主要原理是：
在Android應用啟動的時候，去取服務器上版本號 ，與當前應用的對比如果有更新則下載。
下面這個是獲取當前應用的版本信息
private void getCurVersion() {
try {
PackageInfo pInfo = context.getPackageManager().getPackageInfo(
context.getPackageName(), 0);
curVersion = pInfo.versionName;
curVersionCode = pInfo.versionCode;
} catch (NameNotFoundException e) {
Log.e("update", e.getMessage());
curVersion = "1.0.1";
curVersionCode = 1;
}
}
下面則是通過java net包來get版本信息，進行比較
服務器端格式如下 version_1.0.2
HttpURLConnection 獲取輸入流，再用
BufferedReader 緩沖流，readline成String，再比較
private boolean check_update(){
String getstring = null;
String version=null;
getCurVersion();
try {
URL myurl=new URL(app_check);
HttpURLConnection urlconnection=(HttpURLConnection) myurl.openConnection();
urlconnection.setReadTimeout(50000);
urlconnection.setConnectTimeout(50000);
urlconnection.connect();
InputStream in=urlconnection.getInputStream();
BufferedReader buffread;
buffread=new BufferedReader(new InputStreamReader(in,"utf-8"));
String line;
line=buffread.readLine();
while(line!=null){
getstring+=line;
line=buffread.readLine();
}
int index=getstring.indexOf("version_");
//2.0.1
version=getstring.substring(index+8, index+13);
in.close();
Log.e("version",version);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if(version!=null){
if(version.compareTo(curVersion)>0)
return true;
else
return false;
}
else
return false;
}
接下來則是彈出一對話框以及調用下載線程
private void showdownDialog(){
AlertDialog.Builder dialog = new AlertDialog.Builder(context);
dialog.setTitle("軟件版本更新");
dialog.setMessage("有最新的app更新");
dialog.setNegativeButton("以後再說", new OnClickListener(){
@Override
public void onClick(DialogInterface arg0, int arg1) {
// TODO Auto-generated method stub
arg0.dismiss();
}
});
dialog.setPositiveButton("確定", new OnClickListener(){
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
//確定裡面調用下載線程，同時顯示下載的那個進度對話框
dialog.dismiss();
cancel=true;
downapk();
showDownapk();
}
});
dialog.show();
}
最後則是發出一個Intent廣播
private void setInstall(){
File apkfile = new File(apk_path);
if (!apkfile.exists()) {
return;
}
Intent i = new Intent(Intent.ACTION_VIEW);
i.setDataAndType(Uri.parse("file://" + apkfile.toString()), "application/vnd.android.package-archive");
context.startActivity(i);
}
更多Android相關信息見Android 專題頁面 http://www.linuxidc.com/topicnews.aspx?tid=11