ios - 选择时更改 UIBezierPath 颜色

Question

我在 - LayoutView 中画了 3 个正方形

- (void)drawRect:(CGRect)rect

    self.room1 = [UIBezierPath bezierPathWithRect:CGRectMake(81, 10, 60, 60)];
    [self.normalColor setFill];
    [self.room1 fill];
    [[UIColor blackColor]setStroke];
    self.room1.lineWidth = 1;
    [self.room1 stroke];

然后我找到正确的 UIBezierPath

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSLog(@"touch here");

    UITouch *touch = [touches anyObject];
    CGPoint touchPoint = [touch locationInView:self];
    if ([self.room1 containsPoint:touchPoint])
    {
        // do stuff
        NSLog(@"room1 %@" , self.room1);

        [[UIColor redColor] setFill];
        [self.room1 fill];
        [self setNeedsDisplay];
    } 
}

这是工作我触摸房间 1 和日志打印“room1”

但是如何更改 room1 的颜色？

目前我收到一个错误

：CGContextSetFillColorWithColor：无效的上下文0x0。这是一个严重的错误。...

谢谢你的帮助。

Answer 1

实现此目的的一种方法是在 touchesBegan 方法中跟踪选定状态，并将所有填充和 setFill 语句保存在 drawRect 中。在下面的示例中，我在正方形内的每次触摸切换选定状态，在蓝色和红色之间交替颜色。

@interface RDView ()
@property (strong,nonatomic) UIBezierPath *room1;
@property (strong,nonatomic) UIColor *normalColor;
@property (strong,nonatomic) UIColor *selectedColor;
@property (nonatomic) BOOL isSelected;
@end

@implementation RDView

-(id)initWithCoder:(NSCoder *)aDecoder {
    if (self = [super initWithCoder:aDecoder]) {
        self.normalColor = [UIColor blueColor];
        self.selectedColor = [UIColor redColor];
        self.isSelected = NO;
    }
    return self;
}

- (void)drawRect:(CGRect)rect {

    self.room1 = [UIBezierPath bezierPathWithRect:CGRectMake(81, 10, 60, 60)];
    UIColor *colorToUse = (self.isSelected)? self.selectedColor : self.normalColor;
    [colorToUse setFill];
    [self.room1 fill];
    [[UIColor blackColor]setStroke];
    self.room1.lineWidth = 1;
    [self.room1 stroke];
}


- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    CGPoint touchPoint = [touches.anyObject locationInView:self];
    if ([self.room1 containsPoint:touchPoint]){
        self.isSelected = ! self.isSelected;
        [self setNeedsDisplay];
    }
}