需求描述:
在项目开发过程中,遇到一种情况,需要自定义uibarbuttonitem,来实现分享样式,并在ipad中弹出系统分享框(uiactivityviewcontroller),系统分享框需要指定显示位置(barbuttonitem)。而自定义的uibarbuttonitem target指向的是uibutton。这与需求不符,需自定义uibarbuttonitem。
在介绍自定义uibarbuttonitem前,先介绍一下相关控件的子父类关系(也可以说继承关系)。
1、uibaritem
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ns_class_available_ios(2_0) @interface uibaritem : nsobject <nscoding, uiappearance>
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2、uibarbuttonitem
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ns_class_available_ios(2_0) @interface uibarbuttonitem : uibaritem <nscoding>
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3、uitabbaritem
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ns_class_available_ios(2_0) @interface uitabbaritem : uibaritem
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下面是在界面上的显示效果
uibarbuttonitem和uitabbaritem效果显示
从上图中看到uibarbuttonitem有三种效果显示,分别是
1、导航左侧返回按钮,uinavigationitem中的backbarbuttonitem属性
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@property(nullable,nonatomic,strong) uibarbuttonitem *backbarbuttonitem
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2、纯文本的uibarbuttonitem
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- (instancetype)initwithtitle:(nullable nsstring *)title style:(uibarbuttonitemstyle)style target:(nullable id)target action:(nullable sel)action;
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3、纯图片的uibarbuttonitem,其中包括自定义图片和系统样式
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- (instancetype)initwithimage:(nullable uiimage *)image style:(uibarbuttonitemstyle)style target:(nullable id)target action:(nullable sel)action;
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- (instancetype)initwithbarbuttonsystemitem:(uibarbuttonsystemitem)systemitem target:(nullable id)target action:(nullable sel)action;
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uitoolbar使用uibarbuttonitem与导航效果一致。
关于uitabbaritem在这里就不多介绍,只是拿其显示效果与uibarbuttonitem对比。
在开发过程中,我们会使用到自定义uibarbuttonitem,来显示我们想要的界面效果。使用的方法常为:
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- (instancetype)initwithcustomview:(uiview *)customview;
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- ( void )viewdidload {
[super viewdidload];
//自定义view
uiview *view = [[uiview alloc] initwithframe:cgrectmake(0.0, 0.0, 60.0, 40.0)];
view.backgroundcolor = [uicolor redcolor];
//自定义按钮
uibutton *btn = [uibutton buttonwithtype:uibuttontypecustom];
btn.frame = view.bounds;
[btn addtarget:self action:@selector(clickright:) forcontrolevents:uicontroleventtouchupinside];
[view addsubview:btn];
//自定义item
uibarbuttonitem *baritem = [[uibarbuttonitem alloc] initwithcustomview:view];
//
self.navigationitem.leftbarbuttonitem = baritem;
}
#pragma mark -
- ( void )clickright:(id)sender {
nslog(@ "sender:%@" ,sender);
}
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其中打印sender,其类型是uibutton。
2017-10-17 16:08:43.917 testimage[5482:163865] sender:<uibutton: 0x7fb9bad12e60; frame = (0 0; 60 40); opaque = no; layer = <calayer: 0x61000003b940>>
通过上面描述,发现系统方法不能实现项目需求效果。当然也可以通过属性保存uibarbuttonitem方法来实现需求效果。即在点击按钮响应后,直接使用保存的uibarbuttonitem,但是我没有采用这种方法。
下面是我给出的两种解决方案:
方案一
继承uibarbuttonitem,实现子类。
定义子类
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#import <uikit/uikit.h>
@interface llbarbuttonitem : uibarbuttonitem
@end
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#import "llbarbuttonitem.h"
@implementation llbarbuttonitem
- (id)initwithcustomview:(uiview *)customview {
self = [super initwithcustomview:customview];
if (self) {
uibutton *btn = [uibutton buttonwithtype:uibuttontypecustom];
btn.frame = customview.bounds;
btn.backgroundcolor = [uicolor clearcolor];
[btn addtarget:self action:@selector(clickbutton:) forcontrolevents:uicontroleventtouchupinside];
[customview addsubview:btn];
}
return self;
}
- ( void )clickbutton:(uibutton *)sender {
if (self.target && [self.target respondstoselector:self.action]) {
//[self.target performselector:self.action withobject:self];
imp imp = [self.target methodforselector:self.action];
void (*func)(id, sel, id) = ( void *)imp;
func(self.target, self.action, self);
}
}
@end
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定义子类对象,调用子类对象
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- ( void )viewdidload {
[super viewdidload];
//自定义view
uiview *view = [[uiview alloc] initwithframe:cgrectmake(0.0, 0.0, 60.0, 40.0)];
view.backgroundcolor = [uicolor clearcolor];
//自定义item
llbarbuttonitem *baritem = [[llbarbuttonitem alloc] initwithcustomview:view];
baritem.target = self;
baritem.action = @selector(clickright:);
//
self.navigationitem.leftbarbuttonitem = baritem;
}
#pragma mark -
- ( void )clickright:(id)sender {
nslog(@ "sender:%@" ,sender);
}
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打印target对象
2017-10-17 16:24:11.696 testimage[5557:170144] sender:<llbarbuttonitem: 0x7fb403c16080>
方案二
uibarbuttonitem类别
定义类别
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#import <uikit/uikit.h>
@interface uibarbuttonitem (custom)
- ( void )addcutomtarget:(id)target action:(sel)action;
@end
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#import "uibarbuttonitem+custom.h"
@implementation uibarbuttonitem (custom)
- ( void )addcutomtarget:(id)target action:(sel)action {
if (self.customview != nil) {
self.target = target;
self.action = action;
//
uibutton *btn = [uibutton buttonwithtype:uibuttontypecustom];
btn.frame = self.customview.bounds;
btn.backgroundcolor = [uicolor clearcolor];
[btn addtarget:self action:@selector(clickbutton:) forcontrolevents:uicontroleventtouchupinside];
[self.customview addsubview:btn];
}
}
- ( void )clickbutton:(uibutton *)sender {
if (self.target && [self.target respondstoselector:self.action]) {
//[self.target performselector:self.action withobject:self];
imp imp = [self.target methodforselector:self.action];
void (*func)(id, sel, id) = ( void *)imp;
func(self.target, self.action, self);
}
}
@end
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调用类别方法
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- ( void )viewdidload {
[super viewdidload];
//自定义view
uiview *view = [[uiview alloc] initwithframe:cgrectmake(0.0, 0.0, 60.0, 40.0)];
view.backgroundcolor = [uicolor clearcolor];
//自定义item
uibarbuttonitem *baritem = [[uibarbuttonitem alloc] initwithcustomview:view];
[baritem addcutomtarget:self action:@selector(clickright:)];
//
self.navigationitem.leftbarbuttonitem = baritem;
}
#pragma mark -
- ( void )clickright:(id)sender {
nslog(@ "sender:%@" ,sender);
}
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打印target对象
2017-10-17 16:28:14.407 testimage[5598:172418] sender:<uibarbuttonitem: 0x7ffeda609e20>
两种方法都使用了imp做消息传递。
你更喜欢哪一种?!
总结
以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作具有一定的参考学习价值,如果有疑问大家可以留言交流,谢谢大家对服务器之家的支持。
原文链接:https://www.jianshu.com/p/7869e2b126e9