xamarin.forms 版本自動更新(針對android）

1.首先同過url位址下載下傳檔案，這裡必須要啟用單獨一個下載下傳線程

 new Thread(run).Start();

通過url下載下傳的方法

 public void run()

        {

            int receivedBytes = 0;

            int totalBytes = 0;

            string dirPath = "/sdcard/updateVersion/version";

            var filePath = Path.Combine(dirPath, "hz_android.apk");

            URL url = new URL(urlToDownload);//urlToDownload 下載下傳檔案的url位址

            HttpURLConnection conn = (HttpURLConnection)url.OpenConnection();

            conn.Connect();

            Stream Ins = conn.InputStream;

            totalBytes = conn.ContentLength;

            if (!Directory.Exists(dirPath))

            {

                Directory.CreateDirectory(dirPath);

            }

            else

                if (File.Exists(filePath))

                {

                    File.Delete(filePath);

                }

            using (FileStream fos = new FileStream(filePath, FileMode.Create))

                byte[] buf = new byte[512];

                do

                    int numread = Ins.Read(buf, 0, 512);

                    receivedBytes += numread;

                    if (numread <= 0)

                    {

                        break;

                    }

                    fos.Write(buf, 0, numread);

//進度條代碼

                    if (progessReporter != null)

                        DownloadBytesProgress args = new DownloadBytesProgress(urlToDownload, receivedBytes, totalBytes);

                        progessReporter.Report(args);

                } while (true);

//調用下載下傳的檔案進行安裝

            installApk(filePath);

        }

 private void installApk(string filePath)

            var context = Forms.Context;

            if (context == null)

                return;

            // 通過Intent安裝APK檔案

            Intent intent = new Intent(Intent.ActionView);

            intent.SetDataAndType(Uri.Parse("file://" + filePath), "application/vnd.android.package-archive");

            //Uri content_url = Uri.Parse(filePath);

            //intent.SetData(content_url);

            intent.SetFlags(ActivityFlags.NewTask);

            context.StartActivity(intent);