Customize UITextfield of the UISearchbar - iOS

问题:

I'm trying to customize the textfield for the UISearchbar. The picture below shows my half done work.

I have subclasses the UISearchbar and called it from my view controller. I'm trying to remove those dark gray lines from the textfield. Below is the implementation of the UISearchbar adding to subview of the viewcontroller.

searchbar = [[SearchBar alloc] initWithFrame:CGRectMake(35,78, 250, 17)];
searchbar.backgroundColor = [UIColor clearColor];
searchbar.layer.borderColor = [[UIColor clearColor] CGColor];
searchbar.layer.borderWidth = 0;

for(UIView *view in searchbar.subviews){
    if([view isKindOfClass:[UITextField class]]){
        UITextField *tf= (UITextField *)view;
        tf.layer.borderColor = [[UIColor clearColor] CGColor];
        tf.delegate = self;
        break;
    }
}
[self.view addSubview:searchbar];
searchbar.delegate = self;

UISearchBar subclass:

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

-(void)layoutSubviews{
     UITextField *searchField;
     [[[self subviews] objectAtIndex:0] removeFromSuperview];
     [self setTintColor:[UIColor clearColor]];
     self.clipsToBounds = YES;
     NSUInteger numViews = [self.subviews count];
     for(int i = 0; i < numViews; i++) {
        if([[self.subviews objectAtIndex:i] isKindOfClass:[UITextField class]]) { 
            searchField = [self.subviews objectAtIndex:i];
             searchField.leftViewMode = UITextFieldViewModeNever;
             searchField.backgroundColor = [UIColor clearColor];

        }


    }
    if(!(searchField == nil)) {            
        searchField.backgroundColor = [UIColor clearColor];
        searchField.textColor = [UIColor blackColor];
        searchField.frame = CGRectMake(self.frame.origin.x,self.frame.origin.y,self.frame.size.width,self.frame.size.height-10);

        [searchField setBorderStyle:UITextBorderStyleRoundedRect];

    }

    [super layoutSubviews];

}

I'm trying to achive something like this: The textfield should not have any boundaries. The icons are flattened UIImageView.

回答1:

This is an easy way to get textfield from UISearchBar subview hierarchy and set its properties as needed like

  UITextField *txfSearchField = [searchbar valueForKey:@"_searchField"];
[txfSearchField setBackgroundColor:[UIColor whiteColor]];
    [txfSearchField setLeftView:UITextFieldViewModeNever];
    [txfSearchField setBorderStyle:UITextBorderStyleRoundedRect];
    txfSearchField.layer.borderWidth = 8.0f; 
    txfSearchField.layer.cornerRadius = 10.0f;
        txfSearchField.layer.borderColor = [UIColor clearColor].CGColor;

回答2:

Use the following if you don't want to use undocumented features or use an image:

CGSize size = CGSizeMake(30, 30);
// create context with transparent background
UIGraphicsBeginImageContextWithOptions(size, NO, 1);

// Add a clip before drawing anything, in the shape of an rounded rect
[[UIBezierPath bezierPathWithRoundedRect:CGRectMake(0,0,30,30)
                            cornerRadius:2.0] addClip];
[[UIColor whiteColor] setFill];

UIRectFill(CGRectMake(0, 0, size.width, size.height));
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

[self.searchBar setSearchFieldBackgroundImage:image forState:UIControlStateNormal];

回答3:

Starting from IOS-5 you have the appearance proxy, see: http://developer.apple.com/library/ios/#documentation/uikit/reference/UISearchBar_Class/Reference/Reference.html (there are two sections called "Customizing Appearance", check both).

Here's a working example, it modifies all UISearchBars in the app:

[[UISearchBar appearance] setSearchFieldBackgroundImage:[UIImage imageNamed:@"text_box"] forState:UIControlStateNormal];
[[UISearchBar appearance] setImage:[UIImage imageNamed:@"search_icon"] forSearchBarIcon:UISearchBarIconSearch state:UIControlStateNormal];
mysearchBar.tintColor = [UIColor whiteColor];

回答4:

For those still looking for an answer, Apple has added the searchTextField property to UISearchBar in iOS 13. searchTextField is a UISeachTextField which inherits from UITextField.

let searchBar = UISearchBar()
var searchField : UITextField
if #available(iOS 13.0, *) {
    searchField = searchBar.searchTextField
} else {
    searchField = //One of the other methods listed
}

回答5:

Implementation Change Resistant & High Performance

To anyone reading this and wondering how the text field of a search bar can easily be accessed in Swift; you can extend UISearchBar to add a textField property by using the following piece of code which is resistant to underlying implementation changes and caches the found result so it is high performance.

import UIKit

private var foundTextFieldAssociationKey = UInt8()

extension UISearchBar {

  var textField: UITextField {
    get {
      let value = objc_getAssociatedObject(self, &foundTextFieldAssociationKey) as? UITextField

      if value == nil {
        let findInView = (UIView) -> UITextField? = { view in
          for subview in view.subviews {
            if let textField = (subview as? UITextField) ?? findInView(subview) {
              return textField
            }
          }
          return nil
        }

        guard let foundTextField = findInView(self) else {
          fatalError("UISearchBar doesn't seem to have a UITextField anywhere in the view hierarchy")
        }

        textField = foundTextField
        return foundTextField
      }

      return value!
    }
    set {
      objc_setAssociatedObject(self, &foundTextFieldAssociationKey, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_ASSIGN)
    }
  }

}

If you wish to change the name of the property, make sure you don't change it to searchField. That will mess your search bar up.

回答6:

I have found for iOS 10 I need to do this (borrowed from above and adapted quickly)

extension UISearchBar {
    var textField: UITextField? {

    func findInView(_ view: UIView) -> UITextField? {
        for subview in view.subviews {
            print("checking \(subview)")
            if let textField = subview as? UITextField {
                return textField
            }
            else if let v = findInView(subview) {
                return v
            }
        }
        return nil
      }

      return findInView(self)
    }
 }  

回答7:

Short and Simple

extension UISearchBar {
    var textField:UITextField {
        guard let txtField = self.value(forKey: "_searchField") as? UITextField else {
            assertionFailure()
            return UITextField()
        }
        return txtField
    }
}

回答8:

iOS 13.x & Swift 5.x:

Do the following to access the UITextField in UISearchBar.

extension UISearchBar {

    /// Returns the`UITextField` that is placed inside the text field.
    var textField: UITextField {
        if #available(iOS 13, *) {
            return searchTextField
        } else {
            return self.value(forKey: "_searchField") as! UITextField
        }
    }

}

回答9:

Now in iOS 13 you have searchTextField property to directly access the text field.