我有一個對象編輯器視圖,它顯示簡單的數據以及對使用TemplateSelector進行模板化的值的解釋。如果原始值得到更新,則解釋值也會更新,反之亦然。在一個簡單的DataTemplate中,它運行良好,但我有一個更復雜的場景,其中值(ushort)表示位圖(標誌字段)。爲此,我使用帶有ItemTemplate的ItemsControl。這可以在值 - >標誌方向上正常工作,但在點擊標誌時不起作用。我在MVVM世界如此不希望被反應在xaml.cs文件的事件......通過TemplateSelector在DataTemplate中進行雙向數據綁定
視圖的資源:
<DataTemplate x:Key="StandardTemplate">
<StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
<TextBox Margin="0" VerticalAlignment="Top" Width="50" Text="{Binding Formatted,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" />
</StackPanel>
</DataTemplate>
<DataTemplate x:Key="BitmapTemplate" >
<ItemsControl ItemsSource="{Binding Flags,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" >
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" HorizontalAlignment="Center" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel HorizontalAlignment="Center" Width="20">
<TextBlock Text="{Binding BitPosition,Converter={StaticResource intConverter},ConverterParameter=1}" HorizontalAlignment="Center" />
<CheckBox HorizontalAlignment="Center" HorizontalContentAlignment="Center" IsChecked="{Binding IsBitSet,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" />
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
<selectors:EditTemplateSelector x:Key="EditSelector" BitmapTemplate="{StaticResource BitmapTemplate}" StandardTemplate="{StaticResource StandardTemplate}" />
它得到的觀點:
<ContentPresenter Content="{Binding Register}" Grid.Row="2" Grid.ColumnSpan="2" Margin="10" ContentTemplateSelector="{StaticResource EditSelector}" />
我的位圖和BitmapBit類:
public class BitmapBit : ObservableObject
{
ushort _bitPosition = 0;
bool _isSet = false;
public BitmapBit(ushort bitPos, bool isSet)
{
_bitPosition = bitPos;
_isSet = isSet;
}
public ushort BitPosition
{
get { return _bitPosition; }
set
{
if (_bitPosition == value)
return;
_bitPosition = value;
RaisePropertyChanged("BitPosition");
}
}
public bool IsBitSet
{
get { return _isSet; }
set
{
if (_isSet == value)
return;
_isSet = value;
RaisePropertyChanged("IsBitSet");
}
}
}
/// <summary>
/// A collection of BitmapBits
/// </summary>
public class Bitmap : ObservableCollection<BitmapBit>
{
const ushort NUMBER_OF_BITS = sizeof(ushort) * 8; // 8 BITS_IN_A_BYTE
protected Bitmap(ushort value) : base()
{
for (ushort i = 0; i < NUMBER_OF_BITS; ++i)
Insert(0, new BitmapBit(bitPos: i, isSet: (value & (1 << i)) != 0));
}
public static Bitmap Create(ushort value)
{
return new Bitmap(value);
}
public static ushort Parse(Bitmap bits)
{
ushort generated = 0;
foreach (BitmapBit bit in bits)
generated += (ushort)(bit.IsBitSet ? 2^bit.BitPosition : 0);
return generated;
}
}
的IsBitSet setter方法被調用,但我認爲問題是,Bitma p沒有涉及位已更改的通知 - 所以標誌設置者永遠不會被調用。當ObservableCollection的成員更改時,如何更新/通知Flags屬性?
啊我看到你在和我的編輯反映了轉換器的刪除 - 正如你正確地指出的是添加一層混淆。潛在的問題現在更清晰我認爲,但我仍然沒有解決方案! – AndyC 2012-03-28 16:42:28
編輯了我的答案 – GazTheDestroyer 2012-03-28 17:37:01
燈泡瞬間!那是缺失的環節;位圖構造現在需要生成位圖的對象,以便標誌可以在位更改時更新。謝謝你帶領我通過! – AndyC 2012-03-28 19:19:29