Why does this C# event handler not respond to this event in this Silverlight application?
- by Edward Tanguay
Can anyone tell me why the following code successfully executes this event:
OnLoadingComplete(this, null);
but never executes this event handler?
void initialDataLoader_OnLoadingComplete(object obj, DataLoaderArgs args)
CODE:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Controls;
using System.Diagnostics;
namespace TestEvent22928
{
public partial class MainPage : UserControl
{
public MainPage()
{
InitializeComponent();
DataLoader initialDataLoader = new DataLoader("initial");
initialDataLoader.RegisterText("test1", "http://test:111/testdata/test1.txt");
initialDataLoader.RegisterText("test2", "http://test:111/testdata/test2.txt");
initialDataLoader.BeginLoading();
initialDataLoader.OnLoadingComplete += new DataLoader.LoadingComplete(initialDataLoader_OnLoadingComplete);
}
void initialDataLoader_OnLoadingComplete(object obj, DataLoaderArgs args)
{
Debug.WriteLine("loading complete"); //WHY DOES EXECUTION NEVER GET HERE?
}
}
public class DataManager
{
public DataLoader CreateDataloader(string dataloaderIdCode)
{
DataLoader dataLoader = new DataLoader(dataloaderIdCode);
return dataLoader;
}
}
public class DataLoader
{
public string IdCode { get; set; }
public List<DataItem> DataItems { get; set; }
public delegate void LoadingComplete(object obj, DataLoaderArgs args);
public event LoadingComplete OnLoadingComplete = delegate { };
private int dataItemCurrentlyLoadingIndex;
public DataLoader(string idCode)
{
IdCode = idCode;
DataItems = new List<DataItem>();
dataItemCurrentlyLoadingIndex = -1;
}
public void RegisterText(string idCode, string absoluteSourceUrl)
{
DataItem dataItem = new DataItem
{
IdCode = idCode,
AbsoluteSourceUrl = absoluteSourceUrl,
Kind = DataItemKind.Text
};
DataItems.Add(dataItem);
}
public void BeginLoading()
{
LoadNext();
}
private void LoadNext()
{
dataItemCurrentlyLoadingIndex++;
if (dataItemCurrentlyLoadingIndex < DataItems.Count())
{
DataItem dataItem = DataItems[dataItemCurrentlyLoadingIndex];
Debug.WriteLine("loading " + dataItem.IdCode + "...");
LoadNext();
}
else
{
OnLoadingComplete(this, null); //EXECUTION GETS HERE
}
}
}
public class DataItem
{
public string IdCode { get; set; }
public string AbsoluteSourceUrl { get; set; }
public DataItemKind Kind { get; set; }
public object DataObject { get; set; }
}
public enum DataItemKind
{
Text,
Image
}
public class DataLoaderArgs : EventArgs
{
public string Message { get; set; }
public DataItem DataItem { get; set; }
public DataLoaderArgs(string message, DataItem dataItem)
{
Message = message;
DataItem = dataItem;
}
}
}
