【iOS开发】UITextField、UITextView只限输入中文、英文、数字及实时限制字符个数封装实现

1、一个字母、符号、数字相当于一个字符
2、一个汉字相当于两个字符
3、不能输入特殊字符
4、不能输入emoji表情
5、不能输入空格

一、注册通知

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textFieldChange:) name:UITextFieldTextDidChangeNotification object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textFieldChange:) name:UITextViewTextDidChangeNotification object:nil];

二、通知实现

- (void)textFieldChange:(UITextField *)textField
{
    //判断输入(不能输入特殊字符)
    [RestrictionInput restrictionInputTextField:self.titleTextField maxNumber:100 showView:self showErrorMessage:@"商品名称0~100字符~"];

    [RestrictionInput restrictionInputTextView:self.infoTextView maxNumber:200 showView:self showErrorMessage:@"商品描述0~200字符~"];

}

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    if ([RestrictionInput isInputRuleAndBlank:text] || [text isEqualToString:@""]) {//当输入符合规则和退格键时允许改变输入框
        return YES;
    } else {
        return NO;
    }
}

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if ([RestrictionInput isInputRuleAndBlank:string] || [string isEqualToString:@""]) {//当输入符合规则和退格键时允许改变输入框
        return YES;
    } else {
        return NO;
    }
}

三、封装类（RestrictionInput）

.h

#import 

@interface RestrictionInput : NSObject

+ (void)restrictionInputTextField:(UITextField *)inputClass maxNumber:(NSInteger)maxNumber showView:(UIView *)showView showErrorMessage:(NSString *)errorMessage;

+ (void)restrictionInputTextView:(UITextView *)inputClass maxNumber:(NSInteger)maxNumber showView:(UIView *)showView showErrorMessage:(NSString *)errorMessage;

+ (BOOL)isInputRuleAndBlank:(NSString *)str;

.m

#import "RestrictionInput.h"

@implementation RestrictionInput

+ (void)restrictionInputTextField:(UITextField *)inputClass maxNumber:(NSInteger)maxNumber showView:(UIView *)showView showErrorMessage:(NSString *)errorMessage
{

    NSString *toBeString = inputClass.text;

    if (![self isInputRuleAndBlank:toBeString]) {
        inputClass.text = [self disable_emoji:toBeString];
        return;
    }

    NSString *lang = [[inputClass textInputMode] primaryLanguage]; // 获取当前键盘输入模式
    if([lang isEqualToString:@"zh-Hans"]) { //简体中文输入,第三方输入法（搜狗）所有模式下都会显示“zh-Hans”
        UITextRange *selectedRange = [inputClass markedTextRange];
        //获取高亮部分
        UITextPosition *position = [inputClass positionFromPosition:selectedRange.start offset:0];
        //没有高亮选择的字，则对已输入的文字进行字数统计和限制
        if(!position) {
            NSString *getStr = [self getSubString:toBeString maxNumber:maxNumber];
            if(getStr && getStr.length > 0) {
                inputClass.text = getStr;
                [showView showHudText:errorMessage hideDelay:1.0 completionBlock:nil];

                NSLog(@"%@", inputClass.text);
            }
        }
    } else{
        NSString *getStr = [self getSubString:toBeString maxNumber:maxNumber];
        if(getStr && getStr.length > 0) {
            inputClass.text= getStr;
            [showView showHudText:errorMessage hideDelay:1.0 completionBlock:nil];
            NSLog(@"%@",inputClass.text);
        }
    }
}

+ (void)restrictionInputTextView:(UITextView *)inputClass maxNumber:(NSInteger)maxNumber showView:(UIView *)showView showErrorMessage:(NSString *)errorMessage
{
    NSString *toBeString = inputClass.text;

    if (![self isInputRuleAndBlank:toBeString]) {
        inputClass.text = [self disable_emoji:toBeString];
        return;
    }

    NSString *lang = [[inputClass textInputMode] primaryLanguage]; // 获取当前键盘输入模式
    if([lang isEqualToString:@"zh-Hans"]) { //简体中文输入,第三方输入法（搜狗）所有模式下都会显示“zh-Hans”
        UITextRange *selectedRange = [inputClass markedTextRange];
        //获取高亮部分
        UITextPosition *position = [inputClass positionFromPosition:selectedRange.start offset:0];
        //没有高亮选择的字，则对已输入的文字进行字数统计和限制
        if(!position) {
            NSString *getStr = [self getSubString:toBeString maxNumber:maxNumber];
            if(getStr && getStr.length > 0) {
                inputClass.text = getStr;
                [showView showHudText:errorMessage hideDelay:1.0 completionBlock:nil];

                NSLog(@"%@", inputClass.text);
            }
        }
    } else{
        NSString *getStr = [self getSubString:toBeString maxNumber:maxNumber];
        if(getStr && getStr.length > 0) {
            inputClass.text= getStr;
            [showView showHudText:errorMessage hideDelay:1.0 completionBlock:nil];
            NSLog(@"%@",inputClass.text);
        }
    }
}

/**
 *  获得 kMaxLength长度的字符
 */
+ (NSString *)getSubString:(NSString*)string maxNumber:(NSInteger)maxNumber
{
    NSStringEncoding encoding = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
    NSData* data = [string dataUsingEncoding:encoding];
    NSInteger length = [data length];
    if (length > maxNumber) {
        NSData *data1 = [data subdataWithRange:NSMakeRange(0, maxNumber)];
        NSString *content = [[NSString alloc] initWithData:data1 encoding:encoding];//【注意4】：当截取kMaxLength长度字符时把中文字符截断返回的content会是nil
        if (!content || content.length == 0) {
            data1 = [data subdataWithRange:NSMakeRange(0, maxNumber - 1)];
            content =  [[NSString alloc] initWithData:data1 encoding:encoding];
        }
        return content;
    }
    return nil;
}

/**
 * 字母、数字、中文正则判断（不包括空格）
 */
+ (BOOL)isInputRuleNotBlank:(NSString *)str {
    NSString *pattern = @"^[➋➌➍➎➏➐➑➒\a-zA-Z\u4E00-\u9FA5\\d]*$";
    NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", pattern];
    BOOL isMatch = [pred evaluateWithObject:str];
    return isMatch;
}
/**
 * 字母、数字、中文正则判断（包括空格）【注意3】
 */
+ (BOOL)isInputRuleAndBlank:(NSString *)str {

    //九宫格无法输入解决需要加上正则 \➋➌➍➎➏➐➑➒
    NSString *pattern = @"^[➋➌➍➎➏➐➑➒\a-zA-Z\u4E00-\u9FA5\\d\\s]*$";
    NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", pattern];
    BOOL isMatch = [pred evaluateWithObject:str];
    return isMatch;
}

+ (NSString *)disable_emoji:(NSString *)text{
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"[^\\u0020-\\u007E\\u00A0-\\u00BE\\u2E80-\\uA4CF\\uF900-\\uFAFF\\uFE30-\\uFE4F\\uFF00-\\uFFEF\\u0080-\\u009F\\u2000-\\u201f\r\n]"options:NSRegularExpressionCaseInsensitive error:nil];
    NSString *modifiedString = [regex stringByReplacingMatchesInString:text
                                                               options:0
                                                                 range:NSMakeRange(0, [text length])
                                                          withTemplate:@""];
    return modifiedString;
}