学步园

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。

using (IsolatedStorageFile isolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication())
                {
                    logPath = Path.Combine(lowerAppName, eventLogFileName);

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

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

                            streamWriter.WriteLine("Event Log：");

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

                            writeFileStream.Dispose();
                        }
                    }
                }