源码：

1         FragmentTransaction mFragmentTranscation = getSupportFragmentManager().beginTransaction();2         Fragment mMainFragment = new MainFragment();//此行提示出错3         mFragmentTranscation.replace(R.id.container, mMainFragment);4         mFragmentTranscation.commit();

 

错误提示：无法将MainFragment (Fragment的子类)强制转换成Fragment

解决方法：

在原来的MainFragment中把

import android.app.Fragment;

更改为:

import android.support.v4.app.Fragment;