Android 如何用不同的颜色画线？

我开发了一个在屏幕上绘制线条的应用程序。我想对线条使用不同的颜色，但所有线条都以相同的颜色显示

我的代码中有一个颜色选择器来更改颜色，每次我都想通过选择颜色来绘制不同颜色的线条，但现在因为我正在构建线条并渲染它。当我最初选择红色并绘制线条，然后选择蓝色并绘制线条时，现在旧的线条也变为蓝色而不是红色，然而，我希望红色保持红色，蓝色保持红色，有人能帮忙吗

我的代码如下

MyDemo.java：

MyImageView.java：

ColorPickerDialog.java：

---

我不确定，但你的onDraw方法有问题

Paint paint = createPen(colorPicked);
paint.setStyle(Paint.Style.STROKE);
for (Path path : paths) {
    canvas.drawPath(path, paint);
}

首先选择一种颜色，这是您最后选择的颜色，然后使用相同的颜色绘制每个路径。

---

我认为解决这个问题的方法是创建一个颜色数组，其中包含您创建的每个路径的颜色，并在绘制每个路径之前选择相应的颜色

  @Override
  protected void onDraw(Canvas canvas) {

    canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
    int colorPicked = MainActivity.selectedColor;

    paint1 = createPen(colorPicked);
     for (Path p : paths){       
         canvas.drawPath(p, paint1);
         paint1.setColor(colorPicked);
     }

}

private Paint createPen(int color) {
    // TODO Auto-generated method stub

    paint1 = new Paint();
    paint1.setAntiAlias(true);
    paint1.setDither(true);
    paint1.setStyle(Paint.Style.STROKE);
    paint1.setStrokeJoin(Paint.Join.ROUND);
    paint1.setStrokeCap(Paint.Cap.ROUND);
    paint1.setStrokeWidth(3);
    return paint1;
}

---

任何人都知道，然后建议我参考一些网站。。。

public class ColorPickerDialog extends Dialog {

    public interface OnColorChangedListener {
        void colorChanged(int color);

    }

    private final OnColorChangedListener mListener;
    private final int mInitialColor;

    private static class ColorPickerView extends View {
        private final Paint mPaint;
        private final Paint mCenterPaint;
        private final int[] mColors;
        private final OnColorChangedListener mListener;

        ColorPickerView(Context c, OnColorChangedListener l, int color) {
            super(c);
            mListener = l;
            mColors = new int[] { 0xFFFF0000, 0xFFFF00FF, 0xFF0000FF,
                    0xFF00FFFF, 0xFF00FF00, 0xFFFFFF00, 0xFFFF0000 };
            Shader s = new SweepGradient(0, 0, mColors, null);

            mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            mPaint.setShader(s);
            mPaint.setStyle(Paint.Style.STROKE);
            mPaint.setStrokeWidth(32);

            mCenterPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            mCenterPaint.setColor(color);
            mCenterPaint.setStrokeWidth(5);
        }

        private boolean mTrackingCenter;
        private boolean mHighlightCenter;

        @Override
        protected void onDraw(Canvas canvas) {
            float r = CENTER_X - mPaint.getStrokeWidth() * 0.5f;

            canvas.translate(CENTER_X, CENTER_X);

            canvas.drawOval(new RectF(-r, -r, r, r), mPaint);
            canvas.drawCircle(0, 0, CENTER_RADIUS, mCenterPaint);

            if (mTrackingCenter) {
                int c = mCenterPaint.getColor();
                mCenterPaint.setStyle(Paint.Style.STROKE);

                if (mHighlightCenter) {
                    mCenterPaint.setAlpha(0xFF);
                } else {
                    mCenterPaint.setAlpha(0x80);
                }
                canvas.drawCircle(0, 0, CENTER_RADIUS
                        + mCenterPaint.getStrokeWidth(), mCenterPaint);

                mCenterPaint.setStyle(Paint.Style.FILL);
                mCenterPaint.setColor(c);
            }
        }

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            setMeasuredDimension(CENTER_X * 2, CENTER_Y * 2);
        }

        private static final int CENTER_X = 100;
        private static final int CENTER_Y = 100;
        private static final int CENTER_RADIUS = 32;

        private int ave(int s, int d, float p) {
            return s + java.lang.Math.round(p * (d - s));
        }

        private int interpColor(int colors[], float unit) {
            if (unit <= 0)
                return colors[0];
            if (unit >= 1)
                return colors[colors.length - 1];

            float p = unit * (colors.length - 1);
            int i = (int) p;
            p -= i;

            // now p is just the fractional part [0...1) and i is the index
            int c0 = colors[i];
            int c1 = colors[i + 1];
            int a = ave(Color.alpha(c0), Color.alpha(c1), p);
            int r = ave(Color.red(c0), Color.red(c1), p);
            int g = ave(Color.green(c0), Color.green(c1), p);
            int b = ave(Color.blue(c0), Color.blue(c1), p);

            return Color.argb(a, r, g, b);
        }

        private static final float PI = 3.1415926f;

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            float x = event.getX() - CENTER_X;
            float y = event.getY() - CENTER_Y;
            boolean inCenter = java.lang.Math.sqrt(x * x + y * y) <= CENTER_RADIUS;

            switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mTrackingCenter = inCenter;
                if (inCenter) {
                    mHighlightCenter = true;
                    invalidate();
                    break;
                }
            case MotionEvent.ACTION_MOVE:
                if (mTrackingCenter) {
                    if (mHighlightCenter != inCenter) {
                        mHighlightCenter = inCenter;
                        invalidate();
                    }
                } else {
                    float angle = (float) java.lang.Math.atan2(y, x);
                    // need to turn angle [-PI ... PI] into unit [0....1]
                    float unit = angle / (2 * PI);
                    if (unit < 0) {
                        unit += 1;
                    }
                    mCenterPaint.setColor(interpColor(mColors, unit));
                    invalidate();
                }
                break;
            case MotionEvent.ACTION_UP:
                if (mTrackingCenter) {
                    if (inCenter) {
                        mListener.colorChanged(mCenterPaint.getColor());

                    }
                    mTrackingCenter = false; // so we draw w/o halo
                    invalidate();
                }
                break;
            }
            return true;
        }
    }

    public ColorPickerDialog(Context context, OnColorChangedListener listener,
            int initialColor) {
        super(context);

        mListener = listener;
        mInitialColor = initialColor;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        OnColorChangedListener l = new OnColorChangedListener() {
            public void colorChanged(int color) {
                mListener.colorChanged(color);
                dismiss();
            }
        };

        LinearLayout layout = new LinearLayout(getContext());
        layout.setOrientation(LinearLayout.VERTICAL);
        layout.setGravity(Gravity.CENTER);
        layout.setPadding(10, 10, 10, 10);
        layout.addView(new ColorPickerView(getContext(), l, mInitialColor),
                new LinearLayout.LayoutParams(
                        LinearLayout.LayoutParams.WRAP_CONTENT,
                        LinearLayout.LayoutParams.WRAP_CONTENT));
        setContentView(layout);
        setTitle("Pick a Color");
    }
}

Paint paint = createPen(colorPicked);
paint.setStyle(Paint.Style.STROKE);
for (Path path : paths) {
    canvas.drawPath(path, paint);
}

  @Override
  protected void onDraw(Canvas canvas) {

    canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
    int colorPicked = MainActivity.selectedColor;

    paint1 = createPen(colorPicked);
     for (Path p : paths){       
         canvas.drawPath(p, paint1);
         paint1.setColor(colorPicked);
     }

}

private Paint createPen(int color) {
    // TODO Auto-generated method stub

    paint1 = new Paint();
    paint1.setAntiAlias(true);
    paint1.setDither(true);
    paint1.setStyle(Paint.Style.STROKE);
    paint1.setStrokeJoin(Paint.Join.ROUND);
    paint1.setStrokeCap(Paint.Cap.ROUND);
    paint1.setStrokeWidth(3);
    return paint1;
}