The specified child already has a parent. You must call removeView() on the child's parent first.

报错：

The specified child already has a parent. You must call removeView() 
on the child's parent first.

我是在用Android第三方库SlideMenu的时候出现的错误 ，原来的代码是把supportFragmentManager得到的manager赋给一个字段，以后就直接调用这个字段。

错误代码

private FragmentManager supportFragmentManager;

supportFragmentManager = getSupportFragmentManager();
        supportFragmentManager.beginTransaction().replace(R.id.content_frame, new ContentFragment()).commit();
        setBehindContentView(R.layout.left_activity);

        supportFragmentManager.beginTransaction().replace(R.id.left_frame, new LeftFragment()).commit();

后来比对sample代码，发现不赋值字段就OK了

getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, new ContentFragment()).commit();

可是再验证再用字段时，发现又OK了。我有点晕了，你们且试试吧！如果仍旧出错，或你有什么好的解决方案就贴给我吧！