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Description
This event occurs only if ParseInput is set to True. Write an OnUserInput event handler implement special processing that needs to occur when the user types directly into the TDateTimePicker (rather than selecting with the drop-down calendar or scroll arrows). UserString is the string that the user types, and DateAndTime represents the value of the Date or Time property.
可以在它的onUserInput事件中写下代码来检测输入的
时间格式是否正确，时间格式由：dateFormat来指定
