安卓学习之初试事件响应—

安卓学习之初试事件响应——Button

1.界面布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
   <Button 
   android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
     android:text="Click me!"
     android:id="@+id/btn1"
   />
</LinearLayout>

2.事件响应代码（两种），第二种被我注释了

package cn.edu.bit.cs;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class UseButtonActivity extends Activity {
    private Button btn1=null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btn1=(Button)this.findViewById(R.id.btn1);
        //使用独立的事件响应对象
        btn1.setOnClickListener(new ButtonClick());
        //使用匿名内部类挂接事件响应代码
        /*
         btn1.setOnClickListener(new View.OnClickListener() {
            private int counter=0;
            public void onClick(View v) {
                Button clickedButton=(Button)v;
                counter++;
                //在手机上显示短暂的信息
                Toast info=Toast.makeText(UseButtonActivity.this, "Button "+v.getId()+" has been clicked "+ counter + " times!", Toast.LENGTH_SHORT);
                info.setDuration(1);
                info.show();
            }
        });
         */
    }
}
class ButtonClick implements OnClickListener{
    private int counter=0;
    public void onClick(View v) {
        counter++;
        //在logCat中才能看到输出
        System.out.println("I'm clicked "+ counter + " times!");
    }
}