How to customize the month cell of Calendar with custom object in Xamarin.Forms (SfCalendar)

You can customize the month cell of Calendar control with custom object by customizing the

CellTemplate property in MonthViewSettings.

You can also refer the following article.

https://www.syncfusion.com/kb/8588/how-to-customize-the-month-cell-of-calendar-with-custom-object-in-xamarin-forms-sfcalendar

C#

CalendarPageModel defined as custom object to bind in CellTemplate

public class CalendarPageModel : INotifyPropertyChanged
    {
        Random random = new Random();
        public bool IsCurrentMonth { get; set; }
        public string Title { get; set; }
        public string Temperature { get; set; }
        public string Wind { get; set; }
        public string Humidity { get; set; }
        public DateTime Date { get; set; }

        private double celcius;

        public double Celcius
        {
            get
            {
                return celcius;
            }

            set
            {
                celcius = value; OnPropertyChanged("Celcius");
            }
        }

        private string image;

        public event PropertyChangedEventHandler PropertyChanged;

        public string Image
        {
            get
            {
                return image;
            }

            set
            {
                image = value;
                OnPropertyChanged("Image");
            }
        }

        public CalendarPageModel(bool iscurrentmonth, DateTime date)
        {
            IsCurrentMonth = iscurrentmonth;
            this.Date = date;
            this.Title = " ";
            this.Temperature = " ";
            this.Wind = " ";
            this.Humidity = " ";
            if (IsCurrentMonth)
            {
                UpdateCelcius();

            }
        }

        private void UpdateCelcius()
        {
            if (this.Date.Day % 5 == 0)
            {
                this.Celcius = 50;
            }
            else if (this.Date.Day % 3 == 0)
            {
                this.Celcius = 80;
            }
            else
            {
                this.Celcius = 120;
            }

            if (Celcius > 10 && Celcius < 60)
            {
                this.Image = "sunrain.png";
            }
            else if (Celcius > 60 && Celcius < 100)
            {
                this.Image = "sun1.png";
            }
            else
            {
                this.Image = "sun.png";
            }
        }

        private void OnPropertyChanged(string propertyName)
        {
            this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

XAML

CellTamplate customized with CalendarPageModel custom object property by binding.

<ContentPage.Resources>
        <ResourceDictionary>
            <DataTemplate x:Key="weathertemplate">
                <Grid BackgroundColor="White" 
                                  HorizontalOptions="Center">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="*" />
                        <RowDefinition Height="2*" />
                    </Grid.RowDefinitions>
                    <Label Text="{Binding Date.Day}" 
                                       HorizontalTextAlignment="Center"
                                       IsVisible="{Binding IsCurrentMonth}" 
                                       VerticalTextAlignment="Center" 
                                       VerticalOptions="FillAndExpand" 
                                       HorizontalOptions="FillAndExpand" 
                                       TextColor="Black" 
                                       FontAttributes="None" 
                                       FontSize="10" />
                    <Grid Grid.Row="1" 
                                      IsVisible="{Binding IsCurrentMonth}">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="2*" />
                            <RowDefinition Height="*" />
                        </Grid.RowDefinitions>
                        <Grid Grid.Row="1" 
                                          HorizontalOptions="Center" 
                                          VerticalOptions="Center">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*" />
                                <ColumnDefinition Width="*" />
                            </Grid.ColumnDefinitions>
                            <Label Text="{Binding Celcius}" 
                                               HorizontalTextAlignment="End" 
                                               VerticalTextAlignment="Center"
                                               VerticalOptions="FillAndExpand" 
                                               HorizontalOptions="FillAndExpand" 
                                               TextColor="Black" 
                                               FontAttributes="None" 
                                               FontSize="8" 
                                               WidthRequest="20" 
                                               HeightRequest="20" />
                            <Label Grid.Column="1" 
                                               Text="C" 
                                               FontSize="8" />
                        </Grid>
                        <Image Source="{Binding Image}" 
                                           WidthRequest="20" 
                                           HeightRequest="20" 
                                           HorizontalOptions="Center" 
                                           VerticalOptions="Center" />
                    </Grid>
                </Grid>
            </DataTemplate>
        </ResourceDictionary>
    </ContentPage.Resources>
    <ContentPage.Content>
        <Syncfusion:SfCalendar x:Name="calendar" >
            <syncfusion:SfCalendar.MonthViewSettings>
                <Syncfusion:MonthViewSettings DateSelectionColor="#dddddd" CellTemplate="{StaticResource weathertemplate}"/>
            </syncfusion:SfCalendar.MonthViewSettings>
        </Syncfusion:SfCalendar>
    </ContentPage.Content>
    <ContentPage.Behaviors>
        <local:CalendarBehavior/>
    </ContentPage.Behaviors>
</ContentPage>

C#

Using CellBindingContext property in the argument of OnMonthCellLoaded event to pass custom object on OnMonthCellLoaded event.

private void Calendar_OnMonthCellLoaded(object sender, MonthCellLoadedEventArgs e)
{
    CalendarPageModel cellBindingContext = new CalendarPageModel(e.IsCurrentMonth, e.Date);
    e.CellBindingContext = cellBindingContext;
}

Output