Android重绘矩形填充白色

Question

I'm trying to create a custom view which reads a colour from my arduino via bluetooth and displays that colour on my phone screen. I'm able to successfuly read a colour from the bluetooth device through a thread which I have created to continually read data from the arduino. I have also got another thread running on a loop to see if that colour has changed and if it has, to change the global variable chosenColor accordingly:

       while(true){
            int newColor = device.activeSensorColor;
            if(chosenColor != newColor){
                chosenColor = newColor;
                invalidater.post(invalidating);
            }
        }

After it has done this, it uses a Handler on the UI thread to call invalidate(); and to redraw the form. The following void is always called:

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

    canvas.drawRect(bounds, boxPaint);

    samplePaint.setColor(chosenColor);

    canvas.drawRect(colorSample, samplePaint);

    canvas.drawText(buttonText, (width - height) / 2 + height, height / 2, textPaint);

    canvas.drawRect(sampleBorder, borderPaint);
}

And this will without fail set the colour of the box to white. I've been trying to figure this out for hours, but every time I try something, the colour of the sample rectangle will be white, no matter what colour is being picked up from the arduino. Has anyone got any ideas? Thanks.

Answer 1

I've figured it out! I can't believe I was so stupid! After the colour was being read from my arduino, I was saving it to an integer using the Color.argb(a,r,g,b); method. The device wasn't sending me an alpha value, so this was zero and the color I was creating became transparrent. I'm now using the Color.rgb(r,g,b) method and this is working great :)