有时，需要在应用程序中调用其他Android上已经安装完好的应用程序，
以下是一个调用相机(com.android.camera)的demo程序:PackageInfo pi = null; try { //获得相机包名信息 pi = getPackageManager().getPackageInfo("com.android.camera", 0);} catch (NameNotFoundException e) { e.printStackTrace();}//获得当前应用程序的包管理器PackageManager pm = MainActivity.this.getPackageManager(); Intent resolveIntent = new Intent(Intent.ACTION_MAIN, null); resolveIntent.addCategory(Intent.CATEGORY_LAUNCHER);resolveIntent.setPackage(pi.packageName);List apps = pm.queryIntentActivities(resolveIntent, 0);ResolveInfo ri = apps.iterator().next();if (ri != null ) {String packageName = ri.activityInfo.packageName;String className = ri.activityInfo.name;Intent intent = new Intent(Intent.ACTION_MAIN);intent.addCategory(Intent.CATEGORY_LAUNCHER);ComponentName cn = new ComponentName(packageName, className);intent.setComponent(cn);startActivity(intent); }