安卓课程十五 Button按钮的焦点变化
监听单击事件，键盘事件，焦点变换事件和触碰事件。import android.os.Bundle;import android.app.Activity;import android.view.KeyEvent;import android.view.Menu;import android.view.MotionEvent;import android.view.View;import android.view.View.OnClickListener;import android.view.View.OnFocusChangeListener;import android.view.View.OnKeyListener;import android.view.View.OnTouchListener;import android.widget.Button;public class MainActivity extends Activity implements OnClickListener,OnFocusChangeListener,OnKeyListener,OnTouchListener{private Button btn1;private Button btn2;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);btn1 = (Button) findViewById(R.id.btn1);btn2 = (Button) findViewById(R.id.btn2);btn1.setOnClickListener(this);btn1.setOnFocusChangeListener(this);btn1.setOnKeyListener(this) ;btn2.setOnClickListener(this);btn2.setOnFocusChangeListener(this);btn2.setOnKeyListener(this) ;}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic boolean onKey(View v, int keyCode, KeyEvent event) {if(KeyEvent.ACTION_DOWN == event.getAction()){System.out.println("键盘按下了");}return false;}@Overridepublic void onFocusChange(View v, boolean hasFocus) {// TODO Auto-generated method stubButton btn = (Button)v;if(hasFocus){btn.setBackgroundColor(RESULT_OK);}else {btn.setBackgroundColor(BIND_ABOVE_CLIENT);}}@Overridepublic void onClick(View v) { Button btn = (Button)v; int width = btn.getWidth();// int windowWidth = getWindowManager().getDefaultDisplay().getSize(null); System.out.println(width);}@Overridepublic boolean onTouch(View v, MotionEvent event) { if(MotionEvent.ACTION_UP == event.getAction()){}return false;}}监听单击事件，键盘事件，焦点变换事件和触碰事件。