UITextField开发相关

最大长度maxLength

• 银行卡分割长度、UITextField空格输入
• 关闭键盘的自动纠错功能
  • self.textField.autocorrectionType = UITextAutocorrectionTypeNo;

最大长度maxLength

@interface UITextField (BN)
@property (nonatomic, assign) NSUInteger maxLength;
- (NSString *)getValue;

@end
----------------------------------------------------------------
#import "UITextField+BN.h"
#import <objc/runtime.h>

@interface UITextFieldMaxLengthObserver: NSObject
@end

@implementation UITextFieldMaxLengthObserver

- (void)textChange:(UITextField *)textField {
    NSString *destText = textField.text;
    NSUInteger maxLength = textField.maxLength;
    
    // 对中文的特殊处理，shouldChangeCharactersInRangeWithReplacementString 并不响应中文输入法的选择事件
    // 如拼音输入时，拼音字母处于选中状态，此时不判断是否超长
    UITextRange *selectedRange = [textField markedTextRange];
    if (!selectedRange || !selectedRange.start) {
        if (destText.length > maxLength) {
            textField.text = [destText substringToIndex:maxLength];
        }
    }
}

@end

static UITextFieldMaxLengthObserver *observer;

@implementation UITextField (BN)

+ (void)load {
    observer = [[UITextFieldMaxLengthObserver alloc] init];
}

- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)setMaxLength:(NSUInteger)maxLength {
    objc_setAssociatedObject(self, @selector(maxLength), @(maxLength), OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    if (maxLength) {
        [self addTarget:observer action:@selector(textChange:) forControlEvents:UIControlEventEditingChanged];
    }
}

- (NSUInteger)maxLength {
    NSNumber *number = objc_getAssociatedObject(self, @selector(maxLength));
    return [number integerValue];
}

- (NSString *)getValue {
    return self.text;
}

@end