1.簡單實現

直接上程式碼

package com.dyb.testcamerademo;

import android.app.DownloadManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import
 
 android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.support.v4.content.FileProvider;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;

import
 
 java.io.File;

public class Main2Activity extends AppCompatActivity {
    private Context mContext;
    private DownloadManager mDownloadManager;
    private long downloadId;
    private boolean isForceUpdate = true;//是否強制升級

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super
 
.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        mContext = this;
        initVersionUpdate();
    }

    private void initVersionUpdate() {
        checkUpdate();
    }

    /**
     * 檢測軟體更新
     */
    public void checkUpdate() {
        if (isUpdate()) {
            // 顯示提示對話方塊
            showNoticeDialog();
        } else {
            Toast.makeText(mContext, "沒有新版", Toast.LENGTH_LONG).show();
        }
    }

    /**
     * 顯示軟體更新對話方塊
     */
    private void showNoticeDialog() {
        // 更新
        AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);

        dialog.setTitle("軟體更新")
                .setMessage("檢測到新版本，立即更新嗎")
                .setPositiveButton("更新", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                        Toast.makeText(mContext, "正在通知欄下載中", Toast.LENGTH_SHORT).show();

                        // 顯示下載對話方塊
                        showDownloadDialog();
                    }
                });
        if (!isForceUpdate) {
            dialog.setNegativeButton("下次再說", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                }
            });

        }
        dialog.setCancelable(false);
        dialog.show();
    }

    /**
     * 顯示軟體下載對話方塊
     */
    private void showDownloadDialog() {
        //安裝包路徑 此處模擬為百度新聞APP地址
        String downPath = "http://gdown.baidu.com/data/wisegame/f98d235e39e29031/baiduxinwen.apk";

        //使用系統下載類
        mDownloadManager = (DownloadManager) mContext.getSystemService(DOWNLOAD_SERVICE);
        Uri uri = Uri.parse(downPath);
        DownloadManager.Request request = new DownloadManager.Request(uri);
        request.setAllowedOverRoaming(false);

        //建立目錄下載
        request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "百度.apk");
        // 把id儲存好，在接收者裡面要用
        downloadId = mDownloadManager.enqueue(request);
        //設定允許使用的網路型別，這裡是行動網路和wifi都可以
        request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_MOBILE | DownloadManager.Request.NETWORK_WIFI);
        //機型適配
        request.setMimeType("application/vnd.android.package-archive");
        //通知欄顯示
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
        request.setTitle("測試APP");
        request.setDescription("正在下載中...");
        request.setVisibleInDownloadsUi(true);
        mContext.registerReceiver(mReceiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
    }

    /**
     * 判斷是否有更新，需要跟後臺產生資訊互動
     *
     * @return
     */
    private boolean isUpdate() {
        // 獲取當前軟體版本
        int versionCode = getVersionCode(mContext);

        // 呼叫方法獲取伺服器可用版本資訊，此處模擬為大於當前版本的定值
        int serviceCode = 2;

        // 版本判斷
        if (serviceCode > versionCode) {
            return true;
        }
        return false;
    }

    /**
     * 獲取本地軟體版本號
     *
     * @param context
     * @return
     */
    private int getVersionCode(Context context) {
        int versionCode = 0;
        try {
            // 獲取軟體版本號，對應AndroidManifest.xml下android:versionCode
            versionCode = context.getPackageManager().getPackageInfo(context.getPackageName(), 0).versionCode;
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return versionCode;
    }

    private BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            checkStatus();
        }
    };

    /**
     * 檢查下載狀態
     */
    private void checkStatus() {
        DownloadManager.Query query = new DownloadManager.Query();
        query.setFilterById(downloadId);
        Cursor cursor = mDownloadManager.query(query);
        if (cursor.moveToFirst()) {
            int status = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));
            switch (status) {
                //下載暫停
                case DownloadManager.STATUS_PAUSED:
                    break;
                //下載延遲
                case DownloadManager.STATUS_PENDING:
                    break;
                //正在下載
                case DownloadManager.STATUS_RUNNING:
                    break;
                //下載完成
                case DownloadManager.STATUS_SUCCESSFUL:
                    installAPK();
                    break;
                //下載失敗
                case DownloadManager.STATUS_FAILED:
                    Toast.makeText(mContext, "下載失敗", Toast.LENGTH_SHORT).show();
                    break;
            }
        }
        cursor.close();
    }

    /**
     * 7.0相容
     */
    private void installAPK() {
        File apkFile =
                new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), "百度.apk");
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            Uri apkUri = FileProvider.getUriForFile(mContext, mContext.getPackageName() + ".fileprovider", apkFile);
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            intent.setDataAndType(apkUri, "application/vnd.android.package-archive");
        } else {
            intent.setDataAndType(Uri.fromFile(apkFile), "application/vnd.android.package-archive");
        }
        mContext.startActivity(intent);
    }
}

配置檔案AndroidManifest.xml程式碼：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.dyb.testcamerademo">

    <!-- sd卡寫許可權 -->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <!-- 網路 -->
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".Main2Activity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>

        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="com.dyb.testcamerademo.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/file_paths"/>
        </provider>

        <activity android:name=".MainActivity">
        </activity>
    </application>

</manifest>

res包下新建xml包，新建的file_paths.xml程式碼如下：

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">

<!--
name屬性的值可以隨便寫,別名
path屬性的值表示共享的具體位置，設定空就表示將整個SD卡進行共享
 -->
<paths>
    <external-path
        name="camera_photos"
        path=""/>
</paths>
</paths>