SetLastError = true)]
        private static extern IntPtr GlobalLock(IntPtr hMem);

        [DllImport("Kernel32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool GlobalUnlock(IntPtr hMem);

        const uint CF_DIBV5 = 17;

        public enum BitmapCompressionMode : uint
        {
            BI_RGB = 0,
            BI_RLE8 = 1,
            BI_RLE4 = 2,
            BI_BITFIELDS = 3,
            BI_JPEG = 4,
            BI_PNG = 5
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct BITMAPV5HEADER
        {
            public uint bV5Size;
            public int bV5Width;
            public int bV5Height;
            public UInt16 bV5Planes;
            public UInt16 bV5BitCount;
            public uint bV5Compression;
            public uint bV5SizeImage;
            public int bV5XPelsPerMeter;
            public int bV5YPelsPerMeter;
            public UInt16 bV5ClrUsed;
            public UInt16 bV5ClrImportant;
            public UInt16 bV5RedMask;
            public UInt16 bV5GreenMask;
            public UInt16 bV5BlueMask;
            public UInt16 bV5AlphaMask;
            public UInt16 bV5CSType;
            public IntPtr bV5Endpoints;
            public UInt16 bV5GammaRed;
            public UInt16 bV5GammaGreen;
            public UInt16 bV5GammaBlue;
            public UInt16 bV5Intent;
            public UInt16 bV5ProfileData;
            public UInt16 bV5ProfileSize;
            public UInt16 bV5Reserved;
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        public struct RGBQUAD
        {
            public byte rgbBlue;
            public byte rgbGreen;
            public byte rgbRed;
            public byte rgbReserved;
        }

        public MainWindow()
        {
            InitializeComponent();
            AttemptConversion();
        }

        private void AttemptConversion()
        {
            WindowInteropHelper helper = new WindowInteropHelper(this);

            bool gotIt = OpenClipboard(helper.Handle);
            if (!gotIt) return;

            bool formatAvail = IsClipboardFormatAvailable(CF_DIBV5);
            if (!formatAvail) return;

            IntPtr hBitmap = IntPtr.Zero;
            hBitmap = GetClipboardData(CF_DIBV5);
            IntPtr ptr = GlobalLock(hBitmap);

            BitmapSource bmpSrc = CF_DIBV5ToBitmapSource(hBitmap);

            img.Width = (int)bmpSrc.Width;
            img.Height = (int)bmpSrc.Height;
            img.Source = bmpSrc;

            if (ptr != IntPtr.Zero) GlobalUnlock(hBitmap);
            if (gotIt) CloseClipboard();
        }

        private BitmapSource CF_DIBV5ToBitmapSource(IntPtr hBitmap)
        {
            IntPtr scan0 = IntPtr.Zero;
            var bmi = (BITMAPV5HEADER)Marshal.PtrToStructure(hBitmap, typeof(BITMAPV5HEADER));

            int stride = (int)(bmi.bV5SizeImage / bmi.bV5Height);
            long offset = bmi.bV5Size + bmi.bV5ClrUsed * Marshal.SizeOf<RGBQUAD>();
            if (bmi.bV5Compression == (uint)BitmapCompressionMode.BI_BITFIELDS)
            {
                offset += 12; //bit masks follow the header
            }
            scan0 = new IntPtr(hBitmap.ToInt64() + offset);

            BitmapSource bmpSource = BitmapSource.Create(
                bmi.bV5Width, bmi.bV5Height,
                bmi.bV5XPelsPerMeter, bmi.bV5YPelsPerMeter,
                PixelFormats.Bgra32, null,
                scan0, (int)bmi.bV5SizeImage, stride);

            return bmpSource;
        }
    }
}