iOS学习——（转）UIResponder详解

本文转载自：ios开发 之 UIResponder详解　

　　我们知道UIResponder是所有视图View的基类，在iOS中UIResponder类是专门用来响应用户的操作处理各种事件的，包括触摸事件(Touch Events)、运动事件(Motion Events)、远程控制事件(Remote Control Events)。我们知道UIApplication、UIView、UIViewController这几个类是直接继承自UIResponder,所以这些类都可以响应事件。当然我们自定义的继承自UIView的View以及自定义的继承自UIViewController的控制器都可以响应事件。本文将详细介绍UIResponder类。

一 UIResponder.h文件注释版

　　首先，我们对UIResponder.h文件进行了研究和解释，并对各模块进行了注释添加，方便我们在阅读和学习时候的理解。在学习了UIView、NSObject的.h文件之后，我们发现这些基类的.h文件的组织架构基本类似，最初是定义该类中需要用到的一些枚举类型数据，然后对相应的协议进行定义，接着就是对本类进行定义，一些基本的属性和方法的定义，最后就是对本类做各种功能性的分类。

  1 //
  2 //  UIResponder.h
  3 
  4 #import 
  5 #import 
  6 #import 
  7 
  8 NS_ASSUME_NONNULL_BEGIN
  9 
 10 @class UIPress;
 11 @class UIPressesEvent;
 12 
 13 #pragma mark - UIResponderStandardEditActions协议定义
 14 
 15 @protocol UIResponderStandardEditActions 
 16 @optional
 17 /** 剪切事件 */
 18 - (void)cut:(nullable id)sender NS_AVAILABLE_IOS(3_0);
 19 /** 复制事件 */
 20 - (void)copy:(nullable id)sender NS_AVAILABLE_IOS(3_0);
 21 /** 粘贴事件 */
 22 - (void)paste:(nullable id)sender NS_AVAILABLE_IOS(3_0);
 23 /** 选择事件 */
 24 - (void)select:(nullable id)sender NS_AVAILABLE_IOS(3_0);
 25 /** 全选事件 */
 26 - (void)selectAll:(nullable id)sender NS_AVAILABLE_IOS(3_0);
 27 /** 删除事件 */
 28 - (void)delete:(nullable id)sender NS_AVAILABLE_IOS(3_2);
 29 /** 从左到右写入字符串(居左) */
 30 - (void)makeTextWritingDirectionLeftToRight:(nullable id)sender NS_AVAILABLE_IOS(5_0);
 31 /** 从右到左写入字符串(居右) */
 32 - (void)makeTextWritingDirectionRightToLeft:(nullable id)sender NS_AVAILABLE_IOS(5_0);
 33 /** 切换字体为黑体(粗体) */
 34 - (void)toggleBoldface:(nullable id)sender NS_AVAILABLE_IOS(6_0);
 35 /** 切换字体为斜体 */
 36 - (void)toggleItalics:(nullable id)sender NS_AVAILABLE_IOS(6_0);
 37 /** 给文字添加下划线 */
 38 - (void)toggleUnderline:(nullable id)sender NS_AVAILABLE_IOS(6_0);
 39 
 40 /** 增加字体大小 */
 41 - (void)increaseSize:(nullable id)sender NS_AVAILABLE_IOS(7_0);
 42 /** 减小字体大小 */
 43 - (void)decreaseSize:(nullable id)sender NS_AVAILABLE_IOS(7_0);
 44 
 45 @end
 46 
 47 #pragma mark - UIResponder类定义
 48 
 49 NS_CLASS_AVAILABLE_IOS(2_0) @interface UIResponder : NSObject 
 50 
 51 #pragma mark - 响应者相关方法
 52 
 53 /** 获取下一个响应者 */
 54 #if UIKIT_DEFINE_AS_PROPERTIES
 55 @property(nonatomic, readonly, nullable) UIResponder *nextResponder;
 56 #else
 57 - (nullable UIResponder *)nextResponder;
 58 #endif
 59 
 60 /** 是否允许成为第一响应者。默认返回NO */
 61 #if UIKIT_DEFINE_AS_PROPERTIES
 62 @property(nonatomic, readonly) BOOL canBecomeFirstResponder;
 63 #else
 64 - (BOOL)canBecomeFirstResponder;
 65 #endif
 66 /** 设置成为第一响应者 */
 67 - (BOOL)becomeFirstResponder;
 68 
 69 /** 是否允许放弃第一响应者。默认返回YES */
 70 #if UIKIT_DEFINE_AS_PROPERTIES
 71 @property(nonatomic, readonly) BOOL canResignFirstResponder;
 72 #else
 73 - (BOOL)canResignFirstResponder;
 74 #endif
 75 /** 设置放弃第一响应者 */
 76 - (BOOL)resignFirstResponder;
 77 
 78 /** 判断对象是否是第一响应者 */
 79 #if UIKIT_DEFINE_AS_PROPERTIES
 80 @property(nonatomic, readonly) BOOL isFirstResponder;
 81 #else
 82 - (BOOL)isFirstResponder;
 83 #endif
 84 
 85 #pragma mark - 触摸相关方法，一般用于响应屏幕触摸
 86 /** 手指按下时响应 */
 87 - (void)touchesBegan:(NSSet *)touches withEvent:(nullable UIEvent *)event;
 88 /** 手指移动时响应 */
 89 - (void)touchesMoved:(NSSet *)touches withEvent:(nullable UIEvent *)event;
 90 /** 手指抬起时响应 */
 91 - (void)touchesEnded:(NSSet *)touches withEvent:(nullable UIEvent *)event;
 92 /** 取消(意外中断, 如:电话, 系统警告窗等) */
 93 - (void)touchesCancelled:(NSSet *)touches withEvent:(nullable UIEvent *)event;
 94 /** 3DTouch响应(iOS9.1后使用) */
 95 - (void)touchesEstimatedPropertiesUpdated:(NSSet *)touches NS_AVAILABLE_IOS(9_1);
 96 
 97 #pragma mark - 深按相关方法，一般用于遥控器按键响应
 98 /** 手指按压开始时响应 */
 99 - (void)pressesBegan:(NSSet *)presses withEvent:(nullable UIPressesEvent *)event NS_AVAILABLE_IOS(9_0);
100 /** 手指按压位置移动时响应 */
101 - (void)pressesChanged:(NSSet *)presses withEvent:(nullable UIPressesEvent *)event NS_AVAILABLE_IOS(9_0);
102 /** 手指抬起接受按压时响应 */
103 - (void)pressesEnded:(NSSet *)presses withEvent:(nullable UIPressesEvent *)event NS_AVAILABLE_IOS(9_0);
104 /** 按压取消(意外中断, 如:电话, 系统警告窗等) */
105 - (void)pressesCancelled:(NSSet *)presses withEvent:(nullable UIPressesEvent *)event NS_AVAILABLE_IOS(9_0);
106 
107 #pragma mark - 加速相关方法，一般用于摇一摇、运动事件监听等
108 /** 开始加速 */
109 - (void)motionBegan:(UIEventSubtype)motion withEvent:(nullable UIEvent *)event NS_AVAILABLE_IOS(3_0);
110 /** 结束加速 */
111 - (void)motionEnded:(UIEventSubtype)motion withEvent:(nullable UIEvent *)event NS_AVAILABLE_IOS(3_0);
112 /** 加速取消（意外中断, 如:电话, 系统警告窗等） */
113 - (void)motionCancelled:(UIEventSubtype)motion withEvent:(nullable UIEvent *)event NS_AVAILABLE_IOS(3_0);
114 
115 /** 远程控制事件 */
116 - (void)remoteControlReceivedWithEvent:(nullable UIEvent *)event NS_AVAILABLE_IOS(4_0);
117 
118 /** 返回UIMenuController需要显示的控件(如：复制，粘贴等) */
119 - (BOOL)canPerformAction:(SEL)action withSender:(nullable id)sender NS_AVAILABLE_IOS(3_0);
120 
121 /** 返回响应的操作目标对象 */
122 - (nullable id)targetForAction:(SEL)action withSender:(nullable id)sender NS_AVAILABLE_IOS(7_0);
123 
124 /** 获取响应链就近共享撤消管理 */
125 @property(nullable, nonatomic,readonly) NSUndoManager *undoManager NS_AVAILABLE_IOS(3_0);
126 
127 @end
128 
129 /** 快捷主键枚举 */
130 typedef NS_OPTIONS(NSInteger, UIKeyModifierFlags) {
131     UIKeyModifierAlphaShift     = 1 << 16,  //!< Alpha+Shift键.
132     UIKeyModifierShift          = 1 << 17,  //!< Shift键.
133     UIKeyModifierControl        = 1 << 18,  //!< Control键.
134     UIKeyModifierAlternate      = 1 << 19,  //!< Alt键.
135     UIKeyModifierCommand        = 1 << 20,  //!< Command键.
136     UIKeyModifierNumericPad     = 1 << 21,  //!< Num键.
137 } NS_ENUM_AVAILABLE_IOS(7_0);
138 
139 #pragma mark - 快捷键对象
140 
141 NS_CLASS_AVAILABLE_IOS(7_0) @interface UIKeyCommand : NSObject 
142 
143 /** 初始化对象 */
144 - (instancetype)init NS_DESIGNATED_INITIALIZER;
145 /** 初始化对象 */
146 - (nullable instancetype)initWithCoder:(NSCoder *)aDecoder NS_DESIGNATED_INITIALIZER;
147 
148 /** 获取快捷辅键（如快捷命令【Command+A】中的 A 键） */
149 @property (nonatomic,readonly) NSString *input;
150 /** 获取快捷主键（如快捷命令【Command+A】中的 Command 键） */
151 @property (nonatomic,readonly) UIKeyModifierFlags modifierFlags;
152 /** 显示给用户的快捷键标题 */
153 @property (nullable,nonatomic,copy) NSString *discoverabilityTitle NS_AVAILABLE_IOS(9_0);
154 
155 /** 创建一个快捷键命令 */
156 + (UIKeyCommand *)keyCommandWithInput:(NSString *)input modifierFlags:(UIKeyModifierFlags)modifierFlags action:(SEL)action;
157 
158 /** 创建一个快捷键命令 */
159 + (UIKeyCommand *)keyCommandWithInput:(NSString *)input modifierFlags:(UIKeyModifierFlags)modifierFlags action:(SEL)action discoverabilityTitle:(NSString *)discoverabilityTitle NS_AVAILABLE_IOS(9_0);
160 
161 @end
162 
163 #pragma mark - 响应快捷命令
164 
165 @interface UIResponder (UIResponderKeyCommands)
166 /** 返回快捷键命令数组 */
167 @property (nullable,nonatomic,readonly) NSArray *keyCommands NS_AVAILABLE_IOS(7_0);
168 @end
169 
170 @class UIInputViewController;
171 @class UITextInputMode;
172 @class UITextInputAssistantItem;
173 
174 #pragma mark - 输入视图
175 
176 @interface UIResponder (UIResponderInputViewAdditions)
177 
178 /** 键盘输入视图(系统默认的,可以自定义) */
179 @property (nullable, nonatomic, readonly, strong) __kindof UIView *inputView NS_AVAILABLE_IOS(3_2);
180 /** 弹出键盘时附带的视图 */
181 @property (nullable, nonatomic, readonly, strong) __kindof UIView *inputAccessoryView NS_AVAILABLE_IOS(3_2);
182 
183 /** 输入助手配置键盘的快捷方式栏时使用 */
184 @property (nonnull, nonatomic, readonly, strong) UITextInputAssistantItem *inputAssistantItem NS_AVAILABLE_IOS(9_0) __TVOS_PROHIBITED __WATCHOS_PROHIBITED;
185 
186 /** 键盘输入视图控制器 */
187 @property (nullable, nonatomic, readonly, strong) UIInputViewController *inputViewController NS_AVAILABLE_IOS(8_0);
188 /** 弹出键盘时附带的视图的视图控制器 */
189 @property (nullable, nonatomic, readonly, strong) UIInputViewController *inputAccessoryViewController NS_AVAILABLE_IOS(8_0);
190 
191 /** 文本输入模式 */
192 @property (nullable, nonatomic, readonly, strong) UITextInputMode *textInputMode NS_AVAILABLE_IOS(7_0);
193 
194 /** 文本输入模式标识 */
195 @property (nullable, nonatomic, readonly, strong) NSString *textInputContextIdentifier NS_AVAILABLE_IOS(7_0);
196 /** 根据设置的标识清除指定的文本输入模式 */
197 + (void)clearTextInputContextIdentifier:(NSString *)identifier NS_AVAILABLE_IOS(7_0);
198 
199 /** 重新刷新键盘输入视图 */
200 - (void)reloadInputViews NS_AVAILABLE_IOS(3_2);
201 
202 @end
203 
204 /** 特殊快捷辅键定义 */
205 UIKIT_EXTERN NSString *const UIKeyInputUpArrow         NS_AVAILABLE_IOS(7_0); //!< 上按键.
206 UIKIT_EXTERN NSString *const UIKeyInputDownArrow       NS_AVAILABLE_IOS(7_0); //!< 下按键.
207 UIKIT_EXTERN NSString *const UIKeyInputLeftArrow       NS_AVAILABLE_IOS(7_0); //!< 左按键.
208 UIKIT_EXTERN NSString *const UIKeyInputRightArrow      NS_AVAILABLE_IOS(7_0); //!< 右按键
209 UIKIT_EXTERN NSString *const UIKeyInputEscape          NS_AVAILABLE_IOS(7_0); //!< Esc按键.
210 
211 #pragma mark - 响应者活动
212 
213 @interface UIResponder (ActivityContinuation)
214 /** 用户活动 */
215 @property (nullable, nonatomic, strong) NSUserActivity *userActivity NS_AVAILABLE_IOS(8_0);
216 /** 更新用户活动 */
217 - (void)updateUserActivityState:(NSUserActivity *)activity NS_AVAILABLE_IOS(8_0);
218 /** 恢复用户活动 */
219 - (void)restoreUserActivityState:(NSUserActivity *)activity NS_AVAILABLE_IOS(8_0);
220 @end
221 
222 NS_ASSUME_NONNULL_END

 二 UIResponder的使用

2.1 通过响应者链查找视图的视图控制器

 　　通过响应链查找视图控制器，nextResponder获取下一个响应者，响应者顺序为：

 

/**
 *  查找视图的视图控制器
 *
 *  @param view 视图
 *
 *  @return 返回视图的控制器
 */
- (UIViewController *)getControllerFromView:(UIView *)view {
    // 遍历响应者链。返回第一个找到视图控制器
    UIResponder *responder = view;
    while ((responder = [responder nextResponder])){
        if ([responder isKindOfClass: [UIViewController class]]){
            return (UIViewController *)responder;
        }
    }
    // 如果没有找到则返回nil
    return nil;
}

2.2 设置与取消第一响应者

　　UIView默认不允许设置为第一响应者，因此设置UIView为第一响应者需要重写canBecomeFirstResponder方法并返回YES。 设置为第一响应者后，对象则可以接受远程控制事件进行处理（如耳机线控）。UITextField、UITextView成为第一响应者后会弹出输入键盘，取消第一响应者则会隐藏输入键盘。 

 1 //  ZMFirstResponderView.m
 2 
 3 #import "ZMFirstResponderView.h"
 4 
 5 @implementation ZMFirstResponderView
 6 
 7 /** 演示设置为第一响应者 */
 8 - (void)setBecomeFirstResponder {
 9     // 判断对象是否已经是第一响应者
10     if ([self isFirstResponder]) {
11         return;
12     }
13     // 判断对象是否允许成为第一响应者
14     if ([self canBecomeFirstResponder]) {
15         // 设置成为第一响应者
16         [self becomeFirstResponder];
17     }
18 }
19 
20 /** 演示放弃第一响应者 */
21 - (void)setResignFirstResponder {
22     // 判断对象是否不是第一响应者
23     if (![self isFirstResponder]) {
24         return;
25     }
26     // 判断对象是否允许放弃第一响应者
27     if ([self canResignFirstResponder]) {
28         // 设置放弃第一响应者
29         [self resignFirstResponder];
30     }
31 }
32 
33 /** 重写方法，允许对象成为第一响应者 */
34 - (BOOL)canBecomeFirstResponder {
35     return YES;
36 }
37 
38 @end

2.3 触摸相关方法，一般用于响应屏幕触摸

/** 手指按下时响应 */
- (void)touchesBegan:(NSSet *)touches withEvent:(nullable UIEvent *)event {
    [super touchesBegan:touches withEvent:event];
    NSLog(@"--->手指按下时响应");
}

/** 手指移动时响应 */
- (void)touchesMoved:(NSSet *)touches withEvent:(nullable UIEvent *)event {
    [super touchesMoved:touches withEvent:event];
    NSLog(@"--->手指移动时响应");
}

/** 手指抬起时响应 */
- (void)touchesEnded:(NSSet *)touches withEvent:(nullable UIEvent *)event {
    [super touchesEnded:touches withEvent:event];
    NSLog(@"--->手指抬起时响应");
}

/** 触摸取消(意外中断, 如:电话, Home键退出等) */
- (void)touchesCancelled:(NSSet *)touches withEvent:(nullable UIEvent *)event {
    [super touchesCancelled:touches withEvent:event];
    NSLog(@"--->取消触摸响应");
}

2.4 加速相关方法，一般用于摇一摇、运动事件监听等

/** 开始加速 */
- (void)motionBegan:(UIEventSubtype)motion withEvent:(nullable UIEvent *)event NS_AVAILABLE_IOS(3_0) {
    [super motionBegan:motion withEvent:event];
    NSLog(@"--->开始加速");
}

/** 结束加速 */
- (void)motionEnded:(UIEventSubtype)motion withEvent:(nullable UIEvent *)event NS_AVAILABLE_IOS(3_0) {
    [super motionEnded:motion withEvent:event];
    NSLog(@"--->结束加速");
}

/** 加速取消（意外中断, 如:电话, Home键退出等） */
- (void)motionCancelled:(UIEventSubtype)motion withEvent:(nullable UIEvent *)event NS_AVAILABLE_IOS(3_0) {
    [super motionCancelled:motion withEvent:event];
    NSLog(@"--->加速取消");
}

2.5 远程控制方法，一般用于耳机线控

耳机线控要注意三点要素：

1. 启动接受远程事件：[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
2. 设置成为第一响应者（UIViewController，AppDelegate中不需要设置）
3. 获取音频的控制权

//  ZMAudioView.m

#import "ZMAudioView.h"
#import 

@implementation ZMAudioView

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // 1 启动接受远程事件
        [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
        //2  设置成为第一响应者
        [self becomeFirstResponder];
        // 3 播放一段静音文件，使APP获取音频的控制权
        NSURL *audioURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"mute_60s" ofType:@"mp3"]];
        AVAudioPlayer *audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:audioURL error:nil];
        [audioPlayer play];
    }
    return self;
}

/** 允许对象成为第一响应者 */
- (BOOL)canBecomeFirstResponder {
    return YES;
}

/** 远程控制事件响应 */
- (void)remoteControlReceivedWithEvent:(UIEvent *)receivedEvent {
    NSLog(@"--->耳机线控响应");
}

- (void)dealloc {
    // 停止接受远程事件
    [[UIApplication sharedApplication] endReceivingRemoteControlEvents];
    // 放弃第一响应者
    [self resignFirstResponder];
}

@end

2.6 在UILabel中实现长按菜单（复制、粘贴等）

为UILabel添加长按菜单需要注意几点：

1. 启用用户交互：self.userInteractionEnabled = YES;
2. 在显示菜单之前设置对象成为第一响应者（UIViewController，AppDelegate中不需要设置）
3. 返回菜单需要显示的按钮，并重写实现对应方法
4. 注册长按手势，显示菜单

//  ZMMenuLabel.m

#import "ZMMenuLabel.h"

@implementation ZMMenuLabel

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // 启用用户交互
        self.userInteractionEnabled = YES;
        // 添加长按手势
        UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressMenu:)];
        longPressGesture.minimumPressDuration = 0.2;
        [self addGestureRecognizer:longPressGesture];
    }
    return self;
}

/** 允许对象成为第一响应者 */
- (BOOL)canBecomeFirstResponder {
    return YES;
}

/** 长按响应 */
- (void)longPressMenu:(UILongPressGestureRecognizer *)sender {
    if (sender.state == UIGestureRecognizerStateBegan) {
        // 设置成为第一响应者
        [self becomeFirstResponder];
        // 显示菜单
        UIMenuController *menuCtrl = [UIMenuController sharedMenuController];
        [menuCtrl setTargetRect:self.frame inView:self.superview];
        [menuCtrl setMenuVisible:YES animated:YES];
    }
}

/** 返回需要显示的菜单按钮 */
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    // 只显示复制、粘贴按钮
    if (action == @selector(copy:) || action == @selector(paste:)) {
        return YES;
    }
    return NO;
}

/** 实现复制方法 */
- (void)copy:(id)sender {
    UIPasteboard *paste = [UIPasteboard generalPasteboard];
    paste.string = self.text;
}

/** 实现粘贴方法 */
- (void)paste:(id)sender {
    UIPasteboard *paste = [UIPasteboard generalPasteboard];
    self.text = paste.string;
}

@end

2.7 使用NSUndoManager实现画板撤销/重做功能

实现撤销/重做注意以下几点：

1. 在调用方法时需要添加注册一个对应的撤销方法
2. 撤销/ 重做只需要调用undoManager中的相应方法即可
3. 如果需要多个动作一起撤销则需要标记分组

  1 /** ==============ZMDrawingBoardView.h文件=================== */
  2 
  3 #import 
  4 
  5 /** 画板View */
  6 @interface ZMDrawingBoardView : UIView
  7 
  8 @end
  9 
 10 
 11 /** 划线Model */
 12 @interface ZMLineModel : NSObject
 13 
 14 @property (nonatomic) CGPoint begin;
 15 @property (nonatomic) CGPoint end;
 16 
 17 @end
 18 
 19 
 20 /** ==============ZMDrawingBoardView.m文件=================== */
 21 
 22 #import "ZMDrawingBoardView.h"
 23 
 24 /** 画板View */
 25 @interface ZMDrawingBoardView ()
 26 
 27 @property (nonatomic, strong) ZMLineModel *currentLine;
 28 @property (nonatomic, strong) NSMutableArray *toucheArray;
 29 
 30 @end
 31 
 32 @implementation ZMDrawingBoardView
 33 
 34 
 35 - (instancetype)initWithFrame:(CGRect)frame
 36 {
 37     self = [super initWithFrame:frame];
 38     if (self) {
 39         [self initSubView];
 40         self.backgroundColor = [UIColor whiteColor];
 41         self.toucheArray = [NSMutableArray array];
 42     }
 43     return self;
 44 }
 45 
 46 /** 绘制画板 */
 47 - (void)drawRect:(CGRect)rect {
 48     // 获得上下文
 49     CGContextRef context = UIGraphicsGetCurrentContext();
 50     // 设置样式
 51     CGContextSetLineCap(context, kCGLineCapSquare);
 52     // 设置宽度
 53     CGContextSetLineWidth(context, 5.0);
 54     // 设置颜色
 55     CGContextSetStrokeColorWithColor(context, [[UIColor redColor] CGColor]);
 56     
 57     for (ZMLineModel *line in self.toucheArray) {
 58         // 开始绘制
 59         CGContextBeginPath(context);
 60         // 移动画笔到起点
 61         CGContextMoveToPoint(context, line.begin.x, line.begin.y);
 62         // 添加下一点
 63         CGContextAddLineToPoint(context, line.end.x, line.end.y);
 64         // 绘制完成
 65         CGContextStrokePath(context);
 66     }
 67 }
 68 
 69 /** 划线开始 */
 70 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
 71 {
 72     // 标记开始撤销分组
 73     [self.undoManager beginUndoGrouping];
 74     
 75     for (UITouch *touch in touches) {
 76         // 记录起始点
 77         CGPoint locTouch = [touch locationInView:self];
 78         _currentLine = [[ZMLineModel alloc] init];
 79         _currentLine.begin = locTouch;
 80         _currentLine.end = locTouch;
 81     }
 82     
 83 }
 84 
 85 /** 划线移动 */
 86 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
 87 {
 88     for (UITouch *touch in touches) {
 89         // 添加线条
 90         CGPoint locTouch = [touch locationInView:self];
 91         _currentLine.end = locTouch;
 92         [self addLine:_currentLine];
 93         // 当前线条
 94         _currentLine = [[ZMLineModel alloc] init];
 95         _currentLine.begin = locTouch;
 96         _currentLine.end = locTouch;
 97     }
 98 }
 99 
100 /** 划线结束 */
101 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
102 {
103     // 结束标记撤销分组
104     [self.undoManager endUndoGrouping];
105 }
106 
107 /** 添加划线 */
108 - (void)addLine:(ZMLineModel *)line
109 {
110     // 添加划线并重绘画板
111     [self.toucheArray addObject:line];
112     [self setNeedsDisplay];
113     // 注册撤销方法
114     [[self.undoManager prepareWithInvocationTarget:self] removeLine:line];
115 }
116 
117 /** 移除划线 */
118 - (void)removeLine:(ZMLineModel *)line
119 {
120     if ([self.toucheArray containsObject:line]) {
121         // 移除划线并重绘画板
122         [self.toucheArray removeObject:line];
123         [self setNeedsDisplay];
124         // 注册撤销方法
125         [[self.undoManager prepareWithInvocationTarget:self] addLine:line];
126     }
127 }
128 
129 /** 撤销按钮点击响应 */
130 - (void)undoButtonAction:(id)sender {
131     if ([self.undoManager canUndo]) {
132         [self.undoManager undo];
133     }
134 }
135 
136 /** 重做按钮点击响应 */
137 - (void)redoButtonAction:(id)sender {
138     if ([self.undoManager canRedo]) {
139         [self.undoManager redo];
140     }
141 }
142 
143 /** 初始化子控件 */
144 - (void)initSubView {
145     // 撤销按钮
146     UIButton *undoButton = [UIButton buttonWithType:UIButtonTypeSystem];
147     undoButton.frame = CGRectMake(0, 64, 70, 50);
148     [undoButton setTitle:@"undo撤销" forState:UIControlStateNormal];
149     [undoButton sizeToFit];
150     [undoButton addTarget:self action:@selector(undoButtonAction:) forControlEvents:UIControlEventTouchUpInside];
151     [self addSubview:undoButton];
152     // 重做按钮
153     UIButton *redoButton = [UIButton buttonWithType:UIButtonTypeSystem];
154     redoButton.frame = CGRectMake(CGRectGetWidth(self.frame)-70, 64, 70, 50);
155     [redoButton setTitle:@"redo重做" forState:UIControlStateNormal];
156     [redoButton sizeToFit];
157     [redoButton addTarget:self action:@selector(redoButtonAction:) forControlEvents:UIControlEventTouchUpInside];
158     [self addSubview:redoButton];
159 }
160 
161 @end

2.8 自定义快捷键

自定义快捷键需要注意两点：

1. 设置对象成为第一响应者（UIViewController，AppDelegate中不需要设置）
2. 重写keyCommands返回快捷命令组合

//  ZMKeyCommandView.m

#import "ZMKeyCommandView.h"

@implementation ZMKeyCommandView

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // 设置成为第一响应者
        [self becomeFirstResponder];
    }
    return self;
}

/** 允许对象成为第一响应者 */
- (BOOL)canBecomeFirstResponder {
    return YES;
}

/** 返回快捷命令数组 */
-(NSArray *)keyCommands {
    return @[
             [UIKeyCommand keyCommandWithInput:UIKeyInputEscape modifierFlags:UIKeyModifierShift action:@selector(pressedShiftAndEscapeKey:) discoverabilityTitle:@"自定义[Shift+Esc]快捷键"],
             [UIKeyCommand keyCommandWithInput:@"a" modifierFlags:UIKeyModifierShift action:@selector(pressedShiftAndAKey:) discoverabilityTitle:@"自定义[Shift+A]快捷键"]
             ];
}

/** Shift+Esc快捷命令响应 */
-(void)pressedShiftAndEscapeKey:(UIKeyCommand *)keyCommand {
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:keyCommand.discoverabilityTitle message:[NSString stringWithFormat:@"按下快捷辅键:[%@]", keyCommand.input] delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil];
    [alertView show];
}

/** Shift+A快捷命令响应 */
-(void)pressedShiftAndAKey:(UIKeyCommand *)keyCommand {
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:keyCommand.discoverabilityTitle message:[NSString stringWithFormat:@"按下快捷辅键:[%@]", keyCommand.input] delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil];
    [alertView show];
}

@end

2.9 自定义UITextField输入键盘

 1 //  ZMCustomInputView.m
 2 
 3 #import "ZMCustomInputView.h"
 4 
 5 #define MAIN_SCREEN_WIDTH [[UIScreen mainScreen] bounds].size.width   //!< 屏幕的Width
 6 
 7 @interface ZMCustomInputView ()
 8 
 9 @property (nonatomic, strong) UITextField *textField;
10 @property (nonatomic, strong) UIView *customInputView;
11 @property (nonatomic, strong) UIToolbar *customAccessoryView;
12 
13 @end
14 
15 @implementation ZMCustomInputView
16 
17 - (instancetype)initWithFrame:(CGRect)frame
18 {
19     self = [super initWithFrame:frame];
20     if (self) {
21         // 添加TextField
22         [self addSubview:self.textField];
23     }
24     return self;
25 }
26 
27 /** 懒加载textField */
28 - (UITextField *)textField {
29     if (!_textField) {
30         // 初始化textField
31         _textField = [[UITextField alloc]initWithFrame:CGRectMake(50, 100, MAIN_SCREEN_WIDTH - 100, 30)];
32         _textField.borderStyle = UITextBorderStyleRoundedRect;
33         _textField.placeholder = @"测试";
34         // 设置自定义键盘View
35         _textField.inputView = self.customInputView;
36         _textField.inputAccessoryView = self.customAccessoryView;
37     }
38     return _textField;
39 }
40 
41 /** 懒加载customInputView */
42 - (UIView *)customInputView {
43     if (!_customInputView) {
44         _customInputView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, MAIN_SCREEN_WIDTH, 220)];
45         _customInputView.backgroundColor = [UIColor lightGrayColor];
46         UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0, 100, MAIN_SCREEN_WIDTH, 40)];
47         label.textAlignment = NSTextAlignmentCenter;
48         label.text = @"自定义inputView";
49         [_customInputView addSubview:label];
50     }
51     return _customInputView;
52 }
53 
54 /** 懒加载customAccessoryView */
55 - (UIToolbar *)customAccessoryView {
56     if (!_customAccessoryView) {
57         _customAccessoryView = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, MAIN_SCREEN_WIDTH, 40)];
58         _customAccessoryView.barTintColor = [UIColor orangeColor];
59         UIBarButtonItem *space = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
60         UIBarButtonItem *done = [[UIBarButtonItem alloc]initWithTitle:@"完成" style:UIBarButtonItemStyleDone target:self action:@selector(done)];
61         [_customAccessoryView setItems:@[space, space, done]];
62     }
63     return _customAccessoryView;
64 }
65 
66 /** 响应完成按钮 */
67 - (void)done {
68     [self.textField resignFirstResponder];
69 }
70 
71 
72 @end

 

  

转载于:https://www.cnblogs.com/mukekeheart/p/8462314.html