主要原理是：
在应用启动的时候，去取服务器上版本号 ，与当前应用的对比如果有更新则下载
下面这个是获取当前应用的版本信息
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;
}
}
下面则是通过java net包来get版本信息，进行比较
服务器端格式如下 version_1.0.2
HttpURLConnection 获取输入流，再用
BufferedReader 缓冲流，readline成String，再比较
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;
}
接下来则是弹出一对话框以及调用下载线程
private void showdownDialog(){
AlertDialog.Builder dialog = new AlertDialog.Builder(context);
dialog.setTitle("软件版本更新");
dialog.setMessage("有最新的app更新");
dialog.setNegativeButton("以后再说", new OnClickListener(){
@Override
public void onClick(DialogInterface arg0, int arg1) {
// TODO Auto-generated method stub
arg0.dismiss();
}
});
dialog.setPositiveButton("确定", new OnClickListener(){
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
//确定里面调用下载线程，同时显示下载的那个进度对话框
dialog.dismiss();
cancel=true;
downapk();
showDownapk();
}
});
dialog.show();
}
最后则是发出一个Intent广播
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);
}