實(shí)現(xiàn)攔截UIViewController的pop操作有兩種方式：
- 自定義實(shí)現(xiàn)返回按鈕，即設(shè)置
UIBarButtonItem來(lái)實(shí)現(xiàn)自定義的返回操作。 - 創(chuàng)建
UINavigatonController的Category，來(lái)定制navigationBar: shouldPopItem:的邏輯。
UIViewController+BackButtonHandler.h：
#import <UIKit/UIKit.h>
@protocol BackButtonHandlerProtocol <NSObject>
@optional
// Override this method in UIViewController derived class to handle 'Back' button click
-(BOOL)navigationShouldPopOnBackButton;
@end
@interface UIViewController (BackButtonHandler) <BackButtonHandlerProtocol>
@end
UIViewController+BackButtonHandler.m：
#import "UIViewController+BackButtonHandler.h"
@implementation UIViewController (BackButtonHandler)
@end
@implementation UINavigationController (ShouldPopOnBackButton)
- (BOOL)navigationBar:(UINavigationBar *)navigationBar shouldPopItem:(UINavigationItem *)item {
if([self.viewControllers count] < [navigationBar.items count]) {
return YES;
}
BOOL shouldPop = YES;
UIViewController* vc = [self topViewController];
if([vc respondsToSelector:@selector(navigationShouldPopOnBackButton)]) {
shouldPop = [vc navigationShouldPopOnBackButton];
}
if(shouldPop) {
dispatch_async(dispatch_get_main_queue(), ^{
[self popViewControllerAnimated:YES];
});
} else {
// Workaround for iOS7.1. Thanks to @boliva - http://stackoverflow.com/posts/comments/34452906
for(UIView *subview in [navigationBar subviews]) {
if(0. < subview.alpha && subview.alpha < 1.) {
[UIView animateWithDuration:.25 animations:^{
subview.alpha = 1.;
}];
}
}
}
return NO;
}
使用：
- 在
UIViewController當(dāng)中引入頭文件
#import "UIViewController+BackButtonHandler.h"
- 在
UIViewController中實(shí)現(xiàn)navigationShouldPopOnBackButton方法。
- (BOOL)navigationShouldPopOnBackButton{
[[[UIAlertView alloc] initWithTitle:@"提示" message:@"確定返回上一界面?"
delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"確定", nil] show];
//renturn no 攔截pop事件
return NO;
}
參考：
