C# 4 and .NET 4

1172 ❘ ChaPTer 40 cOre Asp.net
Customizing the Calendar Control
Before adding events to the database, you need to modify your calendar display. It would be nice to display all
days where a booking has previously been made in a different color, and prevent such days from being selectable.
This requires that you modify the way you set dates in the calendar and the way day cells are displayed.
You will start with date selection. You need to check for dates where events are booked in three places, and
modify the selection accordingly: 1) when you set the initial date in Page_Load(), 2) when the user attempts
to select a date from the calendar, and 3) when an event is booked and you want to set a new date to prevent
the user from booking two events on the same day before selecting a new date. Because this is going to be a
common feature, you might as well create a private method to perform this calculation. This method should
accept a trial date as a parameter and return the date to use, which will either be the same date as the trial
date, or the next available day after the trial date.
Before adding this method, you need to give your code access to data in the Events table. You can use the
MRBEventData control to do this because this control is capable of populating a DataView. To facilitate this,
add the following private member and property (you may also require a namespace import for System.Data
for this code to work):
private DataView eventData;
private DataView EventData
{
get
{
if (eventData == null)
{
eventData =
MRBEventData.Select(new DataSourceSelectArguments())
as DataView;
}
return eventData;
}
set
{
eventData = value;
}
}
code snippet PCSWebSite3/Default.aspx.cs
The EventData property populates the eventData member with data as it is required, with the results
cached for subsequent use. Here you use the SqlDataSource.Select() method to obtain a DataView.
Next, add this method, GetFreeDate(), to the code-behind file:
private DateTime GetFreeDate(DateTime trialDate)
{
if (EventData.Count > 0)
{
DateTime testDate;
bool trialDateOK = false;
while (!trialDateOK)
{
trialDateOK = true;
foreach (DataRowView testRow in EventData)
{
testDate = (DateTime)testRow["EventDate"];
if (testDate.Date == trialDate.Date)
{
trialDateOK = false;
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