TextField小结

// 获取高亮部分
UITextRange *selectRange = [tf markedTextRange];
NSString *string = [tf textInRange:selectRange];

获取高亮部分

限制输入

- (void)textFieldDidChanged:(UITextField *)textField {
    
    NSInteger maxLength = 18;
    NSString *regex = @"[^a-zA-Z\\u4e00-\u9fa5·]";
    
    UITextRange *markedRange = textField.markedTextRange;
    UITextPosition *position = [textField positionFromPosition:markedRange.start offset:0];
    
    if (!position) {
        textField.text = [self filterOriginalStr:textField.text withRegex:regex];
        
        if (textField.text.length == 0) {
            // 这儿textField为空
            
            
        } else {
            if (textField.text.length > maxLength) {
                textField.text = [textField.text substringToIndex:maxLength];
            }
            // 这儿为筛选完之后的文本
            
        }
    }
}

- (NSString *)filterOriginalStr:(NSString *)originalStr withRegex:(NSString *)regex {
    
    NSError *error = NULL;
    NSRegularExpression *regexEx = [NSRegularExpression regularExpressionWithPattern:regex options:NSRegularExpressionCaseInsensitive error:&error];
    
    return [regexEx stringByReplacingMatchesInString:originalStr options:NSMatchingReportCompletion range:NSMakeRange(0, originalStr.length) withTemplate:@""];
}