android 簡易儀表盤的設計

     最近需要做一個可以定時獲取數據並刷新數據在儀表盤上顯示的功能，可以實現順時針和逆時針的擺動，將完成的一個Demo記錄下來供參考學習，有不足之處還望路過者指點……

     主要設置代碼如下：

public class MainActivity extends Activity {
 private ImageView needleView; // 指針圖片
 private Timer timer; // 時間
 private EditText degreeText;
 private TextView showText;
 private Button degreeBtn;
 private float maxDegree = 0.0f;
 private float degree = 0.0f; // 記錄指針旋轉
 private RotateAnimation animation;
 private boolean flag = true;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);

  needleView = (ImageView) findViewById(R.id.needle);
  degreeText = (EditText) findViewById(R.id.degreeID2);
  degreeBtn = (Button) findViewById(R.id.degreeButton);
  showText=(TextView)findViewById(R.id.degreeID);
  degreeBtn.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    maxDegree = Float.parseFloat(degreeText.getText().toString()
      .trim());
    // 開始轉動
    timer = new Timer();
    // 設置每10毫秒轉動一下
    timer.schedule(new NeedleTask(), 0, 10);
    showText.setText(degreeText.getText().toString()
      .trim());
    flag = true;
   }
  });
 }

 private class NeedleTask extends TimerTask {
  @Override
  public void run() {
   if (degree <= maxDegree * (271 / 100.0f)) {
    handler.sendEmptyMessage(0);
   }
   if (degree > maxDegree * (271 / 100.0f) && flag == true) {
    handler2.sendEmptyMessage(0);
   }
  }
 }

//輸入數值比初始值大時

 private Handler handler = new Handler() {
  @Override
  public void handleMessage(Message msg) {
   // 設置儀表盤指針轉動動畫
   // 儀表盤最大是271度
   if (degree >= maxDegree * (271 / 100.0f)) {
    timer.cancel();
   }else{
   degree += 5.0f;
   animation = new RotateAnimation(degree, maxDegree * (271 / 100.0f),
     Animation.RELATIVE_TO_SELF, 0.5f,
     Animation.RELATIVE_TO_SELF, 0.5f);
   }
   // 設置動畫時間1秒
   animation.setDuration(10);
   animation.setFillAfter(true);
   needleView.startAnimation(animation);
   flag = false;
  }
 };

//當輸入數值比前一次小時

 private Handler handler2 = new Handler() {
  @Override
  public void handleMessage(Message msg) { // 設置儀表盤指針轉動動畫
   // 儀表盤最大是271度，這個是自己測出來的
   if (degree <= maxDegree * (271 / 100.0f)) {
    timer.cancel();
   }else{
   degree += -5.0f;
   animation = new RotateAnimation(degree, maxDegree * (271 / 100.0f),
     Animation.RELATIVE_TO_SELF, 0.5f,
     Animation.RELATIVE_TO_SELF, 0.5f);
   }
   // 設置動畫時間5毫秒
   animation.setDuration(10);
   animation.setFillAfter(true);
   needleView.startAnimation(animation);
   flag = true;
  }
 };

 /**
  * 關閉計時器對象
  */
 @Override
 protected void onDestroy() {
  timer.cancel();
  timer = null;
  super.onDestroy();
 }
}

效果圖如下

源碼下載地址：http://download.csdn.net/detail/flyer5/6575753