UITextField篇

监听文字改变通知

 NotificationCenter.default.addObserver(self, selector: #selector(textDidChange(_:)), name: .UITextFieldTextDidChange, object: nil)
@objc func textDidChange(_ notification: Notification) {
}

键盘添加完成按钮及事件

swift

public extension UITextField {
    static var doneKey = "doneKey"
    var doneClosure: (()->Void)? {
        set {
            objc_setAssociatedObject(
                self,
                &UITextField.doneKey,
                newValue,
                .OBJC_ASSOCIATION_RETAIN_NONATOMIC
            )
        }
        
        get {
            return objc_getAssociatedObject(self, &UITextField.doneKey) as? ()->Void
        }
    }
    
    func showDoneButton(callback:(()->Void)?) {
        let toolbar = UIToolbar(frame: CGRect(x: 0, y: 0, width: Screen.width, height: 35.0))
        toolbar.tintColor = UIColor.systemBlue
        toolbar.backgroundColor = UIColor(red: 230.0/255.0, green: 230.0/255.0, blue: 230.0/255.0, alpha: 1)
        let flexibleSpaceBtn =  UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.flexibleSpace, target: self, action: nil)
        let doneBtn = UIBarButtonItem(title: "完成", style: UIBarButtonItem.Style.plain, target: self, action: #selector(doneAction))
        toolbar.items = [flexibleSpaceBtn, doneBtn]
        self.inputAccessoryView = toolbar
        
        doneClosure = callback
    }
    
    @objc func doneAction() {
        self.resignFirstResponder()
        doneClosure?()
    }
}

oc
.h文件

#import <UIKit/UIKit.h>
@interface UITextField (XXExtension)
/// 键盘上方显示"完成“按钮
/// @param callback 回调
- (void)xx_showDoneButton:(void(^)(void))callback;
@end

.m文件

#import "UITextField+XXExtension.h"
#import "XXMacros.h"
#import <objc/runtime.h>

@interface UITextField ()
@property (nonatomic, copy) void(^doneBlock)(void);
@end


@implementation UITextField (XXExtension)
#pragma mark - 
- (void)xx_showDoneButton:(void(^)(void))callback {
    UIToolbar *toolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 35)];
    toolbar.tintColor = UIColor.systemBlueColor;
    toolbar.backgroundColor = [[UIColor alloc] initWithRed:230/255.0 green:230/255.0 blue:230/255.0 alpha:1];
    UIBarButtonItem *flexibleSpaceBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
    
    UIBarButtonItem *doneBtn = [[UIBarButtonItem alloc] initWithTitle:@"完成" style:UIBarButtonItemStylePlain target:self action:@selector(xx_doneAction)];
    toolbar.items = @[flexibleSpaceBtn, doneBtn];
    self.inputAccessoryView = toolbar;
    self.doneBlock = callback;
}

- (void)xx_doneAction {
    if (self.doneBlock) {
        self.doneBlock();
    }
}

- (void)setDoneBlock:(void (^)(void))doneBlock {
    objc_setAssociatedObject(self, @selector(doneBlock), doneBlock, OBJC_ASSOCIATION_COPY_NONATOMIC);
}

- (void (^)(void))doneBlock {
    return objc_getAssociatedObject(self, @selector(doneBlock));
}

@end

设置placeholder样式

public extension UITextField {
    func setupPlaceholder(placeholder: String?, color: UIColor, font: UIFont) {
        if placeholder == nil { return }
        let attText = NSMutableAttributedString(string: placeholder!)
        attText.addAttribute(NSAttributedString.Key.foregroundColor, value: color, range: NSRange(location: 0, length: placeholder!.count))
        attText.addAttribute(NSAttributedString.Key.font, value: font, range: NSRange(location: 0, length: placeholder!.count))
        attributedPlaceholder = attText
    }
}