原文: 【C#】wpf自定義calendar日期選擇控件的樣式
首先上圖，看下樣式
1. 總覽：
Calendar本質上是一個6x7的清單，這個清單可以用ItemsControl來實作。其填充的每一個item都是一個自定義樣式的Button，Button外面是一個圓形的border。根據Button按鈕的IsEnabled狀态，設定foreground以達到灰色不點選的效果。
2. ItemsControl内容的生成：
主要是想辦法生成第一行第一列的日期，其他的日期隻需要DateTime.AddDays(i)即可。代碼參考：
private void SetCalendar(int year, int month)
{
_days.Clear();//請忽略
DateTime datetime = new DateTime(year, month, 1);
int week = (int)datetime.DayOfWeek;//擷取指定月份的1号是周幾
datetime = datetime.AddDays(1 - week);
for (int i = 0; i < 42; i++)
{
_days.Add(datetime.AddDays(i));
}
OnPropertyChanged("Days");//請忽略
} 首先，将目前年月傳入，擷取到目前月份的第一天是周幾，然後推算出ItemsControl的第一行第一列的Datetime，最後就是順次相加即可。
1. 界面的實作
先上代碼：
<Grid Grid.RowSpan="4" Margin="0,54,0,0" Visibility="{Binding IsShowCalendar,Converter={StaticResource BoolToVisibilityCollapseConverter}}" Background="White" Width="350" HorizontalAlignment="Right">
<Grid.RowDefinitions>
<RowDefinition Height="50"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="auto"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
</Grid.RowDefinitions>
<StackPanel HorizontalAlignment="Center" Orientation="Horizontal">
<Button VerticalAlignment="Center" Command="{Binding YearCommand}" CommandParameter="Pre" Style="{StaticResource TransparentButtonStyle}">
<Button.Content>
<TextBlock Text="<" FontSize="20"></TextBlock>
</Button.Content>
</Button>
<TextBlock VerticalAlignment="Center" FontSize="15" Text="{Binding CurrentYear}"></TextBlock>
<Button VerticalAlignment="Center" Command="{Binding YearCommand}" CommandParameter="Next" Style="{StaticResource TransparentButtonStyle}">
<Button.Content>
<TextBlock Text=">" FontSize="20"></TextBlock>
</Button.Content>
</Button>
<Button Margin="50,10,10,10" VerticalAlignment="Center" Command="{Binding MonthCommand}" CommandParameter="Pre" Style="{StaticResource TransparentButtonStyle}">
<Button.Content>
<TextBlock Text="<" FontSize="20"></TextBlock>
</Button.Content>
</Button>
<TextBlock VerticalAlignment="Center" Text="{Binding CurrentMonth}" FontSize="15"></TextBlock>
<Button VerticalAlignment="Center" Command="{Binding MonthCommand}" CommandParameter="Next" Style="{StaticResource TransparentButtonStyle}">
<Button.Content>
<TextBlock Text=">" FontSize="20"></TextBlock>
</Button.Content>
</Button>
</StackPanel>
<UniformGrid Grid.Row="1" Columns="7">
<TextBlock Text="MON" TextAlignment="Center"></TextBlock>
<TextBlock Text="TUE" TextAlignment="Center"></TextBlock>
<TextBlock Text="WED" TextAlignment="Center"></TextBlock>
<TextBlock Text="THU" TextAlignment="Center"></TextBlock>
<TextBlock Text="FRI" TextAlignment="Center"></TextBlock>
<TextBlock Text="SAT" TextAlignment="Center"></TextBlock>
<TextBlock Text="SUN" TextAlignment="Center"></TextBlock>
</UniformGrid>
<ItemsControl Grid.Row="2" ScrollViewer.HorizontalScrollBarVisibility="Auto"
ScrollViewer.VerticalScrollBarVisibility="Auto"
ItemsSource="{Binding Days}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button Background="{Binding Converter={StaticResource BACKUP_DateTimeToColorConverter}}" Style="{StaticResource CalendarTransparentButtonStyle}"
Content="{Binding Converter={StaticResource BACKUP_DateTimeToDayConverter}}"
Command="{Binding DataContext.ChooseDateCommand,RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type Window}}}" CommandParameter="{Binding}"
MouseDoubleClick="Button_MouseDoubleClick">
<Button.Foreground>
<MultiBinding Converter="{StaticResource BACKUP_DateTimeToForegroundMultiConverter}">
<Binding></Binding>
<Binding Path="DataContext.CurrentMonth" RelativeSource="{RelativeSource FindAncestor,AncestorType={x:Type Window}}"></Binding>
</MultiBinding>
</Button.Foreground>
<Button.IsEnabled>
<MultiBinding Converter="{StaticResource BACKUP_DateTimeToEnableMultiConverter}">
<Binding></Binding>
<Binding Path="DataContext.CutoffDayBegin" RelativeSource="{RelativeSource FindAncestor,AncestorType={x:Type Window}}"></Binding>
<Binding Path="DataContext.CutoffDayEnd" RelativeSource="{RelativeSource FindAncestor,AncestorType={x:Type Window}}"></Binding>
</MultiBinding>
</Button.IsEnabled>
</Button>
</DataTemplate>
</ItemsControl.ItemTemplate>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<UniformGrid Columns="7"></UniformGrid>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
<StackPanel Grid.Row="3" HorizontalAlignment="Center" VerticalAlignment="Bottom" Margin="0,0,0,31" Orientation="Horizontal">
<Button Content="Cancel" Style="{StaticResource btnSecondaryStyle}" Grid.Row="2" Command="{Binding HideCalendarCommand}"></Button>
<Button Content="{Binding CalendarSetText}" Style="{StaticResource btnPrimaryStyle}" Grid.Row="2" Command="{Binding HideCalendarCommand}"></Button>
</StackPanel>
</Grid> 其中，大量用到了Binding和MVVM，如果對方面還不是很紮實，可以參考下
劉鐵錳的視訊.
這段代碼中，主要部分是ItemsControl的ItemsSource綁定。這裡綁定的是Days,其類型是
public ObservableCollection<DateTime> _days = new ObservableCollection<DateTime>();
public ObservableCollection<DateTime> Days
{
get
{
return _days;
}
} 在設定Button的前景色和IsEnabled狀态的時候，你也看到了用的是MultiBinding，并定義了兩個Converter：
1. DateTimeToForegroundMultiConverter
class DateTimeToForegroundMultiConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
DateTime dt=new DateTime();
if(values[0] is DateTime)
{
dt = (DateTime)values[0];
}
int currentMonth;
Int32.TryParse(values[1].ToString(), out currentMonth);
if (dt.Month == currentMonth)
{
if(dt.ToShortDateString()==DateTime.Now.ToShortDateString())
{
return new SolidColorBrush(Colors.White);
}
else
{
return new SolidColorBrush(Colors.Black);
}
}
else
{
return new SolidColorBrush(Colors.Gray);
}
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
return null;
}
} 2. DateTimeToEnableMultiConverter
class DateTimeToEnableMultiConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
DateTime currentDay, cutoffDayBegin,cutoffDayEnd;
if(values[0] is DateTime&&values[1] is DateTime&&values[2] is DateTime)
{
currentDay = (DateTime)values[0];
cutoffDayBegin = (DateTime)values[1];
cutoffDayEnd = (DateTime)values[2];
if (DateTime.Compare(currentDay, cutoffDayBegin) >= 0 && DateTime.Compare(currentDay, cutoffDayEnd) <= 0)
{
return true;
}
else
{
return false;
}
}
else
{
return false;
}
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
return null;
}
} 2. 背景ViewModel的實作
其實背景沒有什麼代碼，有一個SetCalendar方法，在月份或者年份發生變動的時候調用一下即可。
private void SetCalendar(int year, int month)
{
_days.Clear();
DateTime datetime = new DateTime(year, month, 1);
int week = (int)datetime.DayOfWeek;
datetime = datetime.AddDays(1 - week);
for (int i = 0; i < 42; i++)
{
_days.Add(datetime.AddDays(i));
}
OnPropertyChanged("Days");
} 還有一個就是Button點選之後的Command指令：
private void exeChooseDate(object obj)
{
DateTime dt;
DateTime.TryParse(obj.ToString(), out dt);
CurrentMonth = dt.Month;
CurrentYear = dt.Year;
} Button每點選一次，就會執行一次這個方法，CurrentMonth和CurrentYear這兩個屬性的值就會被更改，一些來決定是否需要重新繪制UI切換的上一個/下一個月份。
CurrentMonth和CurrentYear屬性見下：
private int _currentYear = 2010;
public int CurrentYear
{
get
{
return _currentYear;
}
set
{
if (_currentYear != value && value > 1978 && value < 9999)
{
_currentYear = value;
OnPropertyChanged("CurrentYear");
SetCalendar(_currentYear, CurrentMonth);
}
}
}
private int _currentMonth = 1;
public int CurrentMonth
{
get
{
return _currentMonth;
}
set
{
if (_currentMonth != value && value < 13 && value > 0)
{
_currentMonth = value;
OnPropertyChanged("CurrentMonth");
SetCalendar(CurrentYear, _currentMonth);
}
}
}