iOS学习——（转）UIResponder详解
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2022-07-08 18:34:13
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 Co ......
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 <Foundation/Foundation.h>
5 #import <UIKit/UIKitDefines.h>
6 #import <UIKit/UIEvent.h>
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 <NSObject>
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 <UIResponderStandardEditActions>
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<UITouch *> *)touches withEvent:(nullable UIEvent *)event;
88 /** 手指移动时响应 */
89 - (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event;
90 /** 手指抬起时响应 */
91 - (void)touchesEnded:(NSSet<UITouch *> *)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<UITouch *> *)touches withEvent:(nullable UIEvent *)event;
94 /** 3DTouch响应(iOS9.1后使用) */
95 - (void)touchesEstimatedPropertiesUpdated:(NSSet<UITouch *> *)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<UIPress *> *)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<UIPress *> *)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<UIPress *> *)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<UIPress *> *)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 <NSCopying, NSSecureCoding>
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<UIKeyCommand *> *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<UITouch *> *)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<UITouch *> *)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<UITouch *> *)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<UITouch *> *)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：
- 启动接受远程事件：[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
- 设置成为第一响应者（UIViewController，AppDelegate中不需要设置）
- 获取音频的控制权
// ZMAudioView.m
#import "ZMAudioView.h"
#import <AVFoundation/AVFoundation.h>
@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：
- 启用用户交互：self.userInteractionEnabled = YES;
- 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）
- 返回菜单需要显示的按钮，并重写实现对应方法
- 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：
- 在调用方法时需要添加注册一个对应的撤销方法
- 撤销/ 重做只需要调用undoManager中的相应方法即可
- 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 <UIKit/UIKit.h>
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<ZMLineModel *> *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<UITouch *> *)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<UITouch *> *)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：
- 设置对象成为第一响应者（UIViewController，AppDelegate中不需要设置）
- 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<UIKeyCommand *> *)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
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