How can I use nested Async (WCF) calls within foreach loops in Silverlight ?
- by Peter St Angelo
The following code contains a few nested async calls within some foreach loops. I know the silverlight/wcf calls are called asyncrously -but how can I ensure that my wcfPhotographers, wcfCategories and wcfCategories objects are ready before the foreach loop start? I'm sure I am going about this all the wrong way -and would appreciate an help you could give.
private void PopulateControl()
{
List<CustomPhotographer> PhotographerList = new List<CustomPhotographer>();
proxy.GetPhotographerNamesCompleted += proxy_GetPhotographerNamesCompleted;
proxy.GetPhotographerNamesAsync();
//for each photographer
foreach (var eachPhotographer in wcfPhotographers)
{
CustomPhotographer thisPhotographer = new CustomPhotographer();
thisPhotographer.PhotographerName = eachPhotographer.ContactName;
thisPhotographer.PhotographerId = eachPhotographer.PhotographerID;
thisPhotographer.Categories = new List<CustomCategory>();
proxy.GetCategoryNamesFilteredByPhotographerCompleted += proxy_GetCategoryNamesFilteredByPhotographerCompleted;
proxy.GetCategoryNamesFilteredByPhotographerAsync(thisPhotographer.PhotographerId);
// for each category
foreach (var eachCatergory in wcfCategories)
{
CustomCategory thisCategory = new CustomCategory();
thisCategory.CategoryName = eachCatergory.CategoryName;
thisCategory.CategoryId = eachCatergory.CategoryID;
thisCategory.SubCategories = new List<CustomSubCategory>();
proxy.GetSubCategoryNamesFilteredByCategoryCompleted += proxy_GetSubCategoryNamesFilteredByCategoryCompleted;
proxy.GetSubCategoryNamesFilteredByCategoryAsync(thisPhotographer.PhotographerId,thisCategory.CategoryId);
// for each subcategory
foreach(var eachSubCatergory in wcfSubCategories)
{
CustomSubCategory thisSubCatergory = new CustomSubCategory();
thisSubCatergory.SubCategoryName = eachSubCatergory.SubCategoryName;
thisSubCatergory.SubCategoryId = eachSubCatergory.SubCategoryID;
}
thisPhotographer.Categories.Add(thisCategory);
}
PhotographerList.Add(thisPhotographer);
}
PhotographerNames.ItemsSource = PhotographerList;
}
void proxy_GetPhotographerNamesCompleted(object sender, GetPhotographerNamesCompletedEventArgs e)
{
wcfPhotographers = e.Result.ToList();
}
void proxy_GetCategoryNamesFilteredByPhotographerCompleted(object sender, GetCategoryNamesFilteredByPhotographerCompletedEventArgs e)
{
wcfCategories = e.Result.ToList();
}
void proxy_GetSubCategoryNamesFilteredByCategoryCompleted(object sender, GetSubCategoryNamesFilteredByCategoryCompletedEventArgs e)
{
wcfSubCategories = e.Result.ToList();
}
