Android 如何使用按钮切换活动？

如何使用按钮切换活动？这是我的问题：

package net.example.finals;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Button;
import android.os.Build;



public class MainActivity extends ActionBarActivity {

@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();
    }
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

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

    Button bq;
    Button bw;
    Button be;
    Button br;
    Button bt;
    Button by;
    Button bu;


    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_second,
                container, false);

        bq=(Button)rootView.findViewById(R.id.btn1);
        bq.setOnClickListener(this);
        bw=(Button)rootView.findViewById(R.id.btn2);
        bw.setOnClickListener(this);
        be=(Button)rootView.findViewById(R.id.btn3);
        be.setOnClickListener(this);
        br=(Button)rootView.findViewById(R.id.btn4);
        br.setOnClickListener(this);
        bt=(Button)rootView.findViewById(R.id.btn5);
        bt.setOnClickListener(this);
        by=(Button)rootView.findViewById(R.id.btn6);
        by.setOnClickListener(this);
        bu=(Button)rootView.findViewById(R.id.btn7);
        bu.setOnClickListener(this);

        return rootView;
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub


        //i dont know what to put here
    case R.id.btn1:
        if(bq.callOnClick()==true){
        Intent myOwnIntent = new Intent(getActivity(), Second.class);
        startActivity(myOwnIntent);
        }
        break;







        }

    }

}为什么要使用ifbq.callOnClick==true

Android使用大量java代码，首先你需要正确地学习java

还有谷歌

试试这个

---

学习switch case，你就会知道应该在那里放什么：我应该在YourActivityName中放什么？因为当我输入活动名称时，它会变成红色。输入MainActivity。这是您的案例

@Override
public void onClick(View v) {
    int id = v.getId();

    switch(id){
        case R.id.btn1:
        Intent myOwnIntent = new Intent(YourActivityName.this, Second.class);
        startActivity(myOwnIntent);
        break;
    }
}