Application.ThreadException
在抛出异常并在事件处理程序中捕获它们时,我看到了一些奇怪的行为。
基本上下面示例中发生的事情是DoWork
在BackgroundWorker
. 事件RunWorkerCompleted
处理程序以原始异常作为内部异常重新引发新异常。
为什么内部异常出现在ThreadException
事件处理程序中而不是实际异常被抛出?如果我没有在RunWorkerCompleted
事件处理程序中提供内部异常,则会显示正确的异常。
using System;
using System.Windows.Forms;
using System.ComponentModel;
namespace WierdExceptionApp
{
class WierdExceptionForm : Form
{
BackgroundWorker worker = new BackgroundWorker();
public WierdExceptionForm()
{
worker.DoWork += new DoWorkEventHandler(worker_DoWork);
worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
worker.RunWorkerAsync();
}
void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
if (e.Error != null)
{
throw new Exception("worker_RunWorkerCompleted", e.Error);
}
}
void worker_DoWork(object sender, DoWorkEventArgs e)
{
throw new Exception("worker_DoWork");
}
[STAThread]
static void Main()
{
Application.ThreadException += new System.Threading.ThreadExceptionEventHandler(Application_ThreadException);
Application.Run(new WierdExceptionForm());
}
static void Application_ThreadException(object sender, System.Threading.ThreadExceptionEventArgs e)
{
MessageBox.Show(e.Exception.Message);
}
}
}