Question

我有一个文本字段，用户可以输入他们的出生日期，现在我想确保在保存到数据库之前输入是否为日期格式。我经历了SO，但我仍然没有得到答案。任何人都可以告诉我如何验证（是日期）输入。

日期格式为MM / DD / YYYY

注意：我不希望用户通过日期选择器选择日期。

Answer 1

试试这个

NSString *dateFromTextfield = @"07/24/2013";

   // Convert string to date object
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"MM/dd/yyyy"];// here set format which you want...
    NSDate *date = [dateFormat dateFromString:dateFromTextfield]; 
    [dateFormat release];

然后检查

//set int position to 2 and 5  as it contain / for a valid date
unichar ch = [dateFromTextfield characterAtIndex:position];
NSLog(@"%c", ch);

if (ch == '/') 
{
 //valid date
}
else
 { 
 //not a valid date
}

Answer 2

Convert string to date in my iPhone app

然后检查它是否为零。也许还要检查它是否在你的应用程序的合理范围内

Answer 3

首先，使用UIDatePicker，因为它是专门设计的，这是在iOS平台上选择日期的自然方式。无论如何，如果你想检查来自UITextField的字符串是否是日期，格式化（使用格式化程序），并依赖格式化程序获取日期

NSString *dateAsString = @"2010-05-24" // string from textfield
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd"];
NSDate * dateFromString = [myDateFormatter dateFromString:dateAsString];

如果NSDate不是nil，那就没关系，否则出现问题：用户输入的不是用户输入格式错误的日期或日期。

尝试为用户提供一个提示，例如：'日期应该有格式：yyyy-dd-MM'

Answer 4

NSString *dateFromTextfield = @"07/24/2013";

//Extra validation, because the user can enter UTC date as completely in textfield,
//Here i assumed that you would expect only string lenth of 10 for date
//If more than digits then invalid date.
if ([dateFromTextfield length]>10) {

    //Show alert invalid date

    return;

}

//If you give the correct date format then only date formatter will convert it to NSDate. Otherwise return nil.
//So we can make use of that to find out whether the user has entered date or not.

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"MM/dd/yyyy"];
NSDate *date = [dateFormat dateFromString:dateFromTextfield];
[dateFormat release];

//If date and date object is kind of NSDate class, then it must be a date produced by dateFormat.
if (date!=nil && [date isKindOfClass:[NSDate class]]) {

    //User has entered date
    // '/' and numbers only entered

}
else{

    //Show alert invalid date

    //Other than that date format.
}

输入字符串的验证是否为日期？

4 个答案: