[iOS 文本输入限制]限制输入特定字符串等

来源：互联网发布：时来天地皆同力知乎编辑：程序博客网时间：2024/06/07 12:41

通常我们需要限制输入数字字符字母或者中文等等
一般情况我们用到textfiled的代理方法去做

//-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{    NSCharacterSet *charer = [NSCharacterSet characterSetWithCharactersInString:@"12345"];    NSString *filed  = [[string componentsSeparatedByCharactersInSet:charer] componentsJoinedByString:@""];    if ([filed isEqualToString:string]) {        return NO;    }    return yes;}

这样就可以限制只输入字符串里给出的字符

分享一个
限制只输入数字金额,并且限制输入最大数字,且自动判断输入0后变为小数点的方法

步骤.
设置textfiled的delegate = self;

//-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{    return [ViewController moneyTextField:textField shouldChangeCharactersInRange:range replacementString:string max:1000];}#pragma mark - 限制输入数字以及最大值 方法实现+(BOOL)moneyTextField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string max:(NSInteger)max{    //筛选输入内容确保正确性    NSCharacterSet *characterSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789.\b"];    string = [string stringByReplacingOccurrencesOfString:@" " withString:@""];    if ([string rangeOfCharacterFromSet:[characterSet invertedSet]].location != NSNotFound) {        return NO;    }    BOOL isHasRadixPoint = YES;    //小数点后面的位数    NSInteger RadixPointNum = 2;    NSString *existText = textField.text;    //判断是否含有小数点    if ([existText rangeOfString:@"."].location == NSNotFound) {        isHasRadixPoint = NO;    }    if (string.length > 0) {        unichar newChar = [string characterAtIndex:0];        //开始进入判断文本        if (existText.length>0) {            if ([existText characterAtIndex:0]=='0') {                //当首位是0的时候                if (newChar=='0') {                    //输入是零的时候判断是否有小数点                    if (isHasRadixPoint) {                        return range.location<=2;                    }else{                        return NO;                    }                }else if((newChar > '0' && newChar <= '9') &&existText.length<=1){                    textField.text = @"";                }            }        }        if ((newChar >= '0' && newChar <= '9') || newChar == '.' ) {            if (newChar == '.') {                if (existText.length==0) {                    textField.text = @"0.";                    return NO;                }else{                    return !isHasRadixPoint;                }            }else {                if (isHasRadixPoint) {                    NSRange ran = [existText rangeOfString:@"."];                    return (range.location - ran.location <= RadixPointNum);                } else{                    //小数点前面的位数                    //return existText.length<6;                    if ([textField.text isEqualToString:@"0"]){                        textField.text = @"0.";                    }                    NSString *nowString;                    if (range.length==0) {                        nowString = [NSString stringWithFormat:@"%@%@",textField.text,string];                    }else{                        nowString = [textField.text stringByReplacingCharactersInRange:range withString:string];                    }                    //                    NSString *nowString = [textField.text stringByReplacingCharactersInRange:range withString:string];                    if (nowString.doubleValue>= max) {                        textField.text = [NSString stringWithFormat:@"%ld",max];                        return NO;                    }                    return nowString.doubleValue <= max;                }            }        }else {            return YES;        }    }    return YES;}

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