java - Android位图着色

Question

我刚刚在学习 Android 的媒体功能，我可能对位图有一些疑问，这里是应用程序:

我的问题:我如何制作应用程序，以便在单击圆圈内某处时用特定颜色填充它？这是我使用的代码:

public class DrawingView extends View
{

    private Path drawPath;
    private Paint drawPaint, canvasPaint;
    private int paintColor = 0xFF660000;
    private Canvas drawCanvas;
    private Bitmap canvasBitmap;
    private Bitmap newBitMap;

    public DrawingView(Context context, AttributeSet attrs){
        super(context, attrs);
        setupDrawing();
    }
    private void setupDrawing(){
        drawPath = new Path();
        drawPaint = new Paint();

        drawPaint.setColor(paintColor);
        drawPaint.setAntiAlias(true);
        drawPaint.setStrokeWidth(20);
        drawPaint.setStyle(Paint.Style.STROKE);
        drawPaint.setStrokeJoin(Paint.Join.ROUND);
        drawPaint.setStrokeCap(Paint.Cap.ROUND);
        drawPaint.setStyle(Paint.Style.FILL);
        canvasPaint = new Paint(Paint.DITHER_FLAG);
    }
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        newBitMap = BitmapFactory.decodeResource(getResources(),R.drawable.myb);
        canvasBitmap = newBitMap.copy(Bitmap.Config.ARGB_8888, true);
        drawCanvas = new Canvas(canvasBitmap);
    }
    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
        canvas.drawPath(drawPath, drawPaint);
    }
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        float touchX = event.getX();
        float touchY = event.getY();
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                drawPath.moveTo(touchX, touchY);
                break;
            case MotionEvent.ACTION_MOVE:
                drawPath.lineTo(touchX, touchY);
                break;
            case MotionEvent.ACTION_UP:
                drawCanvas.drawPath(drawPath, drawPaint);
                drawPath.reset();
                break;
            default:
                return false;
        }
        invalidate();
        return true;
    }
    public void setColor(String newColor){
        invalidate();
        paintColor = Color.parseColor(newColor);
        drawPaint.setColor(paintColor);
//set color
    }


public class MainActivity extends AppCompatActivity {
    private DrawingView drawView;
    private ImageButton currPaint;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        drawView = (DrawingView)findViewById(R.id.drawing);
        LinearLayout paintLayout = (LinearLayout)findViewById(R.id.paint_colors);
        currPaint = (ImageButton)paintLayout.getChildAt(0);
        currPaint.setImageDrawable(getResources().getDrawable(R.drawable.paint_pressed));

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
    public void paintClicked(View view){
        if(view!=currPaint){
            ImageButton imgView = (ImageButton)view;
            String color = view.getTag().toString();
            drawView.setColor(color);
            imgView.setImageDrawable(getResources().getDrawable(R.drawable.paint_pressed));
            currPaint.setImageDrawable(getResources().getDrawable(R.drawable.paint));
            currPaint=(ImageButton)view;
        }

    }

}

Answer 1

在 onDraw 期间，您应该执行另一遍以使用相同的路径绘制填充，但使用不同的颜料。

例如:

// setup stroke
drawPaint = new Paint();
drawPaint.setColor(paintColor);
drawPaint.setAntiAlias(true);
drawPaint.setStrokeWidth(20);
drawPaint.setStyle(Paint.Style.STROKE);
drawPaint.setStrokeJoin(Paint.Join.ROUND);
drawPaint.setStrokeCap(Paint.Cap.ROUND);

// setup fill
fillPaint = new Paint();
fillPaint.setColor(fillColor);
fillPaint.setAntiAlias(true);
fillPaint.setStyle(Paint.Style.FILL);

然后在抽签里面

@Override
protected void onDraw(Canvas canvas) {
    canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint); // canvas
    canvas.drawPath(drawPath, fillPaint); // fill
    canvas.drawPath(drawPath, drawPaint); // stroke
}