手动加载位图

我正在尝试编写一些C＃代码，该代码将使用位于磁盘上的.bmp命名。为此，我一直在关注Wikipedia页面：BMP文件格式

所以我创建了2个类来包含标题。首先是文件头：

    class BMPFileHeader
    {
        public BMPFileHeader(Byte[] headerBytes)
        {
            // Position
            int offset = 0;

            // Read 2 byes
            bfType = ((char)headerBytes[0]).ToString();
            bfType += ((char)headerBytes[1]).ToString();
            offset = offset + 2;
            // Read 4 bytes to uint32
            bfSize = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);

            // Read 2 bytes to uint16
            bfReserved1 = BitConverter.ToUInt16(headerBytes, offset);
            offset = offset + sizeof(UInt16);

            // Read 2 bytes to uint16
            bfReserved2 = BitConverter.ToUInt16(headerBytes, offset);
            offset = offset + sizeof(UInt16);

            // Read 4 bytes to uint32
            bfOffBits = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);
        }

        public string bfType;                      // Ascii characters "BM"
        public UInt32 bfSize;                      // The size of file in bytes
        public UInt16 bfReserved1;                 // Unused, must be zero
        public UInt16 bfReserved2;                 // Same ^^
        public UInt32 bfOffBits;                   // Pixel offset [ where pixel array starts ]
    }

这似乎工作得很好。因此，转到下一个标题，即图像标题。：

    class BMPImageHeader
    {
        public BMPImageHeader(Byte[] headerBytes)
        {
            // Position
            int offset = 0;

            biSize = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);

            biWidth = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);

            biHeight = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);

            biPlanes = BitConverter.ToUInt16(headerBytes, offset);
            offset = offset + sizeof(UInt16);

            biBitCount = BitConverter.ToUInt16(headerBytes, offset);
            offset = offset + sizeof(UInt16);

            biCompression = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);

            biSizeImage = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);

            XPelsPerMeter = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);

            YPelsPerMeter = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);

            biClrUsed = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);

            biClrImportant = BitConverter.ToUInt32(headerBytes, offset);
            offset = offset + sizeof(UInt32);
        }

        public UInt32 biSize;          // Size of header, must be least 40
        public UInt32 biWidth;         // Image width in pixels
        public UInt32 biHeight;        // Image height in pixels
        public UInt16 biPlanes;        // Must be 1
        public UInt16 biBitCount;      // Bits per pixels.. 1..4..8..16..32    
        public UInt32 biCompression;   // 0 No compression
        public UInt32 biSizeImage;     // Image size, may be zer for   uncompressed
        public UInt32 XPelsPerMeter;   // Preferred resolution in pixels per meter
        public UInt32 YPelsPerMeter;   // Same ^^
        public UInt32 biClrUsed;       // Number color map entries
        public UInt32 biClrImportant;  // Number of significant colors


    }

这似乎也可行。.所以现在我有一些重要的信息来显示这张照片。

biBitCount = bits per pixel
biHeight = height in pixel
biWidth  = width in pixel
bfOffBit = Pixel array offset

因此，作为一个聪明的人，我以为我是。我将开始将它们复制到我创建的包含3个字节的struct 2D数组中。红色，绿色和蓝色。因此，将文件的所有其余部分读取到缓冲区中。然后一次通过该缓冲区3个字节，并添加一个由这3个字节组成的像素。

    public ImageManipulation(string _name, string _imageLocation)
    {
        // Set name
        Name = _name;

        // Initialize classes
        //fHeader = new BMPFileHeader();
        //iHeader = new BMPImageHeader();

        if (File.Exists(_imageLocation))
        {
            int offset = 0;
            Byte[] fsBuffer;
            FileStream fs = File.Open(_imageLocation, FileMode.Open, FileAccess.Read);

            // Start by reading file header..
            fsBuffer = new Byte[14]; // size 40 bytes
            fs.Read(fsBuffer, 0, 14);
            fHeader = new BMPFileHeader(fsBuffer);

            // Then image header, 40 bytes
            fsBuffer = new Byte[40];
            fs.Read(fsBuffer, 0, 40);
            iHeader = new BMPImageHeader(fsBuffer);

            // Apply pixels
            Pixels = new RGBPixel[iHeader.biHeight, iHeader.biWidth];

            // How many bytes per pixel
            int bpi = iHeader.biBitCount/8;

            // Read pixel array
            long totalBytes = iHeader.biWidth*iHeader.biHeight*bpi;

            if (totalBytes == iHeader.biSizeImage) ;
            if (iHeader.biSizeImage == ( fHeader.bfSize - (iHeader.biSize + 14))) ;

            // Create butter, read data
            fsBuffer = new Byte[iHeader.biWidth*iHeader.biHeight*bpi];
            fs.Read(fsBuffer, 0, (int)fHeader.bfOffBits);

            int RowSize = ((iHeader.biBitCount *(int) iHeader.biWidth + 31) / 32) * 4;


            int x, y;
            x = y = 0;

            long i;
            int lcounter = 0;

            // This reads 3 bytes a time 
            for (i = 0; i < totalBytes; i = i + 3)
            {
                    // Read 3 bytes
                    Pixels[ (iHeader.biHeight-1) - y, x].RED = fsBuffer[i];
                    Pixels[ (iHeader.biHeight-1) - y, x].GREEN = fsBuffer[i + 1];
                    Pixels[ (iHeader.biHeight-1) - y, x].BLUE = fsBuffer[i + 2];

                    // Update position in array
                    x++;
                    if (x == iHeader.biWidth)
                    {
                        y++;
                        x = 0;
                    }
            }
        }
    }   

我在运行和编译此代码时没有任何错误，但是后来我用Bitmap.setPixel（）创建的图像几乎只是黑色的。所以我以某种方式读取像素错误，但我无法确定原因？？

我用来测试的图像是

我得到的是：

谢谢任何帮助表示赞赏