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The Date and Time Picker is a control that allows the user to select either a date or a time value. This control provides two objects in one:
One of the advantages of the Date and Time Picker control is that it allows the user to select a time or a date value instead of typing it. This tremendously reduces the likelihood of mistakes.
To create a Date or Time Picker control, add a Date Time Picker control to a dialog box or a form. To programmatically create a Date Time Picker control, declare
CDateTimeCtrl variable and use its Create() method to initialize it. |
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Introduction to the Time Picker |
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After adding a DateTimePicker control to a container, to make it
a Timer Picker control, change its Format property to a Time value.
This changes the control into a spin control:
To programmatically change a CDateTimeCtrl into a time picker, add the
DTS_TIMEFORMAT style. |
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Characteristics of the Time Picker Control |
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The Time Picker control is a spin button made of different sections: the hours value, the minutes value, the optional seconds value, and the optional AM/PM string. To change the time, the user clicks a section and uses either the mouse or the keyboard to increase or decrease that particular value. To change another value, the user must first click it and then use the spin button.
By default, the time displays using the H:MM:SS AM/PM format. This means that the time uses one digit for the hours from 0 to 9, two digits for the minutes from 00 to 59, two digits for the seconds from 00 to 59 and the AM or PM for morning or afternoon. To control how the time displays, set the desired value in the Format property. The possible values are:
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Format |
Used For |
Description |
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h |
Hour for 12-hour basis |
Used to display the hour with one digit if the value is less than 10 |
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hh |
Hour for 12-hour basis |
Used to display the hour with a leading 0 if the value is less than 10 |
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H |
Hour for 24-hour basis |
Used to display the hour with one digit if the value is less than 10 |
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HH |
Hour for 24-hour basis |
Used to display the hour with a leading 0 if the value is less than 10 |
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m |
Minute |
Used to display the minute with one digit if the value is less than 10 |
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mm |
Minute |
Used to display the minute with a leading 0 if the value is less than 10 |
| t |
AM/PM |
Displays the letter A or P for the AM or PM section |
| tt |
AM/PM |
Displays the letters AM or PM for the last section |
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To change the format of the control, call the CDateTimeCtrl::SetFormat() method. By default, after adding the control to the dialog box or container, it assumes the time of the computer when the control was added. If you want to set a different time, call the
CDateTimeCtrl::SetTime() method. It is overloaded with three versions whose syntaxes are: BOOL SetTime(const COleDateTime& timeNew);
BOOL SetTime(const CTime* pTimeNew);
BOOL SetTime(LPSYSTEMTIME pTimeNew = NULL);
To retrieve the time value on the control, you can call the
CDateTimeCtrl::GetTime() method. It also is overloaded with three versions and their syntaxes are: BOOL GetTime(COleDateTime& timeDest) const;
DWORD GetTime(CTime& timeDest) const;
DWORD GetTime(LPSYSTEMTIME pTimeDest) const;
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Time Picker Messages and Events |
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To use the Time Picker, the user must first give it focus. This is done by clicking either one of the sections of the control or by directly clicking one of the arrows of the spin button portion. You also can programmatically give focus to the control by sending an NM_SETFOCUS message.
Once it has focus, the Time Picker control is primarily meant to let the user set a time on the control. To support this, it allows the user to manually edit the time of the control such as typing the hour, the minute, the second, or AM/PM. The Time Picker control is equipped to natively allow or disallow some values. For example, the user cannot type anything else than a digit for the hours, minutes, or second portions and she can type only a, A, p, or P for the AM/PM section. This is the default scenario where you let this object help you control the values that the user can type. To perform these operations, the user can click the portion to change and then click the arrows of the spin button. When the user changes the value of the control, it fires a
DTN_DATETIMECHANGE message.
Instead of using the mouse to change the time, the user can click a portion of the control and press the arrow keys to change the value of that portion. Whenever the user presses one of the arrow keys, the control fires a
DTN_WMKEYDOWN message.
After using the Time Picker control, the user can click somewhere else, which causes the control to loose focus. To programmatically change focus from the control, you can send an
NM_KILLFOCUS message.
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