更改默认条形高度时，自定义UINavigationBar项目位置不正确

Question

我将UINavigationBar子类化，并根据设备更改其高度。一切都很完美，直到我添加按钮。如果默认高度发生变化，按钮不会位于中央，而是位于底部。

RevUINavigationBar.m：

#import "RevUINavigationBar.h"
#import "Utils.h"

#define MAIN_COLOR_COMPONENTS       { 0, 0, 0, 1.0, 0, 0, 0, 1.0 }
#define LIGHT_COLOR_COMPONENTS      { 0.263, 0.263, 0.263, 1.0, 0.263, 0.263, 0.263, 1.0 }

@implementation RevUINavigationBar

- (id)initWithFrame:(CGRect)frame
{
     self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
     return self;
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // emulate the tint colored bar
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGFloat locations[2] = { 0.0, 1.0 };
    CGColorSpaceRef myColorspace = CGColorSpaceCreateDeviceRGB();

    CGFloat topComponents[8] = MAIN_COLOR_COMPONENTS;
    CGGradientRef topGradient = CGGradientCreateWithColorComponents(myColorspace, topComponents, locations, 2);
    CGContextDrawLinearGradient(context, topGradient, CGPointMake(0, 0), CGPointMake(0, self.frame.size.height/2), 0);
    CGGradientRelease(topGradient);

    CGFloat botComponents[8] = LIGHT_COLOR_COMPONENTS;
    CGGradientRef botGradient = CGGradientCreateWithColorComponents(myColorspace, botComponents, locations, 2);
    CGContextDrawLinearGradient(context, botGradient,
                            CGPointMake(0, self.frame.size.height/2), CGPointMake(0, self.frame.size.height), 0);
    CGGradientRelease(botGradient);

    CGColorSpaceRelease(myColorspace);    

    // top Line
    CGContextSetRGBStrokeColor(context, 0, 0, 0, 1.0);
    CGContextMoveToPoint(context, 0, 0);
    CGContextAddLineToPoint(context, self.frame.size.width, 0);
    CGContextStrokePath(context);

    // bottom line
    CGContextSetRGBStrokeColor(context, 0, 0, 0, 1.0);
    CGContextMoveToPoint(context, 0, self.frame.size.height);
    CGContextAddLineToPoint(context, self.frame.size.width, self.frame.size.height);
    CGContextStrokePath(context);
}

- (CGSize)sizeThatFits:(CGSize)size
{
    int navigationBarHeight = 44;

    if ([Utils isIpad] == YES)
        navigationBarHeight = 88;

    return CGSizeMake(self.frame.size.width, navigationBarHeight);
}
@end

添加按钮：

- (void)showCustomNavBarItems
{
    NSMutableArray *leftItems = [NSMutableArray new];
    if (self != [[self.navigationController viewControllers] objectAtIndex:0])
    {
        UIImage *backBtnImg = [UIImage imageNamedSmart:@"BackB"];
        UIButton *backBtn = [UIButton buttonWithType:UIButtonTypeCustom];
        [backBtn addTarget:self action:@selector(backBarButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
        [backBtn setImage:backBtnImg forState:UIControlStateNormal];
        backBtn.frame = CGRectMake(0, 0, backBtnImg.size.width, backBtnImg.size.height);
        UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithCustomView:backBtn];                                       
        backButton.imageInsets = UIEdgeInsetsMake(0, 0, 0, 0);
        [leftItems addObject:backButton];
    }

    UIImageView *logoView = [[UIImageView alloc]initWithImage:[UIImage imageNamedSmart:@"Logo"]];
    UIBarButtonItem *logo = [[UIBarButtonItem alloc] initWithCustomView:logoView];

    [leftItems addObject:logo];    

    self.navigationItem.leftBarButtonItems = leftItems;
    [self.navigationController.navigationBar layoutSubviews];
}

Answer 1

解决方案是覆盖函数layoutSubViews并将我的所有控件设置到正确的位置：

- (void)layoutSubviews
{
    [super layoutSubviews];
    for (UIView *view in self.subviews)
        view.frame = CGRectMake(view.frame.origin.x,
                                self.frame.size.width / 2 - view.frame.size.width / 2,
                                view.frame.size.width,
                                view.frame.size.height);
}