Delphi中的C#/ Java"Try/Finally/Catch"等效构造

Question

在Delphi中,你如何才能最终使用try,并一起使用？Java/C#等价物看起来像:

try {
    // Open DB connection, start transaction
} catch (Exception e) {
    // Roll back DB transaction
} finally {
    // Close DB connection, commit transaction
}

如果你在Delphi中尝试这个,你可以使用try/finally或try/except; 但从来没有三个在一起.我想代码如下(不编译):

try
    // Open DB connection, start transaction
except on e: Exception do
begin
    // Roll back transaction
end
finally // Compiler error: expected "END" not "finally"
begin
    // Commit transaction
end

Answer 1

在Delphi中,您可以使用以下模式:

// initialize / allocate resource (create objects etc.)
...
try
  try
    // use resource
    ...
  except
    // handle exception
    ...
  end;
finally
  // free resource / cleanup
  ...
end

Answer 2

写

try 
  // allocate resource here
  try 
  finally
    // free resource here
  end;
except
  // handle exception here
end;