Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Join the Stack Overflow community to: Ask programming questions Answer and help your peers Get recognized for your expertise up vote 1 down vote favorite I have two Date Time variables first period and second period and with each period i have a date range between two date for each period. My issue is that i usually set my dates to null withn i load the page but for these dates i cannot set them to null which i would like rather than setting a specific date. Date Time first Period Begin Date = Date Time. Today. Add Months(-3 Date Time second Period Begin Date = Date Time. Today. Add Months(-2 I would like it set to null so that it will equal to the values selected from the date picker by the user when used to render results. up vote 18 down vote accepted Date Time is a non-nullable value type, so cannot be null. You can use a Nullable< Date Time> for such a thing: Date Time? first Period Begin Date = Date Time. Today. Add Months(-3 Date Time? second Period Begin Date = null; The Date Time structure cant be null. But you can use a nullable Date Time Date Time? date Time; date Time = null; and check for null if (date Time. Has Value) More information: C Nullable Date Time hope this helps Your Answer draft saved draft discarded lang-cs.
Download demo project - 6.09 Kb Download source - 8.85 Kb Contents Introduction The Date Time Picker control shipped with. NET has a very nice look and feel but lacks one important functionality: you can't enter null values. That means if you bind your Date Time Picker control to a Data Set, you run into trouble. Because in a database, it's normal to have nullable Date Time values. Searching the Internet, I found several solutions but I had problems with each of it: Yet another Date Time. Slicker: This control from Nils Jonsson uses the Check Box of the Date Time Picker to indicate null values. I don't like this solution because I wanted a solution consistent with, for example, the Text Box. If you display a null value in a Text Box, you don't use a Check Box to indicate when it's null. You just display nothing. Nullable Date Time Picker: This control from Pham Minh Tri uses another approach. Null values are indicated with an empty Date Time Picker. That's the way I like it but I ran into several problems with this control where things didn't work as expected. Especially I got an ugly exception as soon as I placed the control on a Tab Page and tried to use databinding. Whenever the control was initialized with a null value, this exception occurred: An unhandled exception of type ' System. Component Model. Win32 Exception' occurred in system.windows.forms.dll. When it was initialized with a valid Date Time value, it worked. Well, I had controls with the right look and feel but they didn't work on Tab Pages, and of course I needed them to work on Tab Pages because most of my controls are placed on Tab Pages. So I started to investigate the exception. After a while, I was sure it had something to do with the change of the Date Time Picker. Format property to Custom Format during initialization. And then I found this explanation from Brett Zimmerann: It is the change in Date Time Picker. Format when you.
Sending NULL value in non-mandatory Date/ Time field: Now, once you have a text box with date picker and it is not a mandatory field. The problem will be when there is no date picked, the error returns as Date/ Time field would not accept null value or a weird date of 1857 (or whatever the minimum date is for the database you're using) is automatically filled in Date/ Time field. To overcome this problem, you can define the parameter as follows and it works perfect: The text box is Text Box1 and Date parameter is @ Sdate. On submit button click event which triggers ole DBCommand1 for insert, write: If Text Box1. Text = Then Ole Db Command1. Parameters( @ Sdate ). Value = DBNull. Value Else Ole Db Command1. Parameters( @ Sdate ). Value = Text Box1. Text End If And, with this, you are now able to send Null value to date field without any.
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