android按钮点击响应——xml方式

还可以在XML中定义点击事件，然后在activity中事件这个方法，注意这个方法必须是public void (View v){}这种形式，否则不能进行响应。

下面是代码：

package xueyou.xueyoucto.com.androidviews;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.MotionEvent;import android.view.View;import android.widget.Button;import android.widget.Toast;public class MainActivity extends AppCompatActivity{    private final String Tag = "MAINACTIVITY";    public Button button1;    public Button button2;    public Button button3;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        button1 = (Button) this.findViewById(R.id.button1);        button2 = (Button) this.findViewById(R.id.button2);        button3 = (Button) this.findViewById(R.id.button3);    }    public  void button1Click(View v){        Toast.makeText(MainActivity.this, "button1 clicked!", Toast.LENGTH_SHORT).show();    }    public void button2Click(View v){        Toast.makeText(MainActivity.this, "button2 clicked!", Toast.LENGTH_SHORT).show();    }    public void button3Click(View v){        Toast.makeText(MainActivity.this, "button3 clicked!", Toast.LENGTH_SHORT).show();    }}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/mainRelativeLayout"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="xueyou.xueyoucto.com.androidviews.MainActivity">    <Button        android:id="@+id/button1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentStart="true"        android:layout_alignParentTop="true"        android:layout_marginLeft="35dp"        android:layout_marginStart="35dp"        android:layout_marginTop="49dp"        android:onClick="button1Click"        android:text="Button1" />    <Button        android:id="@+id/button2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignLeft="@+id/button1"        android:layout_alignStart="@+id/button1"        android:layout_below="@+id/button1"        android:layout_marginTop="112dp"        android:onClick="button2Click"        android:text="button2" />    <Button        android:id="@+id/button3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignLeft="@+id/button2"        android:layout_alignParentBottom="true"        android:layout_alignStart="@+id/button2"        android:layout_marginBottom="103dp"        android:onClick="button3Click"        android:text="button3" /></RelativeLayout>

运行结果：