UIView 没有得到 touchesbegan 调用答案

【问题标题】：UIView not getting touchesbegan calledUIView 没有得到 touchesbegan 调用
【发布时间】：2015-10-26 01:12:31
【问题描述】：

还有许多其他问题，但似乎没有一个解决方案对我有用。我对 iOS 很陌生 - 目前正在解决 Big Nerd Ranch iOS 编程书中的一个问题。

我发现的大多数 SO 都说问题最终是 userInteractionEnabled = YES 丢失。或者视图的背景设置为transparent。但是移除透明背景并设置userInteractionEnabled = YES 并没有导致事件触发。有什么我想念的想法吗？

AppDelegate.m：

#import "AppDelegate.h"
#import "BNRHypnosisView.h"
#import "ViewController.h"

@interface AppDelegate ()

@end

@implementation AppDelegate


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    CGRect firstFrame = self.window.bounds;

    BNRHypnosisView *firstView = [[BNRHypnosisView alloc] initWithFrame:firstFrame];
    firstView.userInteractionEnabled = YES;

    ViewController *controller = [[ViewController alloc] init];
    [self.window setRootViewController:controller];
    [self.window addSubview:firstView];

    self.window.backgroundColor = [UIColor whiteColor];

    [self.window makeKeyAndVisible];

    return YES;
}

BNRHypnosisView.m：

#import "BNRHypnosisView.h"

@interface BNRHypnosisView()

@property (strong, nonatomic) UIColor *circleColor;

@end

@implementation BNRHypnosisView
-(void)drawRect:(CGRect)rect {
    CGRect bounds = self.bounds;

    CGPoint center;
    center.x = bounds.origin.x + bounds.size.width / 2.0;
    center.y = bounds.origin.y + bounds.size.height / 2.0;

    float maxRadius = hypot(bounds.size.width, bounds.size.height) / 2.0;
    UIBezierPath *path = [[UIBezierPath alloc] init];

    for (float currentRadius = maxRadius; currentRadius > 0; currentRadius -=20) {
        [path moveToPoint:CGPointMake(center.x + currentRadius, center.y)];

        [path addArcWithCenter:center radius:currentRadius startAngle:0.0 endAngle:M_PI * 2.0 clockwise:YES];
    }

    path.lineWidth = 10;

    [self.circleColor setStroke];

    [path stroke];
}

-(instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        self.backgroundColor = [UIColor clearColor];
        self.circleColor = [UIColor lightGrayColor];
    }
    return self;
}

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    NSLog(@"%@ was touched", self);

    float red = (arc4random() % 100) / 100.0;
    float green = (arc4random() % 100) / 100.0;
    float blue = (arc4random() % 100) / 100.0;

    UIColor *randomColor = [UIColor colorWithRed:red green:green blue:blue alpha:1.0];

    self.circleColor = randomColor;
}

应用截图：

视图调试器截图

【问题讨论】：

你还有其他关于催眠观点的观点吗？你能通过在视图调试器中看到它来确认它吗！！！！
嗯。这是我第一次使用视图调试器，我刚刚发布的截图中的UIView实际上是在催眠视图前面吗？
你贴的截图是在催眠视图上面吗？
看起来是这样的？但是我没有在我的代码中的任何地方添加 UIView，我可以说，Hypnosis 视图是 UIView 的子类 :(。知道这可能来自哪里吗？控制器中是否添加了某种默认视图？
这可能与幕后还有故事板有关吗？

标签： ios objective-c uiview touchesbegan

【解决方案1】：

您将BNRHypnosisView 添加为窗口的子视图。稍后，当窗口即将出现在屏幕上时，它会将其根视图控制器的视图作为另一个子视图添加到您的催眠视图前面。您可以在视图层次结构中看到这一点，它在您的BNRHypnosisView 之后显示一个普通的UIView。列表中较晚的视图比列表中较早的视图“位于”或“更靠近屏幕”。

试试这个：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];

    ViewController *controller = [[ViewController alloc] init];
    [self.window setRootViewController:controller];

    BNRHypnosisView *firstView = [[BNRHypnosisView alloc] initWithFrame:controller.view.bounds];
    firstView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    firstView.userInteractionEnabled = YES;
    [controller.view addSubview:firstView];

    [self.window makeKeyAndVisible];
    return YES;
}

【讨论】：