iOS textField限制只能输入金额

1. 指定textfield的键盘类型

_textField.keyboardType = UIKeyboardTypeDecimalPad;

2. 再textfield协议方法shouldChangeCharactersInRange:添加约束

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    NSString * toBeString = [textField.text stringByReplacingCharactersInRange:range withString:string];
    
    // 最大值99999
    if ([toBeString doubleValue] > 99999) {
        return NO;
    }
    
    //限制.后面最多有两位，且不能再输入.
    if ([textField.text rangeOfString:@"."].location != NSNotFound) {
        //有.了 且.后面输入了两位  停止输入
        if (toBeString.length > [toBeString rangeOfString:@"."].location+3) {
            return NO;
        }
        //有.了，不允许再输入.
        if ([string isEqualToString:@"."]) {
            return NO;
        }
    }
    
    //限制首位0，后面只能输入. 或 删除
    if ([textField.text isEqualToString:@"0"]) {
        if (!([string isEqualToString:@"."] || [string isEqualToString:@""])) {
            return NO;
        }
    }
    
    //首位. 前面补全0
    if ([toBeString isEqualToString:@"."]) {
        textField.text = @"0";
        return YES;
    }
    
    //限制只能输入：1234567890.
    NSCharacterSet * characterSet = [[NSCharacterSet characterSetWithCharactersInString:@"1234567890."] invertedSet];
    NSString * filtered = [[string componentsSeparatedByCharactersInSet:characterSet] componentsJoinedByString:@""];
    return [string isEqualToString:filtered];
}

关于退出键盘可参照：iOS 全局改变textField键盘的inputAccessoryView

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