如何突出显示 UIButton 子类

Question

我有一个UIButton子类，我在其中覆盖drawRect以获得自定义外观的按钮。

但是现在单元格不突出显示。

我该如何解决这个问题？

我已经为另一个自定义 drawRect 准备好了代码，以便在按下单元格时使用。

- (void)drawRect:(CGRect)rect
{
    //// General Declarations
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = UIGraphicsGetCurrentContext();
    //// Color Declarations
    UIColor* red = [UIColor colorWithRed: 1 green: 0 blue: 0 alpha: 1];
    CGFloat redRGBA[4];
    [red getRed: &redRGBA[0] green: &redRGBA[1] blue: &redRGBA[2] alpha: &redRGBA[3]];
    UIColor* darkRed = [UIColor colorWithRed: (redRGBA[0] * 0.8) green: (redRGBA[1] * 0.8) blue: (redRGBA[2] * 0.8) alpha: (redRGBA[3] * 0.8 + 0.2)];
    UIColor* lightRed = [UIColor colorWithRed: (redRGBA[0] * 0.8 + 0.2) green: (redRGBA[1] * 0.8 + 0.2) blue: (redRGBA[2] * 0.8 + 0.2) alpha: (redRGBA[3] * 0.8 + 0.2)];
    //// Gradient Declarations
    NSArray* redGradientColors = [NSArray arrayWithObjects: 
                                  (id)darkRed.CGColor, 
                                  (id)lightRed.CGColor, nil];
    CGFloat redGradientLocations[] = {0, 1};
    CGGradientRef redGradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)redGradientColors, redGradientLocations);
    //// Shadow Declarations
    CGColorRef shadow = [UIColor lightGrayColor].CGColor;
    CGSize shadowOffset = CGSizeMake(0, -0);
    CGFloat shadowBlurRadius = 1;
    CGColorRef shadow2 = [UIColor blackColor].CGColor;
    CGSize shadow2Offset = CGSizeMake(0, -0);
    CGFloat shadow2BlurRadius = 2;

    //// Rounded Rectangle Drawing
    UIBezierPath* roundedRectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(35, 5, 250, 50) cornerRadius: 6];
    CGContextSaveGState(context);
    CGContextSetShadowWithColor(context, shadow2Offset, shadow2BlurRadius, shadow2);
    CGContextSetFillColorWithColor(context, shadow2);
    [roundedRectanglePath fill];
    [roundedRectanglePath addClip];
    CGContextDrawLinearGradient(context, redGradient, CGPointMake(160, 55), CGPointMake(160, 5), 0);
    ////// Rounded Rectangle Inner Shadow
    CGRect roundedRectangleBorderRect = CGRectInset([roundedRectanglePath bounds], -shadowBlurRadius, -shadowBlurRadius);
    roundedRectangleBorderRect = CGRectOffset(roundedRectangleBorderRect, -shadowOffset.width, -shadowOffset.height);
    roundedRectangleBorderRect = CGRectInset(CGRectUnion(roundedRectangleBorderRect, [roundedRectanglePath bounds]), -1, -1);
    UIBezierPath* roundedRectangleNegativePath = [UIBezierPath bezierPathWithRect: roundedRectangleBorderRect];
    [roundedRectangleNegativePath appendPath: roundedRectanglePath];
    roundedRectangleNegativePath.usesEvenOddFillRule = YES;
    CGContextSaveGState(context);
    {
        CGFloat xOffset = shadowOffset.width + round(roundedRectangleBorderRect.size.width);
        CGFloat yOffset = shadowOffset.height;
        CGContextSetShadowWithColor(context,
                                    CGSizeMake(xOffset + copysign(0.1, xOffset), yOffset + copysign(0.1, yOffset)),
                                    shadowBlurRadius,
                                    shadow);
        [roundedRectanglePath addClip];
        CGAffineTransform transform = CGAffineTransformMakeTranslation(-round(roundedRectangleBorderRect.size.width), 0);
        [roundedRectangleNegativePath applyTransform: transform];
        [[UIColor grayColor] setFill];
        [roundedRectangleNegativePath fill];
    }
    CGContextRestoreGState(context);
    CGContextRestoreGState(context);
    [[UIColor blackColor] setStroke];
    roundedRectanglePath.lineWidth = 1;
    [roundedRectanglePath stroke];
    //// Cleanup
    CGGradientRelease(redGradient);
    CGColorSpaceRelease(colorSpace);
}

Answer 1

子类化UIButton没有意义，因为它是一种程序集/集群类。

我在子类化 UIControl 时创建自己的按钮并添加一些自定义行为时有最好的经验。

还要检查这个（你不应该子类UIButton）。

然后还要检查如何突出显示 UIControl 子类。

Answer 2

我认为您可以使用以下这些方法处理突出显示问题

- (BOOL)beginTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event;
- (BOOL)continueTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event;
- (void)endTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event;
- (void)cancelTrackingWithEvent:(UIEvent *)event;

您可以在这些方法中更改颜色或图像