Question

我需要做的是在圆圈外边缘绘制的位图我有时会把它弄好，但是当我旋转设备时它会出错我也尝试了旋转动画，但我没有得到我想要的结果。

请帮忙。

这是预期的：

我得到的是：对于这张图片，它运作良好

它在这里出错了

在这里：

代码（指南针的谷歌教程）：

CompassFragment类：

   public class CompassFragment extends Fragment implements SensorEventListener {

    SensorManager sensorManager;
    private Sensor sensorAccelerometer;
    private Sensor sensorMagneticField;

    private float[] valuesAccelerometer;
    private float[] valuesMagneticField;

    private float[] matrixR;
    private float[] matrixI;
    private float[] matrixValues;

    TextView readingAzimuth, readingPitch, readingRoll;
    Compass myCompass;
 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_compass, container, false);
        readingAzimuth = (TextView) view.findViewById(R.id.azimuth);
        readingPitch = (TextView) view.findViewById(R.id.pitch);
        readingRoll = (TextView) view.findViewById(R.id.roll);
        myCompass = (Compass) view.findViewById(R.id.mycompass);
        return view;
    }

  @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        sensorManager = (SensorManager) getActivity().getSystemService(Context.SENSOR_SERVICE);
        sensorAccelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        sensorMagneticField = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);

        valuesAccelerometer = new float[3];
        valuesMagneticField = new float[3];

        matrixR = new float[9];
        matrixI = new float[9];
        matrixValues = new float[3];

    }

@Override
    public void onResume() {

        sensorManager.registerListener(this,
                sensorAccelerometer,
                SensorManager.SENSOR_DELAY_NORMAL);
        sensorManager.registerListener(this,
                sensorMagneticField,
                SensorManager.SENSOR_DELAY_NORMAL);
        super.onResume();
    }

@Override
    public void onPause() {

        sensorManager.unregisterListener(this,
                sensorAccelerometer);
        sensorManager.unregisterListener(this,
                sensorMagneticField);
        super.onPause();
    }

@Override
    public void onSensorChanged(SensorEvent event) {
        switch (event.sensor.getType()) {
            case Sensor.TYPE_ACCELEROMETER:
                for (int i = 0; i < 3; i++) {
                    valuesAccelerometer[i] = event.values[i];
                }
                break;
            case Sensor.TYPE_MAGNETIC_FIELD:
                for (int i = 0; i < 3; i++) {
                    valuesMagneticField[i] = event.values[i];
                }
                break;
        }

        boolean success = SensorManager.getRotationMatrix(
                matrixR,
                matrixI,
                valuesAccelerometer,
                valuesMagneticField);

        if (success) {
            SensorManager.getOrientation(matrixR, matrixValues);

            double azimuth = Math.toDegrees(matrixValues[0]);
            double pitch = Math.toDegrees(matrixValues[1]);
            double roll = Math.toDegrees(matrixValues[2]);

            readingAzimuth.setText("Azimuth: " + String.valueOf(azimuth));
            readingPitch.setText("Pitch: " + String.valueOf(pitch));
            readingRoll.setText("Roll: " + String.valueOf(roll));

            myCompass.update(matrixValues[0]);
        }

    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }
}

指南针课程：

public class Compass extends View {
    private Bitmap bitmap;
    private float direction;
    private HashMap<String, Bitmap> mStore = new HashMap<String, Bitmap>();
    private Context context;
    private int h, w, r;
    private Paint paint;
    private Canvas canvas;

    public Compass(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
        this.context = context;

    }

    public Compass(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
    }

    public Compass(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // TODO Auto-ge

    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        setMeasuredDimension(
                MeasureSpec.getSize(widthMeasureSpec),
                MeasureSpec.getSize(heightMeasureSpec));
    }
 @Override
    protected void onDraw(Canvas canvas) {
        w = getMeasuredWidth();
        h = getMeasuredHeight();
        r = 0;
        if (w > h) {
            r = h / 2;
        } else {
            r = w / 2;
        }
        paint = new Paint();
//        Paint.ANTI_ALIAS_FLAG
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(5);
        paint.setColor(Color.WHITE);
        paint.setAntiAlias(true);
        canvas.drawCircle(w / 2, h / 2, r, paint);
        paint.setColor(Color.RED);
        drawImage1(canvas);
    }
    private void drawImage1(Canvas canvas) {
        BitmapFactory.Options myOptions = new BitmapFactory.Options();
        myOptions.inDither = true;
        myOptions.inScaled = false;
        myOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;// important
        myOptions.inPurgeable = true;
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher, myOptions);
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setColor(Color.BLUE);
        Bitmap workingBitmap = Bitmap.createBitmap(bitmap);
        Bitmap mutableBitmap = workingBitmap.copy(Bitmap.Config.ARGB_8888, true);
        float left = (float) ((w / 2 + r * Math.sin(-direction)));
        float top = (float) (h / 2 - r * Math.cos(-direction));
        Log.e("cords", left + "  " + top);
        canvas.drawBitmap(mutableBitmap, left, top, paint);
    }
}


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">


        <TextView
            android:id="@+id/azimuth"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColor="@color/mainColor" />

        <TextView
            android:id="@+id/pitch"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColor="@color/mainColor" />

        <TextView
            android:id="@+id/roll"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColor="@color/mainColor" />
    </LinearLayout>

    <com.example.compass.Compass
        android:id="@+id/mycompass"
        class="com.nilecode.Compass"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp">

    </com.example.compass.Compass>
</LinearLayout>

根据罗盘方向绘制abitmap

0 个答案: