我想在UIToolbar中创建一个“后退”左箭头边框按钮。

据我所知,获得其中一个的唯一方法是将UINavigationController保留在默认设置,它使用一个用于左侧栏项。但没有办法我可以找到创建一个作为一个UIBarButtonItem,所以我不能在一个标准的UIToolbar,即使他们非常类似于UINavigationBars。

我可以用按钮图像手动创建它,但我在任何地方都找不到源图像。它们有alpha通道边缘,所以截图和剪切不会得到非常通用的结果。

对于我打算使用的每种尺寸和配色方案,除了截图之外还有什么想法吗?

更新:请停止回避问题,并建议我不应该问这个,应该使用UINavigationBar。我的应用程序是Instapaper Pro。它只显示了一个底部工具栏(以节省空间和最大化可读内容区域),我希望在底部放置一个左箭头形状的后退按钮。

告诉我,我不需要这样做不是答案,当然也不值得赏金。


当前回答

您可以通过从Other中提取源图像来找到它们。UIKit ${SDKROOT}/System/Library/Frameworks/UIKit.framework/Other.artwork。modding社区有一些提取它们的工具。一旦你提取图像,你可以写一些代码来根据需要重新着色,并将其设置为按钮图像。你是否真的可以发布这样的东西(因为你正在嵌入派生的艺术品)可能有点冒险,所以你可能需要和律师谈谈。

其他回答

I'm not sure if this would work, but you could try creating a UINavigationController with the default settings to create the button, find the button in the navigation controller's subview hierarchy, call removeFromSuperview on it, destroy the navigation controller, and then add the button as a subview of your toolbar. You may also need to retain and the button before calling removeFromSuperview (and then release it after adding it as subview of your toolbar) to avoid it being deallocated during the process.

首先,你必须找到后退按钮的图像。我使用了一个很好的应用程序,叫做Extractor,它可以从iPhone中提取所有的图形。 在iOS7中,我成功检索了名为UINavigationBarBackIndicatorDefault的图像,它是黑色的,因为我需要红色,所以我使用Gimp将颜色更改为红色。

编辑:

正如btate在他的评论中提到的,没有必要用图像编辑器改变颜色。下面的代码应该可以做到这一点:

imageView.tint = [UIColor redColor];
imageView.image = [[UIImage imageNamed:@"UINavigationBarBackIndicatorDefault"] imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];

然后我创建了一个视图,其中包含一个带有箭头的imageView,一个带有自定义文本的标签,在视图的顶部我有一个带有动作的按钮。然后我添加了一个简单的动画(淡入和平移)。

下面的代码模拟了返回按钮的行为,包括动画。

-(void)viewWillAppear:(BOOL)animated{
        UIImageView *imageView=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"UINavigationBarBackIndicatorDefault"]];
        [imageView setTintColor:[UIColor redColor]];
        UILabel *label=[[UILabel alloc] init];
        [label setTextColor:[UIColor redColor]];
        [label setText:@"Blog"];
        [label sizeToFit];

        int space=6;
        label.frame=CGRectMake(imageView.frame.origin.x+imageView.frame.size.width+space, label.frame.origin.y, label.frame.size.width, label.frame.size.height);
        UIView *view=[[UIView alloc] initWithFrame:CGRectMake(0, 0, label.frame.size.width+imageView.frame.size.width+space, imageView.frame.size.height)];

        view.bounds=CGRectMake(view.bounds.origin.x+8, view.bounds.origin.y-1, view.bounds.size.width, view.bounds.size.height);
        [view addSubview:imageView];
        [view addSubview:label];

        UIButton *button=[[UIButton alloc] initWithFrame:view.frame];
        [button addTarget:self action:@selector(handleBack:) forControlEvents:UIControlEventTouchUpInside];
        [view addSubview:button];

        [UIView animateWithDuration:0.33 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
            label.alpha = 0.0;
            CGRect orig=label.frame;
            label.frame=CGRectMake(label.frame.origin.x+25, label.frame.origin.y, label.frame.size.width, label.frame.size.height);
            label.alpha = 1.0;
            label.frame=orig;
        } completion:nil];

        UIBarButtonItem *backButton =[[UIBarButtonItem alloc] initWithCustomView:view];
}

- (void) handleBack:(id)sender{
}

编辑:

在我看来,更好的方法是使用手势识别器,而不是添加按钮。

UITapGestureRecognizer* tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleBack:)];
[view addGestureRecognizer:tap];
[view setUserInteractionEnabled:YES];

Three20库有一个方法可以做到这一点:

  UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle: @"Title" style:UIBarButtonItemStylePlain 
                                                                target:self action:@selector(foo)];

  UIColor* darkBlue = RGBCOLOR(109, 132, 162);

  TTShapeStyle* style = [TTShapeStyle styleWithShape:[TTRoundedLeftArrowShape shapeWithRadius:4.5] next:
    [TTShadowStyle styleWithColor:RGBCOLOR(255,255,255) blur:1 offset:CGSizeMake(0, 1) next:
    [TTReflectiveFillStyle styleWithColor:darkBlue next:
    [TTBevelBorderStyle styleWithHighlight:[darkBlue shadow]
                                     shadow:[darkBlue multiplyHue:1 saturation:0.5 value:0.5]
                                      width:1 lightSource:270 next:
    [TTInsetStyle styleWithInset:UIEdgeInsetsMake(0, -1, 0, -1) next:
    [TTBevelBorderStyle styleWithHighlight:nil shadow:RGBACOLOR(0,0,0,0.15)
                                        width:1 lightSource:270 next:nil]]]]]];

  TTView* view = [[[TTView alloc] initWithFrame:CGRectMake(0, 0, 80, 35)] autorelease];
  view.backgroundColor = [UIColor clearColor];
  view.style = style;
  backButton.customView = view;


  self.navigationItem.leftBarButtonItem = backButton;

解决方案不使用png。基于这个SO答案:在iPhone TableView单元格中添加小箭头到单元格的右侧

只是水平翻转UITableViewCell !

UIButton *btnBack = [[UIButton alloc] initWithFrame:CGRectMake(0, 5, 70, 20)];

// Add the disclosure
CGRect frm;
UITableViewCell *disclosure = [[UITableViewCell alloc] init];
disclosure.transform = CGAffineTransformScale(CGAffineTransformIdentity, -1, 1);
frm = self.btnBack.bounds;
disclosure.frame = CGRectMake(frm.origin.x, frm.origin.y, frm.size.width-25, frm.size.height);
disclosure.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
disclosure.userInteractionEnabled = NO;
[self.btnBack addSubview:disclosure];

// Add the label
UILabel *lbl = [[UILabel alloc] init];
frm = CGRectOffset(self.btnBack.bounds, 15, 0);
lbl.frame = frm;
lbl.textAlignment = NSTextAlignmentCenter;
lbl.text = @"BACK";
[self addSubview:lbl];

我试图做同样的事情,但我希望后退按钮在导航栏。(我实际上需要一个返回按钮,这将做的不仅仅是返回,所以我必须使用leftBarButtonItem属性)。我尝试了AndrewS建议的,但在导航栏中,它不会看起来像它应该的样子,因为UIButton有点被强制转换为UIBarButtonItem。

但我找到了一个解决办法。我只是在UIButton下面放了一个UIView并为UIBarButtonItem设置了customView。下面是代码,如果有人需要的话:

// initialize button and button view
UIButton *backButton = [UIButton buttonWithType:101];
UIView *backButtonView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, backButton.frame.size.width, backButton.frame.size.height)];

[backButton addTarget:self action:@selector(backButtonTouched:) forControlEvents:UIControlEventTouchUpInside];
[backButton setTitle:@"Back" forState:UIControlStateNormal];
[backButtonView addSubview:backButton];

// set buttonview as custom view for bar button item
UIBarButtonItem *backButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButtonView];
self.navigationItem.leftBarButtonItem = backButtonItem;

// push item to navigationbar items
[self.navigationController.navigationBar setItems:[NSArray arrayWithObject:backButtonItem]];