C#合并BitMap图像如何生成超大bitmap

这篇文章主要介绍C#合并BitMap图像如何生成超大bitmap，文中介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们一定要看完！

当只需要两个图像合并的时候，可以简单的使用gdi+，把两个图像画到一个画布上面实现合并bitmap.

当需要将许多bitmap合并时，由于bitmap类限制，长度或宽度太大时会报异常，前面这种方法就行不通了。

由于bitmapp属于位图格式，了解图像格式后，发现，bitmap文件的第3-8位存储了文件大小信息，第19-22位存储了高度信息，第23-26位存储了宽度信息。文件头后面都是像素的argb，并无其它信息。于是，试想一下，如果把第二张图像的像素argb放到第一张后面，并修改第一张的文件头信息，是不是就可以实现文件合并了呢。事实证明：yes。

//设置文件头里面文件大小信息public void SetBitmapFileSizeInfo(string filePath)        {            FileInfo fileInfo = new FileInfo(filePath);            long le = fileInfo.Length;            string hexSize = le.ToString("X").PadLeft(8, '0');            int size1 = Convert.ToInt32(hexSize.Substring(0, 2), 16);            int size2 = Convert.ToInt32(hexSize.Substring(2, 2), 16);            int size3 = Convert.ToInt32(hexSize.Substring(4, 2), 16);            int size4 = Convert.ToInt32(hexSize.Substring(6, 2), 16);            byte[] sizeBytes = new byte[] { (byte)size4, (byte)size3, (byte)size2, (byte)size1 };            using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Write))            {                using (BinaryWriter r = new BinaryWriter(fs))                {                    r.Seek(2, 0);                    r.Write(sizeBytes, 0, sizeBytes.Length);                }            }        }

设置文件头里面文件长度和宽度信息

 public void SetBitmapSizeInfo(string filePath,int width=0,int height=0)        {            if (height != 0)            {                string hexHeight = height.ToString("X").PadLeft(8, '0');                int h2 = Convert.ToInt32(hexHeight.Substring(0, 2), 16);                int h3 = Convert.ToInt32(hexHeight.Substring(2, 2), 16);                int h4 = Convert.ToInt32(hexHeight.Substring(4, 2), 16);                int h5 = Convert.ToInt32(hexHeight.Substring(6, 2), 16);                byte[] sizeHeight = new byte[] { (byte)h5, (byte)h4, (byte)h3, (byte)h2 };                using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.ReadWrite))                {                    using (BinaryWriter r = new BinaryWriter(fs))                    {                        r.Seek(22, 0);//高度保存位置                        r.Write(sizeHeight, 0, sizeHeight.Length);                    }                }            }            if (width != 0)            {                string hexWidth = height.ToString("X").PadLeft(8, '0');                int w1 = Convert.ToInt32(hexWidth.Substring(0, 2), 16);                int w2 = Convert.ToInt32(hexWidth.Substring(2, 2), 16);                int w3 = Convert.ToInt32(hexWidth.Substring(4, 2), 16);                int w4 = Convert.ToInt32(hexWidth.Substring(6, 2), 16);                byte[] sizeWidth = new byte[] { (byte)w4, (byte)w3, (byte)w2, (byte)w1 };                using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.ReadWrite))                {                    using (BinaryWriter r = new BinaryWriter(fs))                    {                        r.Seek(18, 0);//高度保存位置                        r.Write(sizeWidth, 0, sizeWidth.Length);                    }                }            }        }

合并多个bitmap文件,并生成一个最终文件

private void CreateBitMap(string tempPath,string imagePath)        {            string[] files = Directory.GetFiles(tempPath, "*.png");            Bitmap bmp;            int height=0;            for (int i = files.Length-1; i >0; i--)            {                string fileName = files[i];                bmp = new Bitmap(fileName);                if (i == files.Length - 1)                {                    bmp.Save(imagePath, ImageFormat.Bmp);                    height += bmp.Height;                    bmp.Dispose();                    continue;                }                else                {                    byte[] bytes = GetImageRasterBytes(bmp, PixelFormat.Format32bppRgb);                    using (FileStream fs = new FileStream(imagePath, FileMode.Open, FileAccess.Write))                    {                        fs.Seek(fs.Length, 0);                        fs.Write(bytes, 0, bytes.Length);                    }                    height += bmp.Height;                    bmp.Dispose();                }            }            SetBitmapFileSizeInfo(imagePath);            SetBitmapSizeInfo(imagePath, height: height);            //MessageBox.Show("合并成功");        }         private static byte[] GetImageRasterBytes(Bitmap bmp, PixelFormat format)        {            Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height);            byte[] bits = null;            try            {                // Lock the managed memory                BitmapData bmpdata = bmp.LockBits(rect, ImageLockMode.ReadWrite, format);                // Declare an array to hold the bytes of the bitmap.                bits = new byte[bmpdata.Stride * bmpdata.Height];                // Copy the values into the array.                System.Runtime.InteropServices.Marshal.Copy(bmpdata.Scan0, bits, 0, bits.Length);                // Release managed memory                bmp.UnlockBits(bmpdata);            }            catch            {                return null;            }            return bits;        }

以上是"C#合并BitMap图像如何生成超大bitmap"这篇文章的所有内容，感谢各位的阅读！希望分享的内容对大家有帮助，更多相关知识，欢迎关注行业资讯频道！