Android旋轉動畫

我正在研究一個簡單的指南針應用程序。我正在使用旋轉動畫來旋轉圖像，但是當我從0旋轉360度時，圖像翻轉回來以0度開始。如何阻止圖像向後旋轉至0度。Android旋轉動畫

float[] mGravity; 
float[] mGeomagnetic; 
public void onSensorChanged(SensorEvent event) { 
    if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) 
     mGravity = lowPass(event.values, mGravity); 
    if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) 
     mGeomagnetic = lowPass(event.values, mGeomagnetic); 
    if (mGravity != null && mGeomagnetic != null) { 
     float R[] = new float[9]; 
     float I[] = new float[9]; 
     boolean success = SensorManager.getRotationMatrix(R, I, mGravity, mGeomagnetic); 
     if (success) { 
      float orientation[] = new float[3]; 
      SensorManager.getOrientation(R, orientation); 

      //Convert azimuth to degrees 
      float azimuthInDegrees = (float) (Math.toDegrees(orientation[0])+360)%360; 


      //Show coord name 
      String coordNames[] = {"N","NNE", "NE","ENE","E", "ESE","SE","SSE", "S","SSW", "SW","WSW", "W","WNW", "NW","NNW", "N"}; 
      double directionid = Math.round(azimuthInDegrees/22.5); 
      // no of array contain 360/16=22.5 
      if (directionid < 0) { 
       directionid = directionid + 16; 
       //no. of contains in array 
      } 
      String compasLoc = coordNames[(int) directionid]; 

      tvHeading.setText("Heading: " + Float.toString(Math.round(azimuthInDegrees)) + " " + compasLoc); 

      // create a rotation animation (reverse turn degree degrees) 
      RotateAnimation ra = new RotateAnimation(
        currentDegree, 
        -azimuthInDegrees, 
        Animation.RELATIVE_TO_SELF, 0.5f, 
        Animation.RELATIVE_TO_SELF, 
        0.5f); 

      // how long the animation will take place 
      ra.setDuration(210); 
      // set the animation after the end of the reservation status 
      ra.setFillAfter(true); 
      // Start the animation 
      image.startAnimation(ra); 
      currentDegree = -azimuthInDegrees; 
     } 
    } 
}

來源

2015-04-23 brian henry

你能告訴我們你的源代碼嗎？ –

您的意思是說，在360°旋轉之後，它在相反的方向上旋轉回到起始位置？ – rmtheis

是的，它正確地旋轉回到它的起始位置360 –

我用一個靜態toDegrees值

RotateAnimation ra = new RotateAnimation(
    15, 
    -30, // a static vaule 
    Animation.RELATIVE_TO_SELF, 
    0.5f, 
    Animation.RELATIVE_TO_SELF, 
    0.5f);

和圖像旋轉到合適的程度測試你的動畫代碼，該代碼段工作正常。您應該添加日誌以調試startAnimation的調用方式。也許onSensorChanged(SensorEvent event)被再次調用並導致圖像向後旋轉。

來源

2015-04-23 05:37:20 li2

謝謝，我會嘗試。 –

Android旋轉動畫

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