将带有两个UIBarButtonItem的UIToolbar添加到UINavigationBar:可怜的UIToolbar以及iPhone 4怎么样

Question

我正在跟随这里的第二个提示.在这篇技巧文章中,两个UIBarButtonItems放在UIToolbar中.最后,UIToolbar被添加到UINavigationBar中.现在我的问题:

1)UIToolbar顶部有一条白线.如果我增加UIToolbar的大小,则渐变是错误的.我在UIToolbar上使用以下大小:

    UIToolbar *toolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 90, 44.01)];

我该怎样摆脱白线？看这里:

问题是存在白色而不是灰色线.如果它是灰色的,一切都会很完美.

2)iPhone 3和iPhone 4的显示尺寸有何不同？我是否必须检查使用哪个iPhone然后加倍？

编辑:

这些按钮的创建方式类似于我从上述网站获取的以下示例:

// create a toolbar to have two buttons in the right
UIToolbar* tools = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 133, 44.01)];

// create the array to hold the buttons, which then gets added to the toolbar
NSMutableArray* buttons = [[NSMutableArray alloc] initWithCapacity:3];

// create a standard "add" button
UIBarButtonItem* bi = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:NULL];
bi.style = UIBarButtonItemStyleBordered;
[buttons addObject:bi];
[bi release];

// create a spacer
bi = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
[buttons addObject:bi];
[bi release];

// create a standard "refresh" button
bi = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh target:self action:@selector(refresh:)];
bi.style = UIBarButtonItemStyleBordered;
[buttons addObject:bi];
[bi release];

// stick the buttons in the toolbar
[tools setItems:buttons animated:NO];

[buttons release];

// and put the toolbar in the nav bar
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:tools];
[tools release];

@ tc.:

我试图继承UIToolbar.

// MyToolbar.h

#import <Foundation/Foundation.h>


@interface MyToolbar : UIToolbar {

}

@end

// MyToolbar.m

#import "MyToolbar.h"


@implementation MyToolbar

- (void)drawRect:(CGRect)rect {
    // do nothing
}

- (id)initWithFrame:(CGRect)aRect {
    if ((self = [super initWithFrame:aRect])) {
        self.opaque = NO;
        self.backgroundColor = [UIColor clearColor];
        self.clearsContextBeforeDrawing = YES;      
    }
    return self;
}

@end

Answer 1

无法保证UIToolbar在UINavigationBar中无缝绘制; 这可能是你所看到的白线的原因.

您可能能够将UIToolbar子类化,以便它不会绘制(即覆盖-drawRect:不执行任何操作).