如何解决错误＆＃34;无法解决方法＆＃39; add（int，com.web＆＃34;

Question

我收到错误

  

无法解析方法＆＃39;添加   fragmentTransaction.add（R.id.fragment_container中，f1）;

当我试图运行该应用程序时，它说：

  

遗憾的是，您的申请已停止

代码：

import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity{
    Button bn;
    boolean status = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        bn = (Button) findViewById(R.id.bn);
        bn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                FragmentManager fragmentManager =getFragmentManager();
                FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
                if(!status)
                {
                     FragmentOne f1 = new FragmentOne();
                    fragmentTransaction.add(R.id.fragment_container,f1);
                    fragmentTransaction.commit();
                    bn.setText("LOAD SECOND FRAGMENT");
                    status = true;
                }
                else
                {
                  FragmentTwo f2 = new  FragmentTwo();
                    fragmentTransaction.add(R.id.fragment_container,f2);
                    fragmentTransaction.commit();
                    bn.setText("LOAD FIRST FRAGMENT");
                    status = false;

                }

            }
        });
    }
}

Answer 1

＆＃34; MainActivity.java＆＃34;你的片段的java必须

使用相同的 import android.app.Fragment;要么 import android.support.v4.app.Fragment;