我不能让这个工作。我有一个视图)，它包含一个数据网格，填充了一个可观察集合(MyDataCollection)的项目。MyDataCollection的每一项都有不同的属性(Name, Description，…)日志)。日志本身是一个可观察的日志项集合。每个日志项都有不同的属性(日期，人物，…)。
用MyDataCollection的项填充的数据网格每行集有一个工具提示。这样的:
<DataGrid ItemsSource="{Binding MyDataCollection}">
<DataGrid.RowStyle>
<Style TargetType="DataGridRow">
<Setter Property="ToolTip">
<Setter.Value>
<Border>
<Grid Margin="5" MaxWidth="400">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
...
</Grid.RowDefinitions>
...
<DataGrid x:Name="LogsGrid" Grid.Row="6" ItemsSource="{Binding PlacementTarget.DataContext.Logs, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ToolTip}}">
<DataGrid.Columns>
<DataGridTextColumn Header="Date"
Binding="{Binding Date}"
/>
<DataGridTextColumn Header="Person"
Binding="{Binding Person.FullName}"
/>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Border>
</Setter.Value>
</Setter>
</Style>
</DataGrid.RowStyle>
</DataGrid>
我可以看到工具提示，我可以看到工具提示中的数据网格，标题为"日期"one_answers"人"，但网格内容是空的。看起来绑定设置不正确。有人能帮我一下吗?由于
更新1:mydatacolllecollection包含我的自定义类"Car"的对象。下面是Car的定义:
public class Car : INotifyPropertyChanged
{
public string name;
public string description;
public Contact assignedTo;
public ObservableCollection<Log> logs = new ObservableCollection<Log>();
public string Name
{
get
{
return this.name;
}
set
{
if (this.name != value)
{
this.name = value;
NotifyPropertyChanged("Name");
}
}
}
public string Description
{
get
{
return this.description;
}
set
{
if (this.description != value)
{
this.description = value;
NotifyPropertyChanged("Description");
}
}
}
public Contact AssignedTo
{
get
{
return this.assignedTo;
}
set
{
if (this.assignedTo != value)
{
this.assignedTo = value;
NotifyPropertyChanged("AssignedTo");
}
}
}
public ObservableCollection<Log> Logs
{
get
{
return this.logs;
}
private set //TODO : Check if this is correct
{
if (this.logs != value)
{
this.logs = value;
NotifyPropertyChanged("Logs");
}
}
}
public Car()
{
// TODO: Delete this: (only here for testing)
Contact c = new Contact();
c.Name = "Test";
c.LastName = "Test";
for (int i = 0; i < 4; i++)
AddLog(DateTime.Now, c, new TimeSpan(2, 0, 0));
}
public void AddLog(DateTime date, Contact person, TimeSpan time)
{
Log newLog = new Log(date, person, time);
Logs.Add(newLog);
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string propName)
{
if (this.PropertyChanged != null)
this.PropertyChanged(this, new PropertyChangedEventArgs(propName));
}
}
我的Log Class是:
public class Log : INotifyPropertyChanged
{
DateTime date;
Contact person;
TimeSpan time;
public DateTime Date
{
get
{
return this.date;
}
set
{
if (this.date != value)
{
this.date = value;
NotifyPropertyChanged("Date");
}
}
}
public Contact Person
{
get
{
return this.person;
}
set
{
if (this.person != value)
{
this.person = value;
NotifyPropertyChanged("Person");
}
}
}
public TimeSpan Time
{
get
{
return this.time;
}
set
{
if (this.time != value)
{
this.time = value;
NotifyPropertyChanged("Time");
}
}
}
public Log(DateTime date, Contact person, TimeSpan time)
{
this.date = date;
this.person = person;
this.time = time;
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string propName)
{
if (this.PropertyChanged != null)
this.PropertyChanged(this, new PropertyChangedEventArgs(propName));
}
}
我在你的代码中唯一能找到的对我来说不完美的是Mode=TwoWay在LogsGrid.ItemsSource上的绑定。这给我抛出了一个异常，因为它告诉Binding，您希望LogsGrid将ItemsSource的新值写回Binding源-在这种情况下，到视图模型的Logs属性。这不仅不是您想要的，而且实际上是不可能的，因为Logs有一个私有setter(而且DataGrid无论如何都不会这样做)。因此出现了例外。
UpdateSourceTrigger=PropertyChanged是另一个没有作用的参数，尽管这次没有什么害处:它告诉它何时将新的Logs集合写回Car.Logs。但是，DataGrid不能这样做。它不会为属性创建新的值。TextBox将为源属性分配新的Text值，这就是TextBox的作用。但DataGrid没有这样做。
当我去掉这两个东西时，它对我来说工作得很好:
<DataGrid x:Name="LogsGrid" Grid.Row="6" ItemsSource="{Binding Logs}">
<!-- etc. -->
用ItemsSource="{Binding PlacementTarget.DataContext.Logs, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ToolTip}}">代替ItemsSource="{Binding Logs, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">。