最近在研究Android动态加载APK技术，偶有小得，共享一下，欢迎交流。
首先是Android 动态加载已安装的APK
被调用工程TestB：
其工程已添加了字符串、颜色和图片资源，这里不写了，读者可自行添加。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | public class TestBActivity extends Activity{ /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button button=(Button)findViewById(R.id.button1); button.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub Toast.makeText(TestBActivity.this, "this is testB", Toast.LENGTH_SHORT).show(); } }); } } |
接着把TestB打包为TestB.apk，放到sdcard的根目录。
调用工程TestA：
首先应该是安装apk文件：
1 2 3 4 5 6 7 8 9 10 | protected void InstallAPK(String apkname) { // TODO Auto-generated method stub //代码安装 String fileName = Environment.getExternalStorageDirectory() + "/"+apkname; Intent intent = new Intent(Intent.ACTION_VIEW); intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); // intent.setDataAndType(Uri.parse("file://"+fileName), "application/vnd.android.package-archive"); intent.setDataAndType(Uri.fromFile(new File(fileName)), "application/vnd.android.package-archive"); TestAActivity.this.startActivityForResult(intent, 1); |
但是安装之前是不是要先检测一下TestB.apk是否已安装呢：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | protected boolean checkInstall(String pak) { // TODO Auto-generated method stub boolean install=false; PackageManager pm=getPackageManager(); try { PackageInfo info=pm.getPackageInfo(pak,1); if (info!=null&&info.activities.length>0) { install=true; } } catch (NameNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } return install; } |
如果未安装，便调用InstallAPK（String apkname）安装，如果已安装便可代码获取其资源：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | private void getRes(String pak){ if (checkInstall(pak)) { try { Context ctxTestB = getTestContext(pak); Resources res = ctxTestB.getResources(); // 获取字符串string String hello = res.getString(getId("string", "hello", pak)); ((TextView) findViewById(R.id.testb_string)).setText(hello); // 获取图片Drawable Drawable drawable = res.getDrawable(getId("drawable", "testb",pak)); ((ImageView) findViewById(R.id.testb_drawable)).setImageDrawable(drawable); // 获取颜色值 int color = res.getColor(getId("color", "white",pak)); ((TextView) findViewById(R.id.testb_color)).setBackgroundColor(color); // 获取布局文件 View view = getView(ctxTestB, getId("layout", "main",pak)); LinearLayout layout = (LinearLayout) findViewById(R.id.testb_layout); layout.addView(view); } catch (NameNotFoundException e) { e.printStackTrace(); }} } //获取资源对应的编号 private int getId(String name, String type,String pak) { return testb.getIdentifier(name, type, pak); } // 获取视图 public View getView(Context ctx, int id) { return ((LayoutInflater) ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(id,null); } //获取TestB的Context private Context getTestContext(String pak) throws NameNotFoundException { return createPackageContext(pak,Context.CONTEXT_IGNORE_SECURITY | Context.CONTEXT_INCLUDE_CODE); } |
接下来再来看看怎么使用Intent组件启动被调用工程：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | protected void startAPK(String pak) { // TODO Auto-generated method stub //代码启动 try { //pak=PACKAGE_TEST_B+".TestBActivity" Context ctxTestB = getTestContext(PACKAGE_TEST_B); Class cls = ctxTestB.getClassLoader().loadClass(pak); TestAActivity.this.startActivity(new Intent(ctxTestB, cls)); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (NameNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } |
以下为扩展内容：
比如加上网络下载apk文件功能，然后再安装，这里使用的是URL通信协议，用HttpURLConnection类，面向的是应用层：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 | protected File downLoadFile(String httpUrl) { // TODO Auto-generated method stub String filename="down_TestB.apk"; File file=new File(Environment.getExternalStorageDirectory() + "/"+filename); try { URL url = new URL(httpUrl); try { HttpURLConnection conn = (HttpURLConnection) url .openConnection(); InputStream is = conn.getInputStream(); FileOutputStream fos = new FileOutputStream(file); byte[] buf = new byte[256]; conn.connect(); int count = 0; if (conn.getResponseCode()==200) { while ((count=is.read(buf))>0) { fos.write(buf, 0, count); } } conn.disconnect(); fos.close(); is.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } catch (MalformedURLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return file; } |
