WPF 控件内部调用View绑定属性值

 使用mvvm架构，在某一个自定义控件内部或者DataGrid内部调用外部view的DataContext。

  <TextBlock Text="{Binding DataContext.WatermarkText,RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type settingCtrl:SettingView}}}"/>

 binding里面设置RelativeSource的值即可  注意Binding里面要在数据源之前加 DataContext

<xceedToolkit:WatermarkTextBox Name="TxtSearchBar" Width="262"  FontSize="16" FontFamily="Source Sans Pro"
                                                   VerticalContentAlignment="Center"
                                                   HorizontalAlignment="Stretch"
                                                   Background="#ffffff"
                                                   BorderBrush="#7c868f" 
                                                   BorderThickness="1,1,1,1"
                                                   Text="{Binding SearchValue, UpdateSourceTrigger=PropertyChanged}"
                                                   Margin="10,0,0,0">
                        <xceedToolkit:WatermarkTextBox.WatermarkTemplate>
                            <DataTemplate>
                                <TextBlock Name="txtWatermark" Text="{Binding DataContext.WatermarkText,RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type settingCtrl:SettingView}}}" FontSize="14" Margin="5,0,0,0" Foreground="Gray" />
                            </DataTemplate>
                        </xceedToolkit:WatermarkTextBox.WatermarkTemplate>
                    </xceedToolkit:WatermarkTextBox>