一、自帶剪切板操作的原生UI控件
在iOS的UI系統(tǒng)中,有3個控件自帶剪切板操作,分別是UITextField、UITextView與UIWebView。在這些控件的文字交互處進行長按手勢可以在屏幕視圖上喚出系統(tǒng)的剪切板控件,用戶可以進行復(fù)制、粘貼,剪切等操作
二、系統(tǒng)的剪切板管理類UIPasteboard
實際上,當(dāng)用戶通過上面的空間進行復(fù)制、剪切等操作時,被選中的內(nèi)容會被存放到系統(tǒng)的剪切板中,并且這個剪切板并不只能存放字符串?dāng)?shù)據(jù),其還可以進行圖片數(shù)據(jù)與網(wǎng)址URL數(shù)據(jù)的存放。這個剪切板就是UIPasteboard類,開發(fā)者也可以直接通過它來操作數(shù)據(jù)進行應(yīng)用內(nèi)或應(yīng)用間傳值。
UIPasteboard類有3個初始化方法,如下:
//獲取系統(tǒng)級別的剪切板
+ (UIPasteboard *)generalPasteboard;
//獲取一個自定義的剪切板 name參數(shù)為此剪切板的名稱 create參數(shù)用于設(shè)置當(dāng)這個剪切板不存在時 是否進行創(chuàng)建
+ (nullable UIPasteboard *)pasteboardWithName:(NSString *)pasteboardName create:(BOOL)create;
//獲取一個應(yīng)用內(nèi)可用的剪切板
+ (UIPasteboard *)pasteboardWithUniqueName;
上面3個初始化方法,分別獲取或創(chuàng)建3個級別不同的剪切板,系統(tǒng)級別的剪切板在整個設(shè)備中共享,即是應(yīng)用程序被刪掉,其向系統(tǒng)級的剪切板中寫入的數(shù)據(jù)依然在。自定義的剪切板通過一個特定的名稱字符串進行創(chuàng)建,它在應(yīng)用程序內(nèi)或者同一開發(fā)者開發(fā)的其他應(yīng)用程序中可以進行數(shù)據(jù)共享。第3個方法創(chuàng)建的剪切板等價為使用第2個方法創(chuàng)建的剪切板,只是其名稱字符串為nil,它通常用于當(dāng)前應(yīng)用內(nèi)部。
注意:使用第3個方法創(chuàng)建的剪切板默認是不進行數(shù)據(jù)持久化的,及當(dāng)應(yīng)用程序退出后,剪切板中內(nèi)容將別抹去。若要實現(xiàn)持久化,需要設(shè)置persistent屬性為YES。
UIPasteboard中常用方法及屬性如下:
//剪切板的名稱
@property(readonly,nonatomic) NSString *name;
//根據(jù)名稱刪除一個剪切板
+ (void)removePasteboardWithName:(NSString *)pasteboardName;
//是否進行持久化
@property(getter=isPersistent,nonatomic) BOOL persistent;
//此剪切板的改變次數(shù) 系統(tǒng)級別的剪切板只有當(dāng)設(shè)備重新啟動時 這個值才會清零
@property(readonly,nonatomic) NSInteger changeCount;
下面這些方法用于設(shè)置與獲取剪切板中的數(shù)據(jù):
最新一組數(shù)據(jù)對象的存取:
/獲取剪切板中最新數(shù)據(jù)的類型
- (NSArray*)pasteboardTypes;
//獲取剪切板中最新數(shù)據(jù)對象是否包含某一類型的數(shù)據(jù)- (BOOL)containsPasteboardTypes:(NSArray*)pasteboardTypes;
//將剪切板中最新數(shù)據(jù)對象某一類型的數(shù)據(jù)取出
- (nullable NSData *)dataForPasteboardType:(NSString *)pasteboardType;
//將剪切板中最新數(shù)據(jù)對象某一類型的值取出
- (nullable id)valueForPasteboardType:(NSString *)pasteboardType;
//為剪切板中最新數(shù)據(jù)對應(yīng)的某一數(shù)據(jù)類型設(shè)置值
- (void)setValue:(id)value forPasteboardType:(NSString *)pasteboardType;
//為剪切板中最新數(shù)據(jù)對應(yīng)的某一數(shù)據(jù)類型設(shè)置數(shù)據(jù)
- (void)setData:(NSData *)data forPasteboardType:(NSString *)pasteboardType;
多組數(shù)據(jù)對象的存?。?/p>
?//數(shù)據(jù)組數(shù)@property(readonly,nonatomic) NSInteger numberOfItems;
//獲取一組數(shù)據(jù)對象包含的數(shù)據(jù)類型
- (nullable NSArray *)pasteboardTypesForItemSet:(nullable NSIndexSet*)itemSet;
//獲取一組數(shù)據(jù)對象中是否包含某些數(shù)據(jù)類型
- (BOOL)containsPasteboardTypes:(NSArray*)pasteboardTypes inItemSet:(nullable NSIndexSet *)itemSet;
//根據(jù)數(shù)據(jù)類型獲取一組數(shù)據(jù)對象
- (nullable NSIndexSet *)itemSetWithPasteboardTypes:(NSArray *)pasteboardTypes;
//根據(jù)數(shù)據(jù)類型獲取一組數(shù)據(jù)的值
- (nullable NSArray *)valuesForPasteboardType:(NSString *)pasteboardType inItemSet:(nullable NSIndexSet *)itemSet;
//根據(jù)數(shù)據(jù)類型獲取一組數(shù)據(jù)的NSData數(shù)據(jù)
- (nullable NSArray *)dataForPasteboardType:(NSString *)pasteboardType inItemSet:(nullable NSIndexSet *)itemSet;
//所有數(shù)據(jù)對象
@property(nonatomic,copy) NSArray *items;
//添加一組數(shù)據(jù)對象
- (void)addItems:(NSArray*> *)items;
上面方法中很多需要傳入數(shù)據(jù)類型參數(shù),這些參數(shù)是系統(tǒng)定義好的一些字符竄,如下:
//所有字符串類型數(shù)據(jù)的類型定義字符串?dāng)?shù)組
UIKIT_EXTERN NSArray*UIPasteboardTypeListString;
//所有URL類型數(shù)據(jù)的類型定義字符串?dāng)?shù)組
UIKIT_EXTERN NSArray*UIPasteboardTypeListURL;
//所有圖片數(shù)據(jù)的類型定義字符串?dāng)?shù)據(jù)
UIKIT_EXTERN NSArray*UIPasteboardTypeListImage;
//所有顏色數(shù)據(jù)的類型定義字符串?dāng)?shù)組
UIKIT_EXTERN NSArray*UIPasteboardTypeListColor;
相比于上面兩組方法,下面這些方法更加面向?qū)ο?,在開發(fā)中使用更加方便與快捷:
//獲取或設(shè)置剪切板中的字符串?dāng)?shù)據(jù)
@property(nullable,nonatomic,copy) NSString *string;
//獲取或設(shè)置剪切板中的字符串?dāng)?shù)組
@property(nullable,nonatomic,copy) NSArray*strings;
//獲取或設(shè)置剪切板中的URL數(shù)據(jù)
@property(nullable,nonatomic,copy) NSURL *URL;
//獲取或設(shè)置剪切板中的URL數(shù)組
@property(nullable,nonatomic,copy) NSArray*URLs;
//獲取或s何止剪切板中的圖片數(shù)據(jù)
@property(nullable,nonatomic,copy) UIImage *image;
//獲取或設(shè)置剪切板中的圖片數(shù)組
@property(nullable,nonatomic,copy) NSArray*images;
//獲取或設(shè)置剪切板中的顏色數(shù)據(jù)
@property(nullable,nonatomic,copy) UIColor *color;
//獲取或設(shè)置剪切板中的顏色數(shù)組
@property(nullable,nonatomic,copy) NSArray*colors;
對剪切板的某些操作會觸發(fā)如下通知:
//剪切板內(nèi)容發(fā)生變化時發(fā)送的通知
UIKIT_EXTERN NSString *const UIPasteboardChangedNotification;
//剪切板數(shù)據(jù)類型鍵值增加時發(fā)送的通知
UIKIT_EXTERN NSString *const UIPasteboardChangedTypesAddedKey;
//剪切板數(shù)據(jù)類型鍵值移除時發(fā)送的通知
UIKIT_EXTERN NSString *const UIPasteboardChangedTypesRemovedKey;
//剪切板被刪除時發(fā)送的通知
UIKIT_EXTERN NSString *const UIPasteboardRemovedNotification;
三、復(fù)制圖片的簡單例子
創(chuàng)建一個CopyView
#import "CopyView.h"
@interface CopyView ()
@property (strong, nonatomic) UIImageView* img1;
@property (strong, nonatomic) UIImageView* img2;
@end?
@implementation CopyView
-(UIImageView *)img1{??
if (_img1 == nil) {? ?
?_img1 = [[UIImageView alloc] initWithFrame:CGRectMake(10.0f, 20.0f, 100.0f, 100.0f)];?
?? NSString* path = [[NSBundle mainBundle] pathForResource:@"NetworldImage" ofType:@"jpg"];
? ? _img1.image = [UIImage imageWithContentsOfFile:path];?
?}??
return _img1;
}?
-(UIImageView *)img2{? if (_img2 == nil) {?
?? _img2 = [[UIImageView alloc] initWithFrame:CGRectMake(CGRectGetMaxX(self.img1.frame)+50.0f, 20.0f, 100.0f, 100.0f)];
? ? _img2.backgroundColor = [UIColor lightGrayColor];?
?}??
return _img2;
}
?- (instancetype)initWithFrame:(CGRect)frame {
? self = [super initWithFrame:frame];
? if (self) {?
?? self.backgroundColor = [UIColor whiteColor];
? ? [self addSubview:self.img1];
? ? [self addSubview:self.img2];
? }??
return self;
}?
-(BOOL)canBecomeFirstResponder{
? return YES;
}
-(BOOL)canPerformAction:(SEL)action withSender:(id)sender{
? NSArray* methodNameArr = @[@"copy:",@"cut:",@"select:",@"selectAll:",@"paste:"];
? if ([methodNameArr containsObject:NSStringFromSelector(action)]) {?
?? return YES;?
?}??
return [super canPerformAction:action withSender:sender];
}?
-(void)copy:(id)sender{?
?UIPasteboard* pasteboard = [UIPasteboard generalPasteboard];
? [pasteboard setImage:self.img1.image];
}
?-(void)paste:(id)sender{?
?UIPasteboard* pasteboard = [UIPasteboard generalPasteboard];
? self.img2.image = [pasteboard image];
}?
-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{
[self becomeFirstResponder];
UIMenuController* menuController = [UIMenuController sharedMenuController];
[menuController setTargetRect:self.img1.frame inView:self];
[menuController setMenuVisible:YES animated:YES];
}
@end
在controller中
#import "ViewController.h"
#import "CopyView.h"
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
CopyView* cv = [[CopyView alloc] initWithFrame:self.view.bounds];
self.view = cv;
}
@end