Styling the cancel button in a UISearchBar

问题:

I have a UISearchBar that has a cancel button (it's displayed using -(void)setShowsCancelButton:animated). I've changed the tintColor of the search bar like this in an attempt to get a grayish searchbar:

UISearchBar *searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 0, 320, 40)];
searchBar.tintColor = [UIColor colorWithWhite:0.8 alpha:1.0];

This is what it looks like now - notice how the cancel button is also gray: http://twitpic.com/c0hte

Is there a way to set the color of the cancel button separately so it looks more like this: http://twitpic.com/c0i6q

回答1:

What you want to do is pretty tough. There is no built-in hook to get at the cancel button.

However, there are a couple of options if you are willing to jimmy open the hood.

First off, UISearchBar is a UIView, and the Cancel button is also a view, which is added into the search bar as a subview, just as you would expect.

I have experimented a little, and can tell you that when the button is onscreen it has a size of 48,30.

So in viewWillAppear, you can do something like this:

1. Find the cancel button view in [searchBar subviews] by looking for one with size 48,30. (There only seems to be one -- this could change...) You could be doubly careful and look for one that is in approximately the correct position (differs in landscape and portrait).

2. Add a subview to the cancel button.

3. The subview should be a UIControl (so that you can set enabled = NO, in order to make sure touch events get to the actual cancel button)

4. It needs to have the right color and rounded corners; you will need to fudge the size for reasons I don't yet understand (55,30 seems to work)

5. This will work if searchBar.showsCancelButton is always YES; if you want it to disappear when not editing the search string, you will need to find a hook to add the overlay each time the cancel button appears.

6. As you can see, this is some ugly tinkering. Do it with eyes wide open.

回答2:

You can use UIAppearance to style the cancel button without iterating subviews of the UISearchBar, but the UIButton header does not currently have any methods annotated with UI_APPEARANCE_SELECTOR.

EDIT: Drill down the subviews till you get that cancel button

But this usually returns nil until searchBar.setShowsCancelButton(true, animated: true) is called.

extension UISearchBar {

var cancelButton : UIButton? {
    if let view = self.subviews.first {
        for subView in view.subviews {
            if let cancelButton = subView as? UIButton {
                return cancelButton
            }
        }
    }
    return nil
}
}

回答3:

In iOS 5.0+, you can use the appearnce proxy.

Before the search bar is showed.:

UIBarButtonItem *searchBarButton = [UIBarButtonItem appearanceWhenContainedIn:[UISearchBar class], nil];
[searchBarButton setBackgroundImage:myCancelButtonImageNormal forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
[searchBarButton setBackgroundImage:myCancelButtonImageHighlighted forState:UIControlStateHighlighted barMetrics:UIBarMetricsDefault];
[searchBarButton setTitleTextAttributes:barButtonTitleTextAttributesNormal forState:UIControlStateNormal];
[searchBarButton setTitleTextAttributes:barButtonTitleTextAttributesHighlighted forState:UIControlStateHighlighted];

If you use [UIButton appearanceWhenContainedIn:[UISearchBar class], nil], it will affect other buttons (e.g. clear button). So, you'd better not use UIButton's appearnce. Try UIBarButtonItem.

回答4:

Change the title of 'Cancel' button:

[[UIButton appearanceWhenContainedIn:[UISearchBar class], nil] setTitle:@"newTitle" forState:UIControlStateNormal];

Swift equivalent:

   let cancelButton = UIButton.appearance(whenContainedInInstancesOf: [UISearchBar.self])
   cancelButton?.setTitle("cancel".localized, for: .normal)

回答5:

Though this might not be exactly relevant to the original question, the solution is still applicable in the larger sense of trying to customize the Cancel button in the UISearchBar. Thought this will help others who are stuck in such a scenario.

My situation was to change the cancel button's title, but with a twist, wherein I did not want to show the cancel button by default but only wanted it to show up, when the user enters the search mode (by clicking inside the search text field). At this instant, I wanted the cancel button to carry the caption "Done" ("Cancel" was giving a different meaning to my screen, hence the customization).

Nevertheless, here's what I did (a combination of caelavel's and Arenim's solutions):

Subclassed UISearchBar as MyUISearchBar with these two methods:

-(void) setCloseButtonTitle: (NSString *) title forState: (UIControlState)state
{
    [self setTitle: title forState: state forView:self];
}

-(void) setTitle: (NSString *) title forState: (UIControlState)state forView: (UIView *)view
{
    UIButton *cancelButton = nil;
    for(UIView *subView in view.subviews){
        if([subView isKindOfClass:UIButton.class])
        {
            cancelButton = (UIButton*)subView;
        }
        else
        {
            [self setTitle:title forState:state forView:subView];
        }
    }

    if (cancelButton)
        [cancelButton setTitle:title forState:state];

}

And in the viewcontroller which uses this Searchbar, the following piece of code takes care of showing the cancel button and customizing its title:

- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
{
    MyUISearchBar *sBar = (MyUISearchBar *)searchBar;
    [sBar setShowsCancelButton:YES];
    [sBar setCloseButtonTitle:@"Done" forState:UIControlStateNormal];   
}

Strangely enough, I did not have to do anything to hide the cancel button, as it is hidden by default, when the search mode is exited.

回答6:

You can find the cancel button by looping through the subviews of the search bar and checking for the class type (instead of the size):

UIButton *cancelButton = nil;
for(UIView *subView in yourSearchBar.subviews){
    if([subView isKindOfClass:UIButton.class]){
    cancelButton = (UIButton*)subView;
    }
}

And then change the tint color:

[cancelButton setTintColor:[UIColor colorWithRed:145.0/255.0 green:159.0/255.0 blue:179.0/255.0 alpha:1.0]];

回答7:

If you want to configure your cancel button on UISearchBar you should get the UIButton object from your UISearchBar object. Example below

UISearchBar *s_bar = [[UISearchBar alloc] initWithFrame:CGRectMake(50,20,300,30)];
s_bar.delegate = self;
s_bar.barStyle = UIBarStyleDefault;
s_bar.showsCancelButton = YES;
UIButton *cancelButton;
for (id button in s_bar.subviews)
{
    if ([button isKindOfClass:[UIButton class]])
    {
        cancelButton=(UIButton*)button;
        break;
    }
}

回答8:

Custom UISearchBar and override method -addSubview:

- (void) addSubview:(UIView *)view {
    [super addSubview:view];

    if ([view isKindOfClass:UIButton.class]) {
        UIButton *cancelButton = (UIButton *)view;
        [cancelButton setBackgroundImage:[UIImage imageNamed:@"xxxx.png"] forState:UIControlStateNormal];
        [cancelButton setBackgroundImage:[UIImage imageNamed:@"yyyy.png"] forState:UIControlStateHighlighted];
    }
}

回答9:

I'll give a detailed answered regarding the UIAppearance technique. First, you need to understand that the cancel button is a private UINavigationButton:UIButton. After some inspection, it appears that UINavigationButton will respond to those UIAppearance selectors:

// inherited from UINavigationButton
@selector(setTintColor:)
@selector(setBackgroundImage:forState:style:barMetrics:)
@selector(setBackgroundImage:forState:barMetrics:)
@selector(setTitleTextAttributes:forState:)
@selector(setBackgroundVerticalPositionAdjustment:forBarMetrics:)
@selector(setTitlePositionAdjustment:forBarMetrics:)
@selector(setBackButtonBackgroundImage:forState:barMetrics:)
@selector(setBackButtonTitlePositionAdjustment:forBarMetrics:)
@selector(setBackButtonBackgroundVerticalPositionAdjustment:forBarMetrics:)

// inherited from UIButton
@selector(setTitle:forState:)

Coincidentally, those selectors match those of a UIBarButtonItem. Meaning the trick is to use two separate UIAppearance to handle the private class UINavigationButton.

/* dual appearance technique by Cœur to customize a UINavigationButton */
Class barClass = [UISearchBar self];

UIBarButtonItem<UIAppearance> *barButtonItemAppearanceInBar = [UIBarButtonItem appearanceWhenContainedIn:barClass, nil];
[barButtonItemAppearanceInBar setTintColor:...];
[barButtonItemAppearanceInBar setBackgroundImage:... forState:... style:... barMetrics:...];
[barButtonItemAppearanceInBar setBackgroundImage:... forState:... barMetrics:...];
[barButtonItemAppearanceInBar setTitleTextAttributes:... forState:...];
[barButtonItemAppearanceInBar setBackgroundVerticalPositionAdjustment:... forBarMetrics:...];
[barButtonItemAppearanceInBar setTitlePositionAdjustment:... forBarMetrics:...];
// only for a backButton in an UINavigationBar, not for a cancelButton in an UISearchBar
//[barButtonItemAppearanceInBar setBackButtonBackgroundImage:... forState:... barMetrics:...];
//[barButtonItemAppearanceInBar setBackButtonTitlePositionAdjustment:... forBarMetrics:...];
//[barButtonItemAppearanceInBar setBackButtonBackgroundVerticalPositionAdjustment:... forBarMetrics:...];

UIButton<UIAppearance> *buttonAppearanceInBar = [UIButton appearanceWhenContainedIn:barClass, nil];
// warning: doesn't work for iOS7+
[buttonAppearanceInBar setTitle:... forState:...];

This will let you customize your Cancel button as much as you want.

回答10:

After you've initialized your UISearchBar, you can probe into it's subviews and customize each of them. Example:

for (UIView *view in searchBar.subviews) {

    //if subview is the button
    if ([[view.class description] isEqualToString:@"UINavigationButton"]) {

        //change the button images and text for different states
        [((UIButton *)view) setEnabled:YES];
        [((UIButton *)view) setTitle:nil forState:UIControlStateNormal];
        [((UIButton *)view) setImage:[UIImage imageNamed:@"button image"] forState:UIControlStateNormal];
        [((UIButton *)view) setBackgroundImage:[UIImage imageNamed:@"button"] forState:UIControlStateNormal];
        [((UIButton *)view) setBackgroundImage:[UIImage imageNamed:@"button_pressed"] forState:UIControlStateSelected];
        [((UIButton *)view) setBackgroundImage:[UIImage imageNamed:@"button_pressed"] forState:UIControlStateHighlighted];

    //if the subview is the background
    }else if([[view.class description] isEqualToString:@"UISearchBarBackground"]) {

        //put a custom gradient overtop the background
        CAGradientLayer *gradient = [CAGradientLayer layer];
        gradient.frame = view.bounds;
        gradient.colors = [NSArray arrayWithObjects:(id)[[some uicolor] CGColor], (id)[[another uicolor] CGColor], nil];
        [view.layer insertSublayer:gradient atIndex:0];

    //if the subview is the textfield
    }else if([[view.class description] isEqualToString:@"UISearchBarTextField"]){

        //change the text field if you wish

    }

}

Worked out great for me! Especially the gradient :)

回答11:

Swift 2.1.1:

There's no simple way to hook in and style the search bar, you need to grab the subview manually from the search bar and then apply your changes.

var cancelButton: UIButton
let topView: UIView = self.customSearchController.customSearchBar.subviews[0] as UIView
for subView in topView.subviews {
 if subView.isKindOfClass(NSClassFromString("UINavigationButton")!) {
    cancelButton = subView as! UIButton
    cancelButton.enabled = true
    cancelButton.setTitle("TestTitle", forState: UIControlState.Normal) // Change to set the title
    cancelButton.setBackgroundImage(UIImage(named: "ImageName"), forState: .Normal) // Change this to set a custom cancel button image, set the title to "" to remove 'Cancel' text
   }
}

回答12:

First of all I'd like to thank @Eliott from this https://stackoverflow.com/a/37381821/1473144

I had to make a few adjustments for his answer to work in my specs that go below. Please, I ask the OP to update the accepted answer as it's VERY outdated.

Swift 3, iOS 10 & Xcode 8.2.1

searchBar.showsCancelButton = true
var cancelButton: UIButton
let topView: UIView = self.searchBar.subviews[0] as UIView
for subView in topView.subviews {
    if let pvtClass = NSClassFromString("UINavigationButton") {
        if subView.isKind(of: pvtClass) {
            cancelButton = subView as! UIButton

            cancelButton.setTitle("", for: .normal)
            cancelButton.tintColor = UIColor.black
            cancelButton.setImage(#imageLiteral(resourceName: "searchX"), for: .normal)
        }
    }

}

回答13:

Well, here is function, which can change Cancel's button label. Modify it, if you want. Usage is:

nStaticReplaceStringInView(mySearchBar, @"Cancel", @"NewCancelButtonLabel");

void nStaticReplaceStringInView(UIView * view, NSString * haystack, NSString * needle)
{
 for(int i=0; i<[view.subviews count]; i++)
 {
  nStaticReplaceStringInView([view.subviews objectAtIndex:i], haystack,needle);
 }
 if([view respondsToSelector:@selector(titleForState:)])
 {
  //NSLog(@"%@ || %@",[view titleForState:UIControlStateNormal], haystack);
  if(NSStrEq([view titleForState:UIControlStateNormal] , haystack))
  {
   [view setTitle: needle forState: UIControlStateNormal];
  }
 }
}

回答14:

- (void) searchBarTextDidBeginEditing:(UISearchBar *)theSearchBar 
{        
    NSArray *arr = [theSearchBar subviews];
    UIButton *cancelButton = [arr objectAtIndex:3];
    [cancelButton setTitle:@"yourtitle" forState:UIControlStateNormal];    
}

Just take a log of arr amd see at which index control lies. In the same way u can set UITextField properties:

    NSArray *arr = [searchbar subviews];
    UITextField *searchfield = [arr objectAtIndex:2];
    [searchfield setTextAlignment:UITextAlignmentRight];

回答15:

I have many UISearchBar items throughout my app, so I wrote this category to add a property so you can access mySearchBar.cancelButton. (If you're new to categories, read more about extending objects with Categories here.)

Keep in mind you should only access this when the Cancel button is visible because UISearchBar seems to create a new button object every time it shows. Don't save the pointer to the cancelButton, just get it when needed:

@interface UISearchBar (cancelButton)

@property (readonly) UIButton* cancelButton;

- (UIButton *) cancelButton;

@end

@implementation UISearchBar (cancelButton)

- (UIButton *) cancelButton {
    for (UIView *subView in self.subviews) {
        //Find the button
        if([subView isKindOfClass:[UIButton class]])
        {
            return (UIButton *)subView;
        }
    }

    NSLog(@"Error: no cancel button found on %@", self);

    return nil;
}

@end

回答16:

stupid way

for(id cc in [SearchBar subviews])
{
    if([cc isKindOfClass:[UIButton class]])
    {
        UIButton *btn = (UIButton *)cc;
        ......
        Do whatever you want
        .......        
    }
}

回答17:

extension UISearchBar {
var cancelButton : UIButton? {
    let topView: UIView = self.subviews[0] as UIView

    if let pvtClass = NSClassFromString("UINavigationButton") {
        for v in topView.subviews {
            if v.isKind(of: pvtClass) {
                return v as? UIButton
            }
        }
    }

    return nil
}
}

回答18:

UISearchBar *searchBar;
[searchBar setShowsCancelButton:YES animated:YES];

UIButton *cancelButton = 
YES == [searchBar respondsToSelector:NSSelectorFromString(@"cancelButton")] ? 
[searchBar valueForKeyPath:@"_cancelButton"] : nil;

cancelButton.titleEdgeInsets = UIEdgeInsetsMake(0, -10, 0, 10);
[cancelButton setTitle:@"New :)" forState:UIControlStateNormal];

回答19:

For iOS 11 and Swift 4. Create a subclass of UISearchController. Override method:

override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        print("layout")
        if let btn = searchBar.subviews[0].subviews[2] as? UIButton {
            btn.frame = CGRect(x: 306, y: 20, width: 53, height: 30)
        }
}