将导航栏的后退按钮中的文字去掉一直是老大难问题,现在可以使用运行时机制,将后退按钮文字清空
创建UINavigationItem的category,直接上代码
.h文件
#import <UIKit/UIKit.h> @interface UINavigationItem (CustomBackButton) @end
.m文件
#import "UINavigationItem+CustomBackButton.h"
#import <objc/runtime.h>
@implementation UINavigationItem (CustomBackButton)
+(void)load{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Method originalMethodImp = class_getInstanceMethod(self, @selector(backBarButtonItem));
Method destMethodImp = class_getInstanceMethod(self, @selector(myCustomBackButton_backBarbuttonItem));
method_exchangeImplementations(originalMethodImp, destMethodImp);
});
}
-(UIBarButtonItem *)backBarButtonItem{
return [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStyleBordered target:nil action:NULL];
}
static char kCustomBackButtonKey;
-(UIBarButtonItem *)myCustomBackButton_backBarbuttonItem{
UIBarButtonItem *item = [self myCustomBackButton_backBarbuttonItem];
if (item) {
return item;
}
item = objc_getAssociatedObject(self, &kCustomBackButtonKey);
if (!item) {
item = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStyleBordered target:nil action:NULL];
objc_setAssociatedObject(self, &kCustomBackButtonKey, item, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
return item;
}
- (void)dealloc {
objc_removeAssociatedObjects(self);
}
@end
注意
#import <objc/runtime.h>
然后在Appdelegate中导入即可
#import "UINavigationItem+CustomBackButton.h"
原文链接:http://blog.csdn.net/zhangao0086/article/details/22432387