How to use Java-style throws keyword in C#?
In Java, you must either handle an exception or mark the method as one that may throw it using the throws
keyword.
C# does not have this keyword or an equivalent one, as in C#, if you don't handle an exception, it will bubble up, until caught or if not caught it will terminate the program.
If you want to handle it then re-throw you can do the following:
try
{
// code that throws an exception
}
catch(ArgumentNullException ex)
{
// code that handles the exception
throw;
}
The op is asking about the C# equivalent of Java's throws
clause - not the throw
keyword. This is used in method signatures in Java to indicate a checked exception can be thrown.
In C#, there is no direct equivalent of a Java checked exception. C# has no equivalent method signature clause.
// Java - need to have throws clause if IOException not handled
public void readFile() throws java.io.IOException {
...not explicitly handling java.io.IOException...
}
translates to
// C# - no equivalent of throws clause exceptions are unchecked
public void ReadFile()
{
...not explicitly handling System.IO.IOException...
}
Yes this is an old thread, however I frequently find old threads when I am googling answers so I figured I would add something useful that I have found.
If you are using Visual Studio 2012 there is a built in tool that can be used to allow for an IDE level "throws" equivalent.
If you use XML Documentation Comments, as mentioned above, then you can use the <exception> tag to specify the type of exception thrown by the method or class as well as information on when or why it is thrown.
example:
/// <summary>This method throws an exception.</summary>
/// <param name="myPath">A path to a directory that will be zipped.</param>
/// <exception cref="IOException">This exception is thrown if the archive already exists</exception>
public void FooThrowsAnException (string myPath)
{
// This will throw an IO exception
ZipFile.CreateFromDirectory(myPath);
}