iOS UIPasteboard

一、简介

1.创建

UIPasteboard 是 iOS 中访问粘贴板的原生控件，可分为系统等级的和 APP 等级的，系统等级的独立于 APP，可以复制一个 APP 的内容到另一个 APP ；APP 等级的只能在 APP 内进行复制和粘贴。

    //系统级
    UIPasteboard * pasteboard = [UIPasteboard generalPasteboard];
    [pasteboard setString:@"系统"];
    NSLog(@"%@",pasteboard.string);
    
    //APP级
    UIPasteboard * pasteboard1 = [UIPasteboard pasteboardWithName:@"test" create:YES];
    [pasteboard1 setString:@"app"];
    NSLog(@"%@",pasteboard1.string);
}

2.数据类型

可以复制在粘贴板的数据类型有 NSString、UIImage、NSURL、UIColor、NSData 以及由这些类型元素组成的数组。可分别由它们的 set 方法将数据放在粘贴板中。

3.常用的方法

/*通过名称获取粘贴板并且移除*/
+ (void)removePasteboardWithName:(NSString *)pasteboardName; 
/*从粘贴板中获取数据，pasteboardType是自定义的，说明app可以处理哪种类型的数据*/
- (nullable NSData *)dataForPasteboardType:(NSString *)pasteboardType; 
/*data类型的数据放在粘贴板中，pasteboardType同上*/
- (void)setData:(NSData *)data forPasteboardType:(NSString *)pasteboardType;
/*从粘贴板中取出data*/
- (nullable NSData *)dataForPasteboardType:(NSString *)pasteboardType;

4.使用方法

在 iOS 中，支持 UIPasteboard 原生控件只有 UITextField 、UITextView、UIWebView 这三个，如果想自定义一个控件能够使用 UIPasteboard，需要在定义的时候重载 -(BOOL)canBecomeFirstResponder 和-(BOOL)canPerformAction:(SEL)action withSender:(id)sender 这两个方法，前者设置控件可称为第一响应器，后者决定这个控件能够使用复制、剪切、选中、全选、粘贴等的哪一种或几种功能，并重载对应的 -(void)copy:(id)sender、-(void)cut:(id)sender、-(void)select:(id)sender、-(void)selectAll:(id)sender、-(void)paste:(id)sender 方法，在这几个方法中处理事件，UIMenuController 负责显示 UI。

二、示例

DJCopyView

#import <UIKit/UIKit.h>

@interface DJCopyView : UIView

@end

#import "DJCopyView.h"
@interface DJCopyView()

@property ( nonatomic,strong) UILabel *label1;
@property ( nonatomic,strong) UILabel *label2;

@end

@implementation DJCopyView

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        self.backgroundColor = [UIColor orangeColor];
        self.label1 = [[UILabel alloc]initWithFrame:CGRectMake(15, 10, frame.size.width - 30, 30)];
        self.label1.text = @"texttext";
        self.label1.backgroundColor = [UIColor blueColor];
        [self addSubview:self.label1];
        
        self.label2 = [[UILabel alloc]initWithFrame:CGRectMake(15, 50, frame.size.width - 30, 30)];
        [self addSubview:self.label2];
        self.label2.backgroundColor = [UIColor blueColor];
    }
    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 setString:self.label1.text];
}

-(void)paste:(id)sender{
    UIPasteboard* pasteboard = [UIPasteboard generalPasteboard];
    self.label2.text = [pasteboard string];
}

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    [self becomeFirstResponder];
    UIMenuController* menuController = [UIMenuController sharedMenuController];
    [menuController showMenuFromView:self rect:self.label1.frame];
}

@end