在安卓开发的过程中有时候我们需要调用第三方APK应用的时候，并不知道其中的包名和类名，可以调用下面的方法获取所需要的包名和类名。

  /** 
 * 
 * 通过APK地址获取此APP的包名和版本等信息 
 * */
private void getPackageName() {
        String FilePath="*.apk";//输入APK地址
        PackageManager pm = getPackageManager();    
        PackageInfo info = pm.getPackageArchiveInfo(FilePath, PackageManager.GET_ACTIVITIES);    
        if(info != null){    
            ApplicationInfo appInfo = info.applicationInfo;    
            String appName = pm.getApplicationLabel(appInfo).toString();    
            String packageName = appInfo.packageName;  //获取安装包名称 
            Log.i("Abel_Test", "包名是："+packageName);
            String version=info.versionName; //获取版本信息 
Log.i("Abel_Tes", "版本信息："+version);

   }
        }

 /** 
 * 
 * 通过包名获取此APP详细信息，包括Activities、services、versioncode、name等等 并且可以直接调用
 * */
private void doStartApplicationWithPackageName(String packagename) {


PackageInfo packageinfo = null;
try {
packageinfo = getPackageManager().getPackageInfo(packagename, 0);
} catch (NameNotFoundException e) {
e.printStackTrace();
}
if (packageinfo == null) {
return;
}


// 创建一个类别为CATEGORY_LAUNCHER的该包名的Intent
Intent resolveIntent = new Intent(Intent.ACTION_MAIN, null);
resolveIntent.addCategory(Intent.CATEGORY_LAUNCHER);
resolveIntent.setPackage(packageinfo.packageName);


// 通过getPackageManager()的queryIntentActivities方法遍历
List<ResolveInfo> resolveinfoList = getPackageManager()
.queryIntentActivities(resolveIntent, 0);


ResolveInfo resolveinfo = resolveinfoList.iterator().next();
if (resolveinfo != null) {
// packagename = 参数packname
String packageName = resolveinfo.activityInfo.packageName;
// 这个就是我们要找的该APP的LAUNCHER的Activity[组织形式：packagename.mainActivityname]
String className = resolveinfo.activityInfo.name;
Log.i("Abel_Test", "类名是："+className);
// LAUNCHER Intent
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);


// 设置ComponentName参数1:packagename参数2:MainActivity路径
ComponentName cn = new ComponentName(packageName, className);
       
intent.setComponent(cn);
startActivity(intent);
}
}