ios - CAShapeLayer fillColor 不渲染

Question

我有一个接受 UIBezierPath 作为参数并相应地绘制形状的方法。如果我用纯色填充形状，它会很好地呈现，但如果我尝试使它成为带有 alpha 的颜色，我首先会收到 ARC 警告，要求更改代码并使用桥，然后填充颜色根本不会呈现。

这行得通，但不是我想要的:

standShapeLayer.fillColor = [[UIColor redColor] CGColor];

这会生成 ARC 警告“Objective C 指针类型 UIColor 隐式转换为 C 指针 CGColorRef”。

standShapeLayer.fillColor = [UIColor colorWithRed:0.2 green:0.66 blue:0.86 alpha:2.0f];

这会运行但没有 fillColor 应用于形状:

standShapeLayer.fillColor = (__bridge CGColorRef)([UIColor colorWithRed:0.2 green:0.66 blue:0.86 alpha:2.0f]);

下面是该方法的完整代码:

-(void)drawShape:(UIBezierPath *)standShape {

    [standShapeLayer removeFromSuperlayer];
    selectedStand = standShape;
    standShapeLayer = [CAShapeLayer layer];
    standShapeLayer.path = standShape.CGPath;
    standShapeLayer.fillColor = (__bridge CGColorRef)([UIColor colorWithRed:0.2 green:0.66 blue:0.86 alpha:2.0f]);
    NSLog(@"color = %@", standShapeLayer.fillColor); // This logs the correct colour which is not rendered.
    // standShapeLayer.fillColor = [[UIColor redColor] CGColor]; << This works but is not what I need.
    standShapeLayer.strokeColor = [[UIColor redColor] CGColor];
    standShapeLayer.lineWidth = 2;
    [_imageView.layer addSublayer:standShapeLayer];

}

我需要做什么才能让带有 alpha 的颜色填充 CAShapeLayer 形状？

Answer 1

您的 alpha 不正确。

alpha - The opacity value of the color object, specified as a value from 0.0 to 1.0.

努力改变

standShapeLayer.fillColor = (__bridge CGColorRef)([UIColor colorWithRed:0.2 green:0.66 blue:0.86 alpha:2.0f]);

到

standShapeLayer.fillColor = [[UIColor colorWithRed:0.2 green:0.66 blue:0.86 alpha:0.7f] CGColor];