級別：★★☆☆☆
標簽：「UIButton」「UIControlEvents」
作者： WYW
審校： QiShare團隊

大家好，今天小編帶大家研究一下UIButton里各種UIControlEvents的具體區別。
首先，我們先看下蘋果官方對UIControlEvents的定義。

UIControlEvents 相關位移枚舉

typedef NS_OPTIONS(NSUInteger, UIControlEvents) {
        UIControlEventTouchDown                                         = 1 <<  0,      // on all touch downs
        UIControlEventTouchDownRepeat                                   = 1 <<  1,      // on multiple touchdowns (tap count > 1)
        UIControlEventTouchDragInside                                   = 1 <<  2,
        UIControlEventTouchDragOutside                                  = 1 <<  3,
        UIControlEventTouchDragEnter                                    = 1 <<  4,
        UIControlEventTouchDragExit                                     = 1 <<  5,
        UIControlEventTouchUpInside                                     = 1 <<  6,
        UIControlEventTouchUpOutside                                    = 1 <<  7,
        UIControlEventTouchCancel                                       = 1 <<  8,
        
        UIControlEventValueChanged                                      = 1 << 12,     // sliders, etc.
        UIControlEventPrimaryActionTriggered NS_ENUM_AVAILABLE_IOS(9_0) = 1 << 13,     // semantic action: for buttons, etc.
        
        UIControlEventEditingDidBegin                                   = 1 << 16,     // UITextField
        UIControlEventEditingChanged                                    = 1 << 17,
        UIControlEventEditingDidEnd                                     = 1 << 18,
        UIControlEventEditingDidEndOnExit                               = 1 << 19,     // 'return key' ending editing
        
        UIControlEventAllTouchEvents                                    = 0x00000FFF,  // for touch events
        UIControlEventAllEditingEvents                                  = 0x000F0000,  // for UITextField
        UIControlEventApplicationReserved                               = 0x0F000000,  // range available for application use
        UIControlEventSystemReserved                                    = 0xF0000000,  // range reserved for internal framework use
        UIControlEventAllEvents                                         = 0xFFFFFFFF   // 相當于上邊的所有值的 或
    };

UIControlEvents的具體解釋

UIControlEventTouchDown
官方：A touch-down event in the control.
解釋：觸下control 中的事件(這個可以用于監測剛剛按下按鈕或者是UISlider的時候的事件)
UIControlEventTouchDownRepeat
官方：A repeated touch-down event in the control; for this event the value of the UITouch tapCount method is greater than one.
解釋：在control上重復地按下的事件這個事件的tap數量大于1
UIControlEventTouchDragInside
官方： An event where a finger is dragged inside the bounds of the control.
解釋：手指在control的bounds范圍內拖動的的事件
UIControlEventTouchDragOutside
官方： An event where a finger is dragged just outside the bounds of the control.
解釋：當手指拖動剛好在control的bounds 范圍外的事件
UIControlEventTouchDragEnter
官方：An event where a finger is dragged into the bounds of the control.
解釋：當手指拖動進入control范圍內的事件
UIControlEventTouchDragExit
官方： An event where a finger is dragged from within a control to outside its bounds.
解釋：當手指從control范圍內到它的bounds外的時候的事件
UIControlEventTouchUpInside
官方：A touch-up event in the control where the finger is inside the bounds of the control.
解釋：手指在在control內部觸發的touch-up事件(經常給按鈕添加這個事件)
UIControlEventTouchUpOutside
官方：A touch-up event in the control where the finger is outside the bounds of the control.
解釋：手指在在control外部觸發的touch-up事件
UIControlEventTouchCancel
官方： A system event canceling the current touches for the control.
解釋：一種系統事件取消control當前觸摸的事件
UIControlEventValueChanged
官方：A touch dragging or otherwise manipulating a control, causing it to emit a series of different values.
解釋：拖動觸摸或其他操作一個control引起這個control顯示一系列不同的值(像UISlider在拖動的時候值的變化可以通過這個事件來監測)
UIControlEventPrimaryActionTriggered
官方： A semantic action triggered by buttons.
解釋：按鈕觸發的語義動作? 這個沒用過
UIControlEventEditingDidBegin
官方：A touch initiating an editing session in a UITextField object by entering its bounds.
解釋：當觸摸UITextField對象后通過進入它的bounds 初始化一個編輯會話
UIControlEventEditingChanged
官方：A touch making an editing change in a UITextField object.
解釋：觸摸UITextField對象后一個編輯改變
UIControlEventEditingDidEnd
官方：A touch ending an editing session in a UITextField object by leaving its bounds.
解釋：在手指離開TextFiled對象的bounds的時候觸摸結束的一個編輯會話
UIControlEventEditingDidEndOnExit
官方：A touch ending an editing session in a UITextField object.
解釋：在UITextField對象中觸摸結束編輯會話
UIControlEventAllTouchEvents
官方：All touch events.
解釋：所有的觸摸事件
UIControlEventAllEditingEvents
官方：All editing touches for UITextField objects.
解釋：對于UITextFiled對象的所有的的編輯觸摸
UIControlEventApplicationReserved
官方：A range of control-event values available for application use.
解釋：為應用使用的預留的一系列可用的的control-event值
UIControlEventSystemReserved
官方：A range of control-event values reserved for internal framework use.
解釋：為內部framework預留的一系列control-event values
UIControlEventAllEvents
官方：All events, including system events.
解釋：所有的事件包括系統事件

Demo研究：

思路：設計了5個按鈕用不同方式添加事件處理（控制變量法）

第一個Button：創建按鈕添加事件，并且添加事件處理，點擊按鈕后方法正常執行;
第二個Button：控制 target 為nil，點擊按鈕后方法正常執行，在響應鏈上找一個對象響應消息;
第三個Button：控制 action 為null 或者是方法寫錯名字會崩潰 unrecognized selector sent to instance 0x7fef757063e0';
第四個Button：給按鈕添加事件 UIControlEventAllEvents；
第五個Button：復位按鈕當前功能是設置 kDisplaceStep = 0;

Demo通過遍歷UIControlEvents 位移枚舉，找出按鈕添加了那些方法。

編譯器Demo截圖：

相關代碼

#import "QiButton_UIControlEventsViewController.h"

static NSUInteger kDisplaceStep = 0;    //!< 偏移位數
static long long const kDisplacementBase = 0x01;   //!< 偏移基數

@implementation QiButton_UIControlEventsViewController {
    
    NSDictionary *_controlEventDictionary;  //!< UIControlEvents 枚舉字典
}

- (void)viewDidLoad {

    [super viewDidLoad];
    
    self.title = @"UIControlEvents";
    self.view.backgroundColor = [UIColor whiteColor];
    
    [self prepareData];
    
    [self controlEventsDemo];
}

#pragma mark - private functions

- (void)prepareData {
    
    _controlEventDictionary = @{
                              @(UIControlEventTouchDown) : @"UIControlEventTouchDown",
                              @(UIControlEventTouchDownRepeat) : @"UIControlEventTouchDownRepeat",
                              @(UIControlEventTouchDragInside) : @"UIControlEventTouchDragInside",
                              @(UIControlEventTouchDragOutside) : @"UIControlEventTouchDragOutside",
                              @(UIControlEventTouchDragEnter) : @"UIControlEventTouchDragEnter",
                              @(UIControlEventTouchDragExit) : @"UIControlEventTouchDragExit",
                              @(UIControlEventTouchUpInside) : @"UIControlEventTouchUpInside",
                              @(UIControlEventTouchUpOutside) : @"UIControlEventTouchUpOutside",
                              @(UIControlEventTouchCancel) : @"UIControlEventTouchCancel",
                              @(UIControlEventValueChanged) : @"UIControlEventValueChanged",
                              @(UIControlEventPrimaryActionTriggered) : @"UIControlEventPrimaryActionTriggered",
                              @(UIControlEventEditingDidBegin):@"UIControlEventEditingDidBegin",
                              @(UIControlEventEditingChanged) : @"UIControlEventEditingChanged",
                              @(UIControlEventEditingDidEnd):@"UIControlEventEditingDidEnd",
                              @(UIControlEventEditingDidEndOnExit):@"UIControlEventEditingDidEndOnExit",
                              @(UIControlEventAllTouchEvents):@"UIControlEventAllTouchEvents",
                              @(UIControlEventAllEditingEvents):@"UIControlEventAllEditingEvents",
                              @(UIControlEventApplicationReserved):@"UIControlEventApplicationReserved",
                              @(UIControlEventSystemReserved):@"UIControlEventSystemReserved",
                              @(UIControlEventAllEvents):@"UIControlEventAllEvents",
                              };
}

- (void)controlEventsDemo {
    
    // - (void)addTarget:(id)target action:(SEL)action forControlEvents:(UIControlEvents)controlEvents;
    /**
     * Demo思路 創建5個按鈕 并且添加事件處理
        * 1. 中規中矩創建按鈕添加事件 并且添加事件處理 點擊按鈕后 方法正常執行
        * 2. target 設置為nil 點擊按鈕后方法正常執行 在響應鏈上找一個對象響應消息
        * 3. action 設置為null 或者是 方法寫錯名字 會崩潰 unrecognized selector sent to instance 0x7fef757063e0'
        * 4. 給按鈕添加 事件 UIControlEventAllEvents
        * 5. 復位按鈕 當前功能是設置 kDisplaceStep = 0;
        查看效果：
        * 6. 讀者可以試著改變UIControlEvents 位移枚舉 輸出為按鈕添加的UIControlEvents的內容
        * 其中還有別的內容像 UITextField 像 UISlider 中的一些事件處理
     */
    self.edgesForExtendedLayout = UIRectEdgeNone;
    CGFloat screenH = [UIScreen mainScreen].bounds.size.height;
    CGFloat screenW = [UIScreen mainScreen].bounds.size.width;
    if (screenH == 812.0 && screenW == 375.0) {
        screenH -= 122.0;
    }else {
        screenH -= 64.0;
    }
    CGFloat btnTopMargin = 20.0;
    CGFloat btnW = [UIScreen mainScreen].bounds.size.width;
    CGFloat btnH = (screenH - (btnTopMargin * 5)) / 5;
    
    UIButton *normalBtn = [[UIButton alloc] initWithFrame:CGRectMake(.0, btnTopMargin, btnW, btnH)];
    [self.view addSubview:normalBtn];
    [normalBtn setTitle:@"normalButton" forState:UIControlStateNormal];
    normalBtn.backgroundColor = [UIColor lightGrayColor];
    [normalBtn addTarget:self action:@selector(normalButtonClicked:) forControlEvents:UIControlEventTouchDown];
    [normalBtn addTarget:self action:@selector(normalButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
    
    UIButton *targetNilBtn = [[UIButton alloc] initWithFrame:CGRectMake(.0, (btnTopMargin * 2 + btnH), btnW, btnH)];
    [self.view addSubview:targetNilBtn];
    [targetNilBtn setTitle:@"targetNilButton" forState:UIControlStateNormal];
    targetNilBtn.backgroundColor = [UIColor grayColor];
    [targetNilBtn addTarget:nil action:@selector(targetNilButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
    [targetNilBtn addTarget:nil action:@selector(targetNilButtonClicked:) forControlEvents:UIControlEventTouchDown];
    
    UIButton *selectorNullBtn = [[UIButton alloc] initWithFrame:CGRectMake(.0, (btnTopMargin * 3 + btnH * 2), btnW, btnH)];
    [self.view addSubview:selectorNullBtn];
    [selectorNullBtn setTitle:@"null Selector Button" forState:UIControlStateNormal];
    selectorNullBtn.backgroundColor = [UIColor darkGrayColor];
    [selectorNullBtn addTarget:self action:@selector(null) forControlEvents:UIControlEventTouchUpInside];
    
    UIButton *allEventsBtn = [[UIButton alloc] initWithFrame:CGRectMake(.0, (btnTopMargin * 4 + btnH * 3), btnW, btnH)];
    [self.view addSubview:allEventsBtn];
    [allEventsBtn setTitle:@"allEventsButton" forState:UIControlStateNormal];
    allEventsBtn.backgroundColor = [[UIColor darkTextColor] colorWithAlphaComponent:0.6];
    [allEventsBtn addTarget:self action:@selector(allEventButtonClicked:) forControlEvents:UIControlEventAllEvents];
    
    UIButton *resetBtn = [[UIButton alloc] initWithFrame:CGRectMake(.0, (btnTopMargin * 5 + btnH * 4), btnW, btnH)];
    [self.view addSubview:resetBtn];
    [resetBtn setTitle:@"復位" forState:UIControlStateNormal];
    resetBtn.backgroundColor = [[UIColor darkTextColor] colorWithAlphaComponent:0.8];
    [resetBtn addTarget:self action:@selector(resetButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
}


#pragma mark - action functions

- (void)normalButtonClicked:(UIButton *)sender {
    
    UIControlEvents tempEvents = sender.allControlEvents;
    
    for (; kDisplaceStep < 32; ++ kDisplaceStep) {
        if (tempEvents & (kDisplacementBase << kDisplaceStep)) {
            NSLog(@"添加的allControlEvents:%lu",(unsigned long)sender.allControlEvents);
            NSLog(@"分別為: %llu--%@", (kDisplacementBase << kDisplaceStep),_controlEventDictionary[@(kDisplacementBase << kDisplaceStep)]); // %o %x
            // 65 相當于 UIControlEventTouchDown | UIControlEventTouchUpInside
        }
    }
    NSLog(@"%s",__FUNCTION__);
}

- (void)targetNilButtonClicked:(UIButton *)sender {
    
    NSLog(@"添加的allControlEvents:%lu",(unsigned long)sender.allControlEvents);
    NSLog(@"%s",__FUNCTION__);
    // 調用次數為2 是因為測試的UIControlEventTouchDown 和 UIControlEventTouchUpInside 各調用了一次
}

- (void)allEventButtonClicked:(UIButton *)sender {
    
    UIControlEvents tempEvents = sender.allControlEvents;
    for (; kDisplaceStep < 32; ++ kDisplaceStep) {
        if (tempEvents & (kDisplacementBase << kDisplaceStep)) {
            NSLog(@"添加的allControlEvents:%lu",(unsigned long)sender.allControlEvents);
            NSLog(@"可能有: %llu--%@", (kDisplacementBase << kDisplaceStep),_controlEventDictionary[@(kDisplacementBase << kDisplaceStep)]); // %o %x
        }
    }
    // 其輸出結果代表其可以響應很多事件，這種情況下就不能夠準確的確定是那個事件了， 因為可能是彼此之間二進制位重復的值 做的 或 操作后的結果。
    NSLog(@"%s",__FUNCTION__);
}

- (void)resetButtonClicked:(UIButton *)sender {
    
    NSLog(@"%s",__FUNCTION__);
    kDisplaceStep = 0;
}

@end

代碼GitHub地址

特別致謝：

蘋果關于UIControlEvents的官方文檔

三个男躁一个女,国精产品一区一手机的秘密,麦子交换系列最经典十句话,欧美国产综合欧美视频

iOS UIButton之UIControlEvents介紹

iOS UIButton之UIControlEvents介紹

UIControlEvents 相關位移枚舉

UIControlEvents的具體解釋

Demo研究：

思路：設計了5個按鈕用不同方式添加事件處理（控制變量法）

特別致謝：

三个男躁一个女,国精产品一区一手机的秘密,麦子交换系列最经典十句话,欧美 国产 综合 欧美 视频

iOS UIButton之UIControlEvents介紹

UIControlEvents 相關位移枚舉

UIControlEvents的具體解釋

Demo研究：

思路： 設計了5個按鈕 用不同方式添加事件處理（控制變量法）

特別致謝：

三个男躁一个女,国精产品一区一手机的秘密,麦子交换系列最经典十句话,欧美国产综合欧美视频

思路：設計了5個按鈕用不同方式添加事件處理（控制變量法）