Question

我已经扩展了SubsamplingScaleImageView以在文档中建议创建PinView。我能够在适当的位置绘制品脱。但我面临的问题是：当我尝试绘制循环时，Pin会丢失。我验证了OnDraw是在主线程上调用的。

以下是我正在使用的代码

public class PinView extends SubsamplingScaleImageView {

    private PointF sPin;
    private Bitmap pin;
    private PointF sBlueDot;
    private Bitmap blueDot;

    public PinView(Context context) {
        this(context, null);
    }

    public PinView(Context context, AttributeSet attr) {
        super(context,attr);
        initialise();
        initialiseBlueDot()
    }

    public void setPin(PointF sPin) {
        this.sPin = sPin;
        initialise();
        invalidate();
    }

    public void setBlueDot(PointF sPin) {
        this.sBlueDot = sPin;
        initialiseBlueDot();
        invalidate();
    }

    public PointF getPin() {
        return sPin;
    }

    private void initialise() {
        float density = getResources().getDisplayMetrics().densityDpi;
        pin = BitmapFactory.decodeResource(this.getResources(), drawable.pushpin_blue);
        float w = (density/420f) * pin.getWidth();
        float h = (density/420f) * pin.getHeight();
        pin = Bitmap.createScaledBitmap(pin, (int)w, (int)h, true);
    }

    private void initialiseBlueDot() {
        float density = getResources().getDisplayMetrics().densityDpi;
        blueDot = BitmapFactory.decodeResource(this.getResources(), drawable.pushpin_blue);
        float w = (density/420f) * blueDot.getWidth();
        float h = (density/420f) * blueDot.getHeight();
        blueDot = Bitmap.createScaledBitmap(blueDot, (int)w, (int)h, true);
    }  

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        // Don't draw pin before image is ready so it doesn't move around during setup.
        if (!isReady()) {
            return;
        }

        Paint paint = new Paint();
        paint.setAntiAlias(true);

        if (sPin != null && pin != null) {
            PointF vPin = sourceToViewCoord(sPin);
            float vX = vPin.x - (pin.getWidth()/2);
            float vY = vPin.y - pin.getHeight();
            canvas.drawBitmap(pin, vX, vY, paint);
        }

        if (sBlueDot != null && pin != null) {
            PointF vPin = sourceToViewCoord(sBlueDot);
            float vX = vPin.x - (blueDot.getWidth()/2);
            float vY = vPin.y - blueDot.getHeight();
            canvas.drawBitmap(blueDot, vX, vY, paint);
        }
    }
}

Answer 1

我自己修好了。问题出在XY和源xy点上。使用viewToSourceCoord（）来获取正确的位置点。

PinView不会在循环中绘制

1 个答案: