我正在看关于可序列化dto的文章c# -数据传输对象。
这篇文章包含了下面这段代码:
public static string SerializeDTO(DTO dto) {
try {
XmlSerializer xmlSer = new XmlSerializer(dto.GetType());
StringWriter sWriter = new StringWriter();
xmlSer.Serialize(sWriter, dto);
return sWriter.ToString();
}
catch(Exception ex) {
throw ex;
}
}
文章的其余部分看起来理智而合理(对于新手来说)，但是try-catch-throw抛出了一个WtfException…这不完全等同于不处理异常吗?
结论:
public static string SerializeDTO(DTO dto) {
XmlSerializer xmlSer = new XmlSerializer(dto.GetType());
StringWriter sWriter = new StringWriter();
xmlSer.Serialize(sWriter, dto);
return sWriter.ToString();
}
还是我错过了c#中错误处理的一些基本内容?它与Java非常相似(减去受控异常)，不是吗?．.． 也就是说，它们都改进了c++。
堆栈溢出问题重新抛出无参数catch和什么都不做之间的区别?这似乎支持了我的观点，试着接球是不行的。
编辑:
只是为了给将来找到这条线索的人做个总结…
不
try {
// Do stuff that might throw an exception
}
catch (Exception e) {
throw e; // This destroys the strack trace information!
}
堆栈跟踪信息对于确定问题的根本原因至关重要!
DO
try {
// Do stuff that might throw an exception
}
catch (SqlException e) {
// Log it
if (e.ErrorCode != NO_ROW_ERROR) { // filter out NoDataFound.
// Do special cleanup, like maybe closing the "dirty" database connection.
throw; // This preserves the stack trace
}
}
catch (IOException e) {
// Log it
throw;
}
catch (Exception e) {
// Log it
throw new DAOException("Excrement occurred", e); // wrapped & chained exceptions (just like java).
}
finally {
// Normal clean goes here (like closing open files).
}
在不太特定的异常之前捕获更特定的异常(就像Java一样)。
引用:
MSDN -异常处理
MSDN - try-catch (c#参考)
当您没有特定的代码来处理当前异常时，或者当您有处理特定错误情况的逻辑但想要跳过所有其他情况时，通过throw重新抛出异常非常有用。
例子:
string numberText = "";
try
{
Console.Write("Enter an integer: ");
numberText = Console.ReadLine();
var result = int.Parse(numberText);
Console.WriteLine("You entered {0}", result);
}
catch (FormatException)
{
if (numberText.ToLowerInvariant() == "nothing")
{
Console.WriteLine("Please, please don't be lazy and enter a valid number next time.");
}
else
{
throw;
}
}
finally
{
Console.WriteLine("Freed some resources.");
}
Console.ReadKey();
然而，还有另一种方法，在catch块中使用条件子句:
string numberText = "";
try
{
Console.Write("Enter an integer: ");
numberText = Console.ReadLine();
var result = int.Parse(numberText);
Console.WriteLine("You entered {0}", result);
}
catch (FormatException) when (numberText.ToLowerInvariant() == "nothing")
{
Console.WriteLine("Please, please don't be lazy and enter a valid number next time.");
}
finally
{
Console.WriteLine("Freed some resources.");
}
Console.ReadKey();
这种机制比重新抛出异常更有效，因为
的。net运行时不需要重新构建异常对象
然后再扔出去。
当您没有特定的代码来处理当前异常时，或者当您有处理特定错误情况的逻辑但想要跳过所有其他情况时，通过throw重新抛出异常非常有用。
例子:
string numberText = "";
try
{
Console.Write("Enter an integer: ");
numberText = Console.ReadLine();
var result = int.Parse(numberText);
Console.WriteLine("You entered {0}", result);
}
catch (FormatException)
{
if (numberText.ToLowerInvariant() == "nothing")
{
Console.WriteLine("Please, please don't be lazy and enter a valid number next time.");
}
else
{
throw;
}
}
finally
{
Console.WriteLine("Freed some resources.");
}
Console.ReadKey();
然而，还有另一种方法，在catch块中使用条件子句:
string numberText = "";
try
{
Console.Write("Enter an integer: ");
numberText = Console.ReadLine();
var result = int.Parse(numberText);
Console.WriteLine("You entered {0}", result);
}
catch (FormatException) when (numberText.ToLowerInvariant() == "nothing")
{
Console.WriteLine("Please, please don't be lazy and enter a valid number next time.");
}
finally
{
Console.WriteLine("Freed some resources.");
}
Console.ReadKey();
这种机制比重新抛出异常更有效，因为
的。net运行时不需要重新构建异常对象
然后再扔出去。
不要这样做，
try
{
...
}
catch(Exception ex)
{
throw ex;
}
您将丢失堆栈跟踪信息…
无论做什么,
try { ... }
catch { throw; }
OR
try { ... }
catch (Exception ex)
{
throw new Exception("My Custom Error Message", ex);
}
您可能想要重新抛出的原因之一是，如果您正在处理不同的异常，对于
如。
try
{
...
}
catch(SQLException sex)
{
//Do Custom Logging
//Don't throw exception - swallow it here
}
catch(OtherException oex)
{
//Do something else
throw new WrappedException("Other Exception occured");
}
catch
{
System.Diagnostics.Debug.WriteLine("Eeep! an error, not to worry, will be handled higher up the call stack");
throw; //Chuck everything else back up the stack
}
