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.
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在iOS的控件中,如下的控件已经默认支持UIMenuViewController:
1.UITextFild
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2.UITextView
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3.UIWebView...
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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;
}
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#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:
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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");
}
