android的按键事件

来源：互联网发布：重庆加工贸易数据编辑：程序博客网时间：2024/04/27 16:39

本文转自http://blog.sina.com.cn/s/blog_6714fba70100wkib.html

事件使我们在于UI交互式发生的，我们点击一个按键时，可能就已经除非好几个事件，例如我们点击数字键“0”，他会涉及到按下事件，和一个弹起（松开）事件，在我们android中还可能涉及到触摸屏事件，所以在android系统中，事件是作为常用的功能之一；

onClick(View v)一个普通的点击按钮事件

boolean onKeyMultiple(int keyCode,int repeatCount,KeyEvent event)用于在多个事件连续时发生，用于按键重复，必须重载@Override实现

boolean onKeyDown(int keyCode,KeyEvent event)用于在按键进行按下时发生

boolean onKeyUp(int keyCode,KeyEvent event）用于在按键进行释放时发生

onTouchEvent(MotionEvent event)触摸屏事件，当在触摸屏上有动作时发生

需要知道按的是哪个键和哪个动作

publicvoid DisplayToast(String str)    {     Toast.makeText(this, str, Toast.LENGTH_SHORT).show();    }publicclassKeyEventActivityextendsActivity{privateButtonbutton;@OverridepublicvoidonCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.main);button= (Button) findViewById(R.id.ok_button);button.setOnClickListener(listener);}OnClickListenerlistener=newOnClickListener(){@OverridepublicvoidonClick(View v){DisplayToast("点击了OK！");}};publicbooleanonKeyDown(intkeyCode, KeyEvent event){switch(keyCode){caseKeyEvent.KEYCODE_DPAD_CENTER:DisplayToast("按下：中间键");break;caseKeyEvent.KEYCODE_DPAD_UP:DisplayToast("按下：向上键");break;caseKeyEvent.KEYCODE_DPAD_DOWN:DisplayToast("按下：向下键");break;caseKeyEvent.KEYCODE_DPAD_LEFT:DisplayToast("按下：左方向键");break;caseKeyEvent.KEYCODE_DPAD_RIGHT:DisplayToast("按下：有方向键");break;default:break;}returnsuper.onKeyDown(keyCode, event);}publicbooleanonKeyUp(intkeyCode, KeyEvent event){switch(keyCode){caseKeyEvent.KEYCODE_DPAD_CENTER:DisplayToast("弹起：中间键");break;caseKeyEvent.KEYCODE_DPAD_DOWN:DisplayToast("弹起：向下键");break;caseKeyEvent.KEYCODE_DPAD_LEFT:DisplayToast("弹起：向左键");break;caseKeyEvent.KEYCODE_DPAD_RIGHT:DisplayToast("弹起：向右键");break;caseKeyEvent.KEYCODE_DPAD_UP:DisplayToast("弹起：向上键");break;}returnsuper.onKeyDown(keyCode, event);}publicbooleanonKeyMultiple(intkeyCode,intrepeatCount, KeyEvent event){returnsuper.onKeyMultiple(keyCode, repeatCount, event);}publicbooleanonTouchEvent(MotionEvent event){intiAction = event.getAction();if(iAction == MotionEvent.ACTION_CANCEL|| iAction == MotionEvent.ACTION_DOWN|| iAction == MotionEvent.ACTION_MOVE){returnfalse;}intx = (int) event.getX();inty = (int) event.getY();DisplayToast("触笔点击坐标:("+ Integer.toString(x) +","+ Integer.toString(y) +")");returnsuper.onTouchEvent(event);}publicvoidDisplayToast(String str){Toast.makeText(this, str, Toast.LENGTH_SHORT).show();}}

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