The method replace(int, Fragment, String) in the type FragmentTransaction is not applicable for the arguments (int, SettingFragment, String)

The method replace(int, Fragment, String) in the type FragmentTransaction is not applicable for the arguments (int, SettingFragment, String)

引发错误的原因是因为import包的时候Fragment是引用的V4的，而activity继承Activity。
而getFragmentManager()是activity中的方法
但是getSupportFragmentManager是FragmentActivity中的方法
使用要统一

最后

package com.example.fragment;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;

public class MainActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment()).commit();
        }
    }
}

package com.example.fragment;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;

/**
 * A placeholder fragment containing a simple view.
 */
public class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container,
                false);
        rootView.findViewById(R.id.btnshow).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                getFragmentManager().beginTransaction().replace(R.id.container, new AnotherFragment()).commit();
            }
        });
        return rootView;
    }
}