Android通过自定义View实现心形（贝塞尔曲线）

通过继承View实现的❤形

在绘制心形需要Path类中的两个重要方法分别是：moveTo、cubicTo

moveTo 不会进行绘制，只用于移动移动画笔。

lineTo 用于进行直线绘制。

quadTo 用于绘制圆滑曲线，即贝塞尔曲线。

cubicTo 同样是用来实现贝塞尔曲线的。

具体实现：

public class HeartView extends View {    private int mMeasureWidth;    private int mWidthMode;    private int mMeasureHeight;    private int mHeightMode;    private Paint paint;    public HeartView(Context context) {        super(context);    }    public HeartView(Context context, AttributeSet attrs) {        super(context, attrs);        paint = new Paint();//实例画笔        paint.setAntiAlias(true);//抗锯齿        paint.setStrokeWidth(2);//画笔宽度        paint.setColor(Color.RED);//画笔颜色        paint.setStyle(Paint.Style.FILL);//画笔样式    }    /**     * 测量     */    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        mWidthMode = MeasureSpec.getMode(widthMeasureSpec);        mHeightMode = MeasureSpec.getMode(heightMeasureSpec);        mMeasureWidth = MeasureSpec.getSize(widthMeasureSpec);        mMeasureHeight = MeasureSpec.getSize(heightMeasureSpec);        if (mWidthMode == MeasureSpec.AT_MOST && mHeightMode == MeasureSpec.AT_MOST) {            setMeasuredDimension(200, 200);        } else if (mWidthMode == MeasureSpec.AT_MOST) {            setMeasuredDimension(200, mMeasureHeight);        } else if (mHeightMode == MeasureSpec.AT_MOST) {            setMeasuredDimension(mMeasureWidth, 200);        } else {            setMeasuredDimension(mMeasureWidth, mMeasureHeight);        }    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        int width = getWidth();//获取屏幕宽        int height = getHeight();//获取屏幕高        /**         *  绘制心形         */        //左半面        Path path = new Path();        path.moveTo(width / 2, height / 4);        path.cubicTo((width * 6) / 7, height / 9, (width * 12) / 13, (height * 2) / 5, width / 2, (height * 7) / 12);        canvas.drawPath(path, paint);        //右半面        Path path2 = new Path();        path2.moveTo(width / 2, height / 4);        path2.cubicTo(width / 7, height / 9, width / 13, (height * 2) / 5, width / 2, (height * 7) / 12);        canvas.drawPath(path2, paint);    }}

在布局中引入一下

实现效果：

通过继承View实现的❤形

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