模拟版本更新

package com.bb.banben;import android.app.ProgressDialog;import android.content.DialogInterface;import android.content.Intent;import android.content.pm.PackageInfo;import android.content.pm.PackageManager;import android.net.Uri;import android.os.Environment;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import com.bwie.banben.bean.Config;import com.bwie.banben.bean.Version;import org.xutils.common.Callback;import org.xutils.http.RequestParams;import org.xutils.x;import java.io.File;public class MainActivity extends AppCompatActivity {    private String url = "http://125.39.134.47/r/a.gdown.baidu.com/data/wisegame/7c28ac069399b336/kuaishou_4812.apk";    private ProgressDialog progressDialog;//加载框    private Callback.Cancelable cancelable;//请求任务对象    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initDialog();    }    private void initDialog() {        progressDialog = new ProgressDialog(this);        progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);        progressDialog.setButton(ProgressDialog.BUTTON_NEGATIVE, "暂停", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialogInterface, int i) {                //取消下载任务                cancelable.cancel();            }        });    }    public void check(View view) throws PackageManager.NameNotFoundException {        PackageManager manager = getPackageManager();        PackageInfo info = manager.getPackageInfo(getPackageName(), 0);        int versionCode = info.versionCode;        Version version = new Version();//自己创建的一个对象，里面封装了版本号和下载地址        version.setUrl(url);        if (versionCode < version.getVersionCode()) {           // File file = new File(Config.VERSION_PATH);            //System.out.println("file = " + file.getAbsolutePath());            downloadApk();        }    }    private void downloadApk() {        final RequestParams request = new RequestParams(url);        request.setAutoResume(true);//设置是否支持断点下载        request.setCancelFast(true);//设置是否立即取消        //判断sdcard是否可用        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {//判断sdcard存在并且可用            request.setSaveFilePath(Config.VERSION_PATH);//自己创建的一个类，里面存放了下载路径public static final String VERSION_PATH = Environment.getExternalStorageDirectory()+"/danney/versions.apk";        }        cancelable = x.http().get(request, new Callback.ProgressCallback<File>() {            @Override            public void onSuccess(File result) {                progressDialog.dismiss();                System.out.println("filepath====" + result.getAbsolutePath());                install(result);            }            @Override            public void onError(Throwable ex, boolean isOnCallback) {            }            @Override            public void onCancelled(CancelledException cex) {            }            @Override            public void onFinished() {            }            @Override            public void onWaiting() {            }            @Override            public void onStarted() {                progressDialog.show();            }            @Override            public void onLoading(long total, long current, boolean isDownloading) {                if (isDownloading) {                    progressDialog.setMax((int) total);                    progressDialog.setProgress((int) current);                    progressDialog.setTitle("下载进度");                    System.out.println("current:" + (int) current * 100 / total);                }            }        });    }    private void install(File file) {        //调用系统安装器        Intent intent = new Intent(Intent.ACTION_VIEW);        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);        intent.setDataAndType(Uri.parse("file://" + file.getAbsolutePath()), "application/vnd.android.package-archive");        startActivity(intent);    }}注意加网络权限和可写权限