C# MJPEG 客戶端簡單實現方法

//創建一個HTTP請求,隻要請求不結束，MJPEG服務端會一直給請求的響應體中發送實時圖片內容
HttpWebRequest hwRequest = (System.Net.HttpWebRequest)WebRequest.Create("請求URL地址");
hwRequest.Method = "GET";
HttpWebResponse hwResponse = (HttpWebResponse)hwRequest.GetResponse();
//讀boundary指定的每張圖片分隔符,DroidCam為:--dcmjpeg
string contentType = hwResponse.Headers["Content-Type"];
string boundryKey = "boundary=";
string boundary = contentType.Substring(contentType.IndexOf(boundryKey) + boundryKey.Length);
 
//拿到響應體流
Stream stream = hwResponse.GetResponseStream();
string headerName = "Content-Length:";
//臨時存儲字符串數據
StringBuilder sb = new StringBuilder();
int len = 1024;
while (true)
{
    //讀取一行數據
    while (true) {
        char c = (char)stream.ReadByte();
        //Console.Write(c);
        if (c == '\n') {
            break;
        }
        sb.Append(c);
    }
    string line = sb.ToString();
    sb.Remove(0, sb.Length);
    //當前行中是否包含Content-Length:
    int i = line.IndexOf(headerName);
    if (i != -1) {
        //每張圖片前有一段圖片簡單介紹(圖片類型、長度),這裡隻關心長度(Content-Length:)後邊的值，用於後續讀取圖片
        int imageFileLength = Convert.ToInt32(line.Substring(i + headerName.Length).Trim());
        //Content-Length:xxx 完後會有一個/r/n的換行符，換行符後才是真正的圖片數據(不知道是DroidCam自己這樣還是都這樣...)
        //這裡跳過/r/n
        stream.Read(new byte[2], 0, 2);
        //開始讀取圖片數據,imageFileLength就是讀到的Content-Length:後的長度
        byte[] imageFileBytes = new byte[imageFileLength];
        stream.Read(imageFileBytes, 0, imageFileBytes.Length);
        //JPEG的文件頭是: FF D8 FF ，文件尾是: FF D9，非常重要，調試時最好打印一下，便於區分讀入的數據是否正好時圖片的所有內容
        //Console.WriteLine("文件頭:" + imageFileBytes[0].ToString("X") + " " + imageFileBytes[1].ToString("X") + " " + imageFileBytes[2].ToString("X") + " " + imageFileBytes[3].ToString("X") + " " + imageFileBytes[4].ToString("X"));
        //Console.WriteLine("文件尾:" + imageFileBytes[imageFileLength - 2].ToString("X") + " " + imageFileBytes[imageFileLength - 1].ToString("X"));
        //此處做瞭一個如果讀入文件不全時處理,圖片越大,程序循環讀取速度越快，越有可能導致讀取文件不全情況...，如果有好的辦法解決希望前輩們指教,非常感謝!
        //文件尾是否是FF D9
        if (imageFileBytes[imageFileLength - 2].ToString("X") != "FF" && imageFileBytes[imageFileLength - 1].ToString("X") != "D9")
        {
            //讀入文件內容不全，跳過次文件,讓流位置跳到下次圖片開始位置
            //Console.WriteLine("開始矯正...");
            char l = '0';
            while (true)
            {
                char c = (char)stream.ReadByte();
                //這裡隻判斷瞭--dcmjpeg中的前兩個字符--,當讀到的流中連續兩個字符是--時，表示流已讀到下次圖片開始位置
                if (l == boundary[0] && c == boundary[1])
                {
                    break;
                }
                l = c;
            }
        }
        else
        {
            //讀取圖片成功!
            //accessImageHandler是一個Action,用於把圖片實時寫到PictureBox控件中
            accessImageHandler(imageFileBytes);
        }
        //這裡適當睡幾十毫秒，會降低點圖片讀入不全情況,還未找到圖片隨機讀取不全情況原因...
        Thread.Sleep(sleep);
    }
}
stream.Close();
hwResponse.Close();

hwRequest.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(Encoding.UTF8.GetBytes(user + ":" + pass)));