Obj-C - touchesBegan：在定义的区域

Posted 2023-02-26

【中文标题】Obj-C - touchesBegan：在定义的区域

【英文标题】：Obj-C - touchesBegan: on defined area

【发布时间】：2014-08-19 10:05:29

【问题描述】：

我是Objective-C的新手，有一点开发经验，但不多。

我目前正在学习自定义绘图、处理视图和了解视图控制器。

我只是想制作一个应用程序，当我触摸它时矩形会改变颜色。我的颜色改变部分没问题，但我目前的问题是我希望颜色只有在我触摸矩形内部时才会改变。目前发生的情况是，无论我触摸屏幕，颜色都会发生变化。

这是我的代码： NICRectangleView.m

#import "NICRectangleView.h"

@implementation NICRectangleView

- (id)initWithFrame:(CGRect)frame

self = [super initWithFrame:frame];
if (self) 
    // Initialization code
    self.rectColor = [UIColor redColor];

return self;



// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect

// Drawing code
CGRect bounds = CGRectMake(50, 50, 200, 100);

UIBezierPath *rectPath = [UIBezierPath bezierPathWithRect:bounds];

[self.rectColor setFill];

[rectPath fill];




-(void)setRectColor:(UIColor *)rectColor

    _rectColor = rectColor;
    [self setNeedsDisplay];


-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

NSLog(@"%@ was touched", self);

if (self.rectColor == [UIColor redColor]) 
    self.rectColor = [UIColor blueColor];
 else 
    self.rectColor = [UIColor redColor];



@end

NICRectangleViewController.m：

#import "NICRectangleViewController.h"
#import "NICRectangleView.h"

@interface NICRectangleViewController ()

@end

@implementation NICRectangleViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) 
        // Custom initialization
    
    return self;


-(void)loadView

    NICRectangleView *rectView = [[NICRectangleView alloc]init];

    self.view = rectView;

    self.view.backgroundColor = [UIColor whiteColor];


- (void)viewDidLoad

    [super viewDidLoad];
    // Do any additional setup after loading the view.


- (void)didReceiveMemoryWarning

    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.

还有我的 AppDelegate.m：

#import "NICAppDelegate.h"
#import "NICRectangleView.h"
#import "NICRectangleViewController.h"

@implementation NICAppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.

    NICRectangleViewController *rvc = [[NICRectangleViewController alloc]init];

    self.window.rootViewController = rvc;

    self.window.backgroundColor = [UIColor whiteColor];

    [self.window makeKeyAndVisible];

    return YES;

我是否认为这是因为当我将 windows rootViewController 设置为我的 RectangleViewController 时，它会自动设置它以便控制器管理的视图是全屏的？

我该如何更改？

非常感谢您阅读本文。

最好的问候，

NC

【问题讨论】：

看看那里：***.com/questions/14856906/… 以了解您“触摸”的位置，并按照您的意愿行事。

【参考方案1】：

试试这样的

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 

  // Detect touch anywhere
  UITouch *touch = [[event allTouches]  anyObject];

  // Get the specific point that was touched
  CGPoint point = [touch locationInView:self.view]; 
  NSLog(@"pointx: %f pointy:%f", point.x, point.y);

  // See if the point touched is within these rectangular bounds
  if (CGRectContainsPoint(CGRectMake(50, 50, 200, 100), point))
  
    //do something...
   

希望它有效。

【讨论】：

酷，完美！唯一的事情是，我必须将 [touches anyObject] 更改为 [[event allTouches] anyObject] 才能使其工作，否则它无法识别触摸的坐标。无论如何，感谢您快速准确的回答！