版本更新

<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"></uses-permission>

hu = new HttpUtils();
tv = (TextView) findViewById(R.id.tv);
//得到版本号
try {
int versionCode = getPackageManager().getPackageInfo("com.example.lenovo.version", 0).versionCode;
} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
}
String path="";

//path是获取版本号的地址
hu.send(HttpRequest.HttpMethod.GET, "path",
new RequestCallBack<String>() {
//重写成功方法
@Override
public void onSuccess(ResponseInfo<String> responseInfo) {

System.out.println("连接成功！");
//服务器返回的json串
String result = responseInfo.result;
//
//                        if (versionCode < 服务器获得的版本号) {
//                                //下载方法
xiazai(hu);
//                        }

}

//重写时报方法
@Override
public void onFailure(HttpException e, String s) {
System.out.println("连接成功！");
}
}
);

private void xiazai(HttpUtils hu) {
// 文件的下载
File file = new File(Environment.getExternalStorageDirectory(), "baiduxinwen.apk");
hu.download("http://gdown.baidu.com/data/wisegame/f98d235e39e29031/baiduxinwen.apk", file.getAbsolutePath(), true, true, new RequestCallBack<File>() {

@Override
public void onSuccess(ResponseInfo<File> responseInfo) {

Toast.makeText(MainActivity.this, "下载成功！", Toast.LENGTH_SHORT).show();
//按装方法
anzhuang();
}

@Override
public void onFailure(HttpException e, String s) {
//Log.i("zzz","失败");
Log.i("zzz", "失败" + e.getMessage() + "   ------------------" + s.toString());

}

@Override
public void onStart() {
Log.i("zzz", "开始");

}

@Override
public void onLoading(long total, long current, boolean isUploading) {
tv.setText(current + "/" + total);
//下载进度
Log.i("zzz", current + ":" + total);
Toast.makeText(MainActivity.this, "正在下载", Toast.LENGTH_SHORT).show();
}

});
}

private void anzhuang() {

String fileName = "/sdcard";
Intent i = new Intent();
i.setAction(Intent.ACTION_VIEW);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
i.setDataAndType(Uri.fromFile(new File(fileName)), "application/vnd.android.package-archive");
startActivity(i);
Toast.makeText(MainActivity.this, "安装成功！", Toast.LENGTH_SHORT).show();
}