iOS开发之-UIMenuController

在iOS应用中,我们经常会做一些跟输入内容相关的操作,由于对绝大多数用户来说打字都是一件比较痛苦的事情,因此有没有一种可以让我们的用户以偷懒的方式完成内容的输入呢???

非常幸运的是,apple给我们提供了这种偷懒的功能,让用户可以通过"command+c","command+v"的方式来完成内容的输入,完成这种偷懒功能的主角就是UIMenuController.

Paste_Image.png

在iOS的控件中,如下的控件已经默认支持UIMenuViewController:
1.UITextFild

Paste_Image.png

2.UITextView

Paste_Image.png

3.UIWebView...

Paste_Image.png

这么好用的功能只有这三个控件能玩儿么?? 我们自定义的控件可以实现这样的功能么??
经研究发现,答案是YES的,现在我将以UILabel为例子进行说明

要使用UIMenuController指向某一个控件,就必须让该控件成为第一响应者
1.让该控件成为第一响应者

[self becomeFirstResponder];

2.注意:并不是调用了上面一句代码的所有控件都能成为第一响应者
因此我们还得在这个控件中添加:

- (BOOL)canBecomeFirstResponder
{  
    return YES;
}

3.控制菜单上显示什么样的菜单项

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
    if (action == @selector(copy:) || action == @selector(paste:) || action == @selector(cut:)) {
        return YES;
    }
    return NO;
}

4.让菜单显示出来

[menuVc setTargetRect:self.frame inView:self.superview];
[menuVc setMenuVisible:YES animated:YES];

5.处理菜单上菜单项的点击事件

- (void)copy:(UIMenuController *)menu
{
    UIPasteboard *board = [UIPasteboard generalPasteboard];
    board.string = self.text;
    
}

- (void)paste:(UIMenuController *)menu
{
    UIPasteboard *board = [UIPasteboard generalPasteboard];
    self.text = board.string;;
}

- (void)cut:(UIMenuController *)menu
{
    [self copy:menu];
    self.text = nil;
}

Paste_Image.png

#import "LXBLabel.h"

@implementation LXBLabel

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self setup];
    }
    return self;
}

- (void)awakeFromNib
{
    [self setup];
}

- (void)setup
{
    self.userInteractionEnabled = YES;
    [self addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(clickLabel)]];
}

- (void)clickLabel
{   
    [self becomeFirstResponder];
    UIMenuController *menuVc = [UIMenuController sharedMenuController];

// 控制好menu的显示与隐藏
UIMenuController *menuVc = [UIMenuController sharedMenuController];
    if (menuVc.isMenuVisible) {
        [menuVc setMenuVisible:NO animated:YES];
    }
    [menuVc setTargetRect:self.frame inView:self.superview];
    [menuVc setMenuVisible:YES animated:YES];
}

- (BOOL)canBecomeFirstResponder
{
   // 明确该控件可以成为第一响应者 
    return YES;
}

// 该控件可以执行哪些动作
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
    if (action == @selector(copy:) || action == @selector(paste:) || action == @selector(cut:)) {
        return YES;
    }
    return NO;
}

- (void)copy:(UIMenuController *)menu
{
    UIPasteboard *board = [UIPasteboard generalPasteboard];
    board.string = self.text;
    
}

- (void)paste:(UIMenuController *)menu
{
    UIPasteboard *board = [UIPasteboard generalPasteboard];
    self.text = board.string;;
}

- (void)cut:(UIMenuController *)menu
{
    [self copy:menu];
    self.text = nil;
}

@end

在实际的开发中,系统默认的菜单项就够了吗??
肯定是不够的,我们往往要根据项目的实际需求去定制菜单项,比如:

Paste_Image.png

定制菜单项:

 UIMenuItem *item1 = [[UIMenuItem alloc] initWithTitle:@"item1" action:@selector(item1Click:)];
 UIMenuItem *item2 = [[UIMenuItem alloc] initWithTitle:@"item2" action:@selector(item2Click:)];
 menuVc.menuItems = @[item1,item2];

// 处理菜单项的点击事件
- (void)item1Click:(UIMenuController *)menu
{
    NSLog(@"item1Click");
}

- (void)item2Click:(UIMenuController *)menu
{
    NSLog(@"item2Click");
}