使用iOS7自定义UIBarButtonItem对齐

Question

所以我遇到了许多其他人在使用UIButton作为自定义视图创建UIBarButtonItem时遇到的相同问题.

基本上,按钮向左或向右约10像素到远.当我使用没有自定义视图的常规BarButtonItem时,这不会发生.

这篇文章提供了部分解决方案: UIBarButton With Custom View

这是我通过子类化UIButton创建的代码(如另一篇文章中所述)

    - (UIEdgeInsets)alignmentRectInsets {
    UIEdgeInsets insets;
    if ([self isLeftButton]) {
        insets = UIEdgeInsetsMake(0, 9.0f, 0, 0);
    }
    else { // IF ITS A RIGHT BUTTON
        insets = UIEdgeInsetsMake(0, 0, 0, 9.0f);
    }
    return insets;
}


- (BOOL)isLeftButton {
    return self.frame.origin.x < (self.superview.frame.size.width / 2);
}

这很好用,但当我从导航控制器弹出一个视图控制器回到这个主视图时,按钮仍然错误地定位了大约.3秒,然后它捕捉到正确的插图.

这是一个巨大的眼睛,我不知道如何阻止它像这样攫取.有什么想法吗？谢谢!

Answer 1

我和你以及其他许多人一样有同样的问题.经过很长一段时间试图解决它,最后我做到了.这是您必须包含在*-Prefix.pch文件中的类别.就这样!

UINavigationItem + iOS7Spacing.h

#import <Foundation/Foundation.h>
@interface UINavigationItem (iOS7Spacing)
@end

UINavigationItem + iOS7Spacing.m

#import "UINavigationItem+iOS7Spacing.h"
#import <objc/runtime.h>

@implementation UINavigationItem (iOS7Spacing)

- (BOOL)isIOS7
{
    return ([[[UIDevice currentDevice] systemVersion] compare:@"7" options:NSNumericSearch] != NSOrderedAscending);
}

- (UIBarButtonItem *)spacer
{
    UIBarButtonItem *space = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
    space.width = -11;
    return space;
}

- (void)mk_setLeftBarButtonItem:(UIBarButtonItem *)leftBarButtonItem
{
    if ([self isIOS7] && leftBarButtonItem) {
        [self mk_setLeftBarButtonItem:nil];
        [self mk_setLeftBarButtonItems:@[[self spacer], leftBarButtonItem]];
    } else {
        [self mk_setLeftBarButtonItem:leftBarButtonItem];
    }
}

- (void)mk_setLeftBarButtonItems:(NSArray *)leftBarButtonItems
{
    if ([self isIOS7] && leftBarButtonItems && leftBarButtonItems.count > 0) {

        NSMutableArray *items = [[NSMutableArray alloc] initWithCapacity:leftBarButtonItems.count + 1];
        [items addObject:[self spacer]];
        [items addObjectsFromArray:leftBarButtonItems];

        [self mk_setLeftBarButtonItems:items];
    } else {
        [self mk_setLeftBarButtonItems:leftBarButtonItems];
    }
}

- (void)mk_setRightBarButtonItem:(UIBarButtonItem *)rightBarButtonItem
{
    if ([self isIOS7] && rightBarButtonItem) {
        [self mk_setRightBarButtonItem:nil];
        [self mk_setRightBarButtonItems:@[[self spacer], rightBarButtonItem]];
    } else {
        [self mk_setRightBarButtonItem:rightBarButtonItem];
    }
}

- (void)mk_setRightBarButtonItems:(NSArray *)rightBarButtonItems
{
    if ([self isIOS7] && rightBarButtonItems && rightBarButtonItems.count > 0) {

        NSMutableArray *items = [[NSMutableArray alloc] initWithCapacity:rightBarButtonItems.count + 1];
        [items addObject:[self spacer]];
        [items addObjectsFromArray:rightBarButtonItems];

        [self mk_setRightBarButtonItems:items];
    } else {
        [self mk_setRightBarButtonItems:rightBarButtonItems];
    }
}

+ (void)mk_swizzle:(SEL)aSelector
{
    SEL bSelector = NSSelectorFromString([NSString stringWithFormat:@"mk_%@", NSStringFromSelector(aSelector)]);

    Method m1 = class_getInstanceMethod(self, aSelector);
    Method m2 = class_getInstanceMethod(self, bSelector);

    method_exchangeImplementations(m1, m2);
}

+ (void)load
{
    [self mk_swizzle:@selector(setLeftBarButtonItem:)];
    [self mk_swizzle:@selector(setLeftBarButtonItems:)];
    [self mk_swizzle:@selector(setRightBarButtonItem:)];
    [self mk_swizzle:@selector(setRightBarButtonItems:)];
}

@end

GitHub上的UINavigationItem + iOS7Spacing类别