Operation not permitted on IsolatedStorageFileStream 解决方法

在做Windows Phone开发时，应该都遇到过 Operation not permitted on IsolatedSotrageFileStream异常。比如，刚刚Create的File，马上去读就会遇到这样的问题。问题在于IsolatedStorageFile.CreateFile返回的是一个IsolatedStorageFileStream, 而在IsolatedStorageFile.OpenFile时又会创建另一个IsolatedStorageFileStream而前者并没有释放, 因此就会出现这样的问题。正确的用法如下：

string filePath = "log.txt";

                if (!isolatedStorageFile.FileExists(filePath))
                {
                    using (IsolatedStorageFileStream createFileStream = isolatedStorageFile.CreateFile(filePath))
                    {
                        createFileStream.Close();
                    }

                    using (
                        IsolatedStorageFileStream writeFileStream = isolatedStorageFile.OpenFile(filePath,
                                                                                                 FileMode.OpenOrCreate,
                                                                                                 FileAccess
                                                                                                     .ReadWrite,
                                                                                                 FileShare.ReadWrite)
                        )
                    using (var streamWriter = new StreamWriter(writeFileStream))
                    {

                        streamWriter.WriteLine("Event Log：");

                        streamWriter.Close();
                        writeFileStream.Close();

                        writeFileStream.Dispose();
                    }
                }
            }