Question

当我在xos中为ios绘制一个形状时，如何更改最终绘制形状的颜色？

- (void) drawArrowWithContext:(CGContextRef)context atPoint:(CGPoint)startPoint withSize:   (CGSize)size lineWidth:(float)width arrowHeight:(float)aheight
{
float width_wing = (size.width-width)/2;
float main = size.height-aheight;
CGPoint rectangle_points[] =
{
    CGPointMake(startPoint.x + width_wing, startPoint.y + 0.0),
    CGPointMake(startPoint.x + width_wing, startPoint.y + main),
    CGPointMake(startPoint.x + 0.0, startPoint.y + main), // left point
    CGPointMake(startPoint.x + size.width/2, startPoint.y + size.height),

    CGPointMake(startPoint.x + size.width, startPoint.y + main), // right point

    CGPointMake(startPoint.x + size.width-width_wing, startPoint.y + main),

    CGPointMake(startPoint.x + size.width-width_wing, startPoint.y + 0.0),
    CGPointMake(startPoint.x + width_wing, startPoint.y + 0.0),
};

CGContextAddLines(context, rectangle_points, 8);

CGContextFillPath(context);
}

默认情况下，此箭头的颜色为黑色，但我希望用户能够将其更改为黑色，白色或红色。我怎么能这样做？

Answer 1

我认为您要找的是CGContextSetRGBFillColor或CGContextSetRGBStrokeColor

- (void) drawArrowWithContext:(CGContextRef)context atPoint:(CGPoint)startPoint withSize: (CGSize)size lineWidth:(float)width arrowHeight:(float)aheight andColor:(UIColor *)color
{
float width_wing = (size.width-width)/2;
float main = size.height-aheight;

CGContextSetRGBFillColor(context,color.CGColor);
CGContextSetRGBStrokeColor(context,color.CGColor);

CGPoint rectangle_points[] =
{
    CGPointMake(startPoint.x + width_wing, startPoint.y + 0.0),
    CGPointMake(startPoint.x + width_wing, startPoint.y + main),
    CGPointMake(startPoint.x + 0.0, startPoint.y + main), // left point
    CGPointMake(startPoint.x + size.width/2, startPoint.y + size.height),

    CGPointMake(startPoint.x + size.width, startPoint.y + main), // right point

    CGPointMake(startPoint.x + size.width-width_wing, startPoint.y + main),

    CGPointMake(startPoint.x + size.width-width_wing, startPoint.y + 0.0),
    CGPointMake(startPoint.x + width_wing, startPoint.y + 0.0),
};

CGContextAddLines(context, rectangle_points, 8);

CGContextFillPath(context);
}

Answer 2

您需要使用新颜色重绘它。箭头不作为具有可以动态更改的属性的对象存在。

因此，请更改@selector以接受通过CGContextSetRGBFillColor或CGContextSetRGBStrokeColor应用的颜色参数。这可以是CGColor，也可以是整数，您可以在switch语句中使用它来从某些预定义的颜色中进行选择。

改变绘制形状iOS的颜色

2 个答案: