Question

我正在使用一个简单的罗盘应用程序。我需要设置罗盘视图和传感器活动，我选择罗盘视图类。但它只是为罗盘视图画一个圆圈和一条线。我需要通过将此圆圈和线条替换为我自己的可绘制图像来自定义此视图，有人请帮我修复此问题。

我的观点类

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;

public class MyCompassView extends View {

  private Paint paint;
  private float position = 0;

  public MyCompassView(Context context) {
    super(context);
    init();
  }

  private void init() {
    paint = new Paint();
    paint.setAntiAlias(true);
    paint.setStrokeWidth(2);
    paint.setTextSize(25);
    paint.setStyle(Paint.Style.STROKE);
    paint.setColor(Color.WHITE);
  }

  @Override
  protected void onDraw(Canvas canvas) {
    int xPoint = getMeasuredWidth() / 2;
    int yPoint = getMeasuredHeight() / 2;

    float radius = (float) (Math.max(xPoint, yPoint) * 0.6);
    canvas.drawCircle(xPoint, yPoint, radius, paint);
    canvas.drawRect(0, 0, getMeasuredWidth(), getMeasuredHeight(), paint);

    // 3.143 is a good approximation for the circle
    canvas.drawLine(xPoint,
        yPoint,
        (float) (xPoint + radius
            * Math.sin((double) (-position) / 180 * 3.143)),
        (float) (yPoint - radius
            * Math.cos((double) (-position) / 180 * 3.143)), paint);

    canvas.drawText(String.valueOf(position), xPoint, yPoint, paint);
  }

  public void updateData(float position) {
    this.position = position;
    invalidate();
  }

}

Answer 1

以上代码已被弃用。更新的代码可用here

XML布局activty_main

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#fff" >
    <TextView
        android:id="@+id/tvHeading"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="40dp"
        android:layout_marginTop="20dp"
        android:text="Heading: 0.0" />
    <ImageView
        android:id="@+id/imageViewCompass"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/tvHeading"
        android:layout_centerHorizontal="true"
        android:src="@drawable/img_compass" />
</RelativeLayout>

<强> MainActivity

public class MainActivity extends Activity implements SensorEventListener {

    // define the display assembly compass picture
    private ImageView image;

    // record the compass picture angle turned
    private float currentDegree = 0f;

    // device sensor manager
    private SensorManager mSensorManager;

    TextView tvHeading;

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

        // 
        image = (ImageView) findViewById(R.id.main_iv);

        // TextView that will tell the user what degree is he heading
        tvHeading = (TextView) findViewById(R.id.tvHeading);

        // initialize your android device sensor capabilities
        mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    }

    @Override
    protected void onResume() {
        super.onResume();

        // for the system's orientation sensor registered listeners
        mSensorManager.registerListener(this, mSensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION),
                SensorManager.SENSOR_DELAY_GAME);
    }

    @Override
    protected void onPause() {
        super.onPause();

        // to stop the listener and save battery
        mSensorManager.unregisterListener(this);
    }

    @Override
    public void onSensorChanged(SensorEvent event) {

        // get the angle around the z-axis rotated
        float degree = Math.round(event.values[0]);

        tvHeading.setText("Heading: " + Float.toString(degree) + " degrees");

        // create a rotation animation (reverse turn degree degrees)
        RotateAnimation ra = new RotateAnimation(
                currentDegree, 
                -degree,
                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 = -degree;

    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // not in use
    }
}

如何在android中制作自定义指南针视图

1 个答案: