windowsforms-devexpress-dot-xtrascheduler-dot-schedulercontrol-e940ea70.md
Enables the backgrounds of appointments to be painted manually.
Namespace : DevExpress.XtraScheduler
Assembly : DevExpress.XtraScheduler.v25.2.dll
NuGet Package : DevExpress.Win.Scheduler
public event CustomDrawObjectEventHandler CustomDrawAppointmentBackground
Public Event CustomDrawAppointmentBackground As CustomDrawObjectEventHandler
The CustomDrawAppointmentBackground event's data class is CustomDrawObjectEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| Bounds | Returns the bounding rectangle of the drawing area. |
| Cache | Gets an object which specifies the storage for the pens, fonts and brushes. Use it for custom painting in Scheduler Reports. |
| Graphics | Gets an object used for painting. |
| Handled | Gets or sets whether an event was handled. If it was handled, the default actions are not required. |
| ObjectInfo | Gets information on the painted element. |
The event data class exposes the following methods:
| Method | Description |
|---|---|
| DrawDefault() | Renders the element using the default drawing mechanism. |
| DrawHtml(HtmlTemplate, DxHtmlPainterContext, Action<DxHtmlPainterArgs>) | Paints the required HTML template inside an element that raised this event. The context parameter allows you to assign an object that transfers mouse events to template elements. |
| DrawHtml(HtmlTemplate, Action<DxHtmlPainterArgs>) | Paints the required HTML template inside an element that raised this event. |
| GetDisplayValue(String) | |
| GetValue(String) |
The CustomDrawAppointmentBackground event is raised before the background of an appointment is painted. The event parameter’s CustomDrawObjectEventArgs.ObjectInfo property provides all the information necessary to paint an appointment’s background. The return value of this property should be typecast to the AppointmentViewInfo type.
Set the CustomDrawObjectEventArgs.Handled property to true to prohibit default appointment painting.
This example illustrates how to partially fill the appointment background in gray. The color coverage is dependent on an individually calculated parameter for each appointment.
The colored rectangle is drawn using the GraphicsCache.FillRectangle method.
public static void scheduler_CustomDrawAppointmentBackground(object sender, CustomDrawObjectEventArgs e)
{
AppointmentViewInfo viewInfo = e.ObjectInfo as AppointmentViewInfo;
// Specify the ratio of a completed task to the entire task.
double completenessRatio = 0.25 * ((int)(viewInfo.Appointment.ResourceId) % 4);
// Draw an appointment as usual.
e.DrawDefault();
// Draw a background rectangle.
Rectangle bounds = CalculateEntireAppointmentBounds(viewInfo);
DrawBackGroundCore(e.Cache, bounds, completenessRatio);
// Indicate that no default drawing is required.
e.Handled = true;
}
static Rectangle CalculateEntireAppointmentBounds(AppointmentViewInfo viewInfo)
{
int leftOffset = 0;
int rightOffset = 0;
double scale = viewInfo.Bounds.Width / viewInfo.Interval.Duration.TotalMilliseconds;
if (!viewInfo.HasLeftBorder)
{
double hidden = (viewInfo.Interval.Start - viewInfo.AppointmentInterval.Start).TotalMilliseconds;
leftOffset = (int)(hidden * scale);
}
if (!viewInfo.HasRightBorder)
{
double hidden = (viewInfo.AppointmentInterval.End - viewInfo.Interval.End).TotalMilliseconds;
rightOffset = (int)(hidden * scale);
}
Rectangle bounds = viewInfo.InnerBounds;
return Rectangle.FromLTRB(bounds.Left - leftOffset, bounds.Y, bounds.Right + rightOffset, bounds.Bottom);
}
static void DrawBackGroundCore(DevExpress.Utils.Drawing.GraphicsCache cache, Rectangle bounds, double completenessRatio)
{
cache.FillRectangle(Brushes.LightGray, new Rectangle(bounds.X, bounds.Y, (int)(bounds.Width * completenessRatio), bounds.Height));
}
Public Shared Sub scheduler_CustomDrawAppointmentBackground(ByVal sender As Object, ByVal e As CustomDrawObjectEventArgs)
Dim viewInfo As AppointmentViewInfo = TryCast(e.ObjectInfo, AppointmentViewInfo)
' Specify the ratio of a completed task to the entire task.
Dim completenessRatio As Double = 0.25 * (CInt((viewInfo.Appointment.ResourceId)) Mod 4)
' Draw an appointment as usual.
e.DrawDefault()
' Draw a background rectangle.
Dim bounds As Rectangle = CalculateEntireAppointmentBounds(viewInfo)
DrawBackGroundCore(e.Cache, bounds, completenessRatio)
' Indicate that no default drawing is required.
e.Handled = True
End Sub
Private Shared Function CalculateEntireAppointmentBounds(ByVal viewInfo As AppointmentViewInfo) As Rectangle
Dim leftOffset As Integer = 0
Dim rightOffset As Integer = 0
Dim scale As Double = viewInfo.Bounds.Width / viewInfo.Interval.Duration.TotalMilliseconds
If Not viewInfo.HasLeftBorder Then
Dim hidden As Double = (viewInfo.Interval.Start - viewInfo.AppointmentInterval.Start).TotalMilliseconds
leftOffset = CInt((hidden * scale))
End If
If Not viewInfo.HasRightBorder Then
Dim hidden As Double = (viewInfo.AppointmentInterval.End - viewInfo.Interval.End).TotalMilliseconds
rightOffset = CInt((hidden * scale))
End If
Dim bounds As Rectangle = viewInfo.InnerBounds
Return Rectangle.FromLTRB(bounds.Left - leftOffset, bounds.Y, bounds.Right + rightOffset, bounds.Bottom)
End Function
Private Shared Sub DrawBackGroundCore(ByVal cache As DevExpress.Utils.Drawing.GraphicsCache, ByVal bounds As Rectangle, ByVal completenessRatio As Double)
cache.FillRectangle(Brushes.LightGray, New Rectangle(bounds.X, bounds.Y, CInt((bounds.Width * completenessRatio)), bounds.Height))
End Sub
The following code snippet (auto-collected from DevExpress Examples) contains a reference to the CustomDrawAppointmentBackground event.
Note
The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.
winforms-scheduler-resolve-appointment-conflicts/CS/DXApplication1/Form1.cs#L47
schedulerControl1.AllowAppointmentConflicts += SchedulerControl1_AllowAppointmentConflicts;
schedulerControl1.CustomDrawAppointmentBackground += SchedulerControl1_CustomDrawAppointmentBackground;
winforms-scheduler-resolve-appointment-conflicts/VB/DXApplication1/Form1.vb#L38
AddHandler schedulerControl1.AllowAppointmentConflicts, AddressOf SchedulerControl1_AllowAppointmentConflicts
AddHandler schedulerControl1.CustomDrawAppointmentBackground, AddressOf SchedulerControl1_CustomDrawAppointmentBackground
schedulerControl1.DataStorage.Appointments.Clear()
See Also
AppointmentViewInfoCustomizing
How to: Display Custom Images for Appointments
How to: Hide the Reminder (Bell) Icon for Outdated Appointments in a Series
How to: Custom Paint Day Headers