按钮点击跳转（多）

例：

主页面类：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    //封装全局变量（成员变量）
    private Button btn01;
    private Button btn02;
    private Button btn03;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //找控件
        btn01 = findViewById(R.id.btn01);
        btn02 = findViewById(R.id.btn02);
        btn03 = findViewById(R.id.btn03);
        //点击监听事件
        btn01.setOnClickListener(this);
        btn02.setOnClickListener(this);
        btn03.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.btn01:
                Intent intent1 = new Intent(MainActivity.this,Main1Activity.class);
                startActivity(intent1);
                break;
            case R.id.btn02:
                Intent intent2 = new Intent(MainActivity.this,Main2Activity.class);
                startActivity(intent2);
                break;
            case R.id.btn03:
                Intent intent3 = new Intent(MainActivity.this,Main3Activity.class);
                startActivity(intent3);
                break;
        }
    }
}

布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:fresco="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <Button
        android:id="@+id/btn01"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:text="btn01" />
    <Button
        android:id="@+id/btn02"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:text="btn02" />
    <Button
        android:id="@+id/btn03"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:text="btn03" />
</LinearLayout>

点击跳转按钮：

添加权限：
<application>在这个控件中加入参数（需要跳转的页面）   

<activity android:name=".Main1Activity"/>
<activity android:name=".Main2Activity"/>
<activity android:name=".Main3Activity"/>

</ application>

点击跳转的新页面主类：

public class Main2Activity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
    }
}

activity_main2

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Main2Activity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="11111111111111" />

</RelativeLayout>