android led应用程序开发.doc

1阅读下面中间件向上Java接口层，完整程序。package com.friendlyarm.AndroidSDK;import android.util.Log;public class LEDControlerstatic public native int openLED();static public native int turnOn();static public native int turnOff();static public native int closeLED(); static try System.（ B ）(friendlyarm-LEDControler); catch (UnsatisfiedLinkError e) Log.d(LEDControler, libfriendlyarm-LEDControler library not found!); AloadBloadLibrary2阅读下面Android应用程序，完整应用程序。package com.friendlyarm.LEDDemo;public class LEDTestingActivity extends Activity （填空1）（implements） OnClickListener private Button btnLED1On; private Button btnLED1Off;private Button btnQuit; Overridepublic void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.main); if( 0=LEDControler.openLED() showDialog(2); else showDialog(3); btnLED1On = (Button)（填空2）（findViewById）(R.id.btnLED1On); btnLED1On.setOnClickListener(this); Override protected Dialog onCreateDialog(int id) AlertDialog.Builder builder = new AlertDialog.Builder(this); if( id = 2 ) builder.setMessage(LED设备打开成功); else if( id = 3 ) builder.setMessage(LED设备打开失败); builder.setPositiveButton(ok, new DialogInterface.OnClickListener() public void onClick(DialogInterface dialog, int which) ); return builder.create(); public void onClick(View v) switch (v.（填空3）（getId）() case R.id.btnLED1On:LEDControler.turnOn();break;case R.id.btnLED1Off:LEDControler.turnOff();break;case R.id.btnQuit:LEDControler.closeLED();this.finish();break;default:break;3（ A ）是Android组件中最基本也是最为常用的组件，在一个android应用中，通常就是一个单独的屏幕。AActivityBView4用Eclipse开发Android应用程序，界面层实现绝对布局的元素是（ D ）。A LinearLayoutB RelativeLayoutC. FrameLayoutD. AbsoluteLayo