在网上看到很多关于如何捕获异步编程中的异常的方法，有很多写的都不是很明确，而且很多写的方法都不正确。异步编程中的异常捕获和同步编程的异常捕获其实不太一样，但也非常简单。
使用WhenAll执行任务，代码如下：
public async Task Start()
{
Task taskResult = null;
Task t1 = null;
Task t2 = null;
Task t3 = null;
try
{
t1 = GetData1();
t2 = GetData2();
t3 = t1.ContinueWith((rst) =>
{
//Console.WriteLine("hahaha!" + rst.Result);
throw new Exception("Exception3");
});
await (taskResult = Task.WhenAll(t1, t2,t3));
Console.WriteLine("Complate1!");
Console.WriteLine("t1:" + t1.Result + ";t2:" + t2.Result);
Console.WriteLine("Complate2!");
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
if (taskResult != null && taskResult.IsFaulted)
{
foreach (var oneEx in taskResult.Exception.InnerExceptions)
{
Console.WriteLine(oneEx.Message);
}
}
}
}
private async Task GetData1()
{
await Task.Delay(1000);
Console.WriteLine("调用GetData1");
await GetData4();
throw new Exception("Exception1");
//return "123";
}
private async Task GetData2()
{
await Task.Delay(2000);
Console.WriteLine("调用GetData2");
throw new Exception("Exception2");
//return "456";
}
private async Task GetData4()
{
await Task.Delay(1000);
Console.WriteLine("调用GetData4");
throw new Exception("Exception4");
//return "123";
}
使用 WaitAll执行方法时，代码如下：
public async Task Start()
{
Task t1 = null;
Task t2 = null;
Task t3 = null;
try
{
t1 = GetData1();
t2 = GetData2();
t3 = t1.ContinueWith((rst) =>
{
//Console.WriteLine("hahaha!" + rst.Result);
throw new Exception("Exception3");
});
Task.WaitAll(t1, t2, t3);
Console.WriteLine("Complate1!");
Console.WriteLine("t1:" + t1.Result + ";t2:" + t2.Result);
Console.WriteLine("Complate2!");
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
if (t1 != null && t1.IsFaulted)
{
foreach (var oneEx in t1.Exception.InnerExceptions)
{
Console.WriteLine(oneEx.Message);
}
}
if (t2 != null && t2.IsFaulted)
{
foreach (var oneEx in t2.Exception.InnerExceptions)
{
Console.WriteLine(oneEx.Message);
}
}
if (t3 != null && t3.IsFaulted)
{
foreach (var oneEx in t3.Exception.InnerExceptions)
{
Console.WriteLine(oneEx.Message);
}
}
}
}
