在WPF中将DataPresenter与DataTemplate一起使用时销毁视图

Question

I'm currently using a ContentPresenter to display different views in a UserControl like this :

 <ContentPresenter Content="{Binding ContentSourceVm}"/>

Each values set to ContentSourceVm are mapped to DataTemplates:

 <DataTemplate DataType="{x:Type adminViewModel:AdminAccountViewModel}">
    <administration:AdminAccountView/>
 </DataTemplate>
 <DataTemplate DataType="{x:Type adminViewModel:AdminCalibrationViewModel}">
    <administration:AdminCalibrationView/>
 </DataTemplate>

When I set a new VM to ContentSourceVm, the view is correctly changed but unfortunately the first view is not freed even after a certain amount of time. (the destructor of the previous view is not called)

What is the best practice to manage this?

I've look for solution using DataTemplateSelector but without success. I've seen some example which send the type of the view using the messenger to free the view associatated to the view model during the dispose of this one but I do not want to create strong relation between my VM and my View.

Thanks!

Answer 1

in ViewModel,before you change the view model with new view models,dispose the current one :

private _contentSourceVm;
prop ContentSourceVm
{
  get
   {
     return _contentSourceVm;
   }
  set
   {
     IDisposable disp=_contentSourceVm as IDisposable ;
     if(disp!=null)
     {
      disp.Dispose();
     }
     _contentSourceVm=value;
     OnpropertyChnaged();
   }
}