标签:style blog http color get 使用
解析UIControl
从下图可以看出,UIControl继承自UIView,添加了响应事件功能.
UIButton之所以能响应各种各样的事件是因为继承自UIControl
使用UIControl可以精确的控制按钮事件,我用定制UIControlEventValueChanged来进行说明.
YXControl.h + YXControl.m
// // YXControl.h // UIControl // // Copyright (c) 2014年 Y.X. All rights reserved. // #import <UIKit/UIKit.h> @interface YXControl : UIControl @property (nonatomic, strong) UIImage *yesImage; @property (nonatomic, strong) UIImage *noImage; - (void)exchange; @end
// // YXControl.m // UIControl // // Copyright (c) 2014年 Y.X. All rights reserved. // #import "YXControl.h" @interface YXControl () @property (nonatomic, strong) UIImageView *YesImageView; @property (nonatomic, strong) UIImageView *NoImageView; @end @implementation YXControl #pragma mark - 重写 getter setter 方法 @synthesize yesImage = _yesImage; @synthesize noImage = _noImage; - (UIImage *)yesImage { return _yesImage; } - (void)setYesImage:(UIImage *)yesImage { _yesImage = yesImage; _YesImageView.image = yesImage; } - (UIImage *)noImage { return _noImage; } - (void)setNoImage:(UIImage *)noImage { _noImage = noImage; _NoImageView.image = noImage; } #pragma mark - 初始化 - (id)initWithFrame:(CGRect)frame { self = [super initWithFrame:frame]; if (self) { _YesImageView = [[UIImageView alloc] initWithFrame:frame]; _NoImageView = [[UIImageView alloc] initWithFrame:frame]; [self addSubview:_YesImageView]; [self addSubview:_NoImageView]; } return self; } #pragma mark - UIControl事件 - (BOOL)beginTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event { // 获取触摸点坐标 CGPoint p = [touch locationInView:self]; NSLog(@"begin %@", NSStringFromCGPoint(p)); return YES; } - (BOOL)continueTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event { // 获取触摸点坐标 CGPoint p = [touch locationInView:self]; NSLog(@"continue %@", NSStringFromCGPoint(p)); return YES; } - (void)endTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event { // 获取触摸点坐标 CGPoint p = [touch locationInView:self]; NSLog(@"end %@", NSStringFromCGPoint(p)); // 判断触摸点是否超出了这个view的范围 if (p.x >= 0 && p.x <= self.bounds.size.width && p.y >= 0 && p.y <= self.bounds.size.height) { // 发送事件 [self sendActionsForControlEvents:UIControlEventValueChanged]; } } - (void)cancelTrackingWithEvent:(UIEvent *)event { } - (void)exchange { [self bringSubviewToFront:self.subviews[0]]; } @end
用于测试用的图片
结果如图下图所示:
// // RootViewController.m // UIControl // // Copyright (c) 2014年 Y.X. All rights reserved. // #import "RootViewController.h" #import "YXControl.h" @interface RootViewController () @end @implementation RootViewController - (void)viewDidLoad { [super viewDidLoad]; // 初始化UIControl YXControl *controlView = [[YXControl alloc] initWithFrame:CGRectMake(0, 0, 100, 100)]; controlView.backgroundColor = [UIColor blackColor]; controlView.center = self.view.center; controlView.yesImage = [UIImage imageNamed:@"yes"]; controlView.noImage = [UIImage imageNamed:@"no"]; [self.view addSubview:controlView]; // 添加响应事件 [controlView addTarget:self action:@selector(controlEvent:) forControlEvents:UIControlEventValueChanged]; } - (void)controlEvent:(YXControl *)control { [control exchange]; } @end
以下三个方法非常重要:
beginTrackingWithTouch: 触摸事件刚刚开始时执行(1次)
continueTrackingWithTouch: 滑动手指后将会一直执行(多次)
endTrackingWithTouch: 松开手指后执行(1次)
以下两个地方也是需要注意的哦:
1. 发送UIControlEventValueChanged事件
2. 注册对应的UIControlEventValueChanged事件
只有这样子,两者之间才能通过addTarget:action:forControlEvents:联系起来.
以下这个小细节也是非常令人意外的,UIControlEventValueChanged这个值是非常独特的呢.
如果使用UIControlEventTouchUpInside,这个事件是UIControl自动发的,不需要你管哦(也就是说不需要你执行sendActionsForControlEvents:)
标签:style blog http color get 使用
原文地址:http://www.cnblogs.com/YouXianMing/p/3797226.html