azure - 悲伤、愤怒和绝望设置 Azure 存储

Question

我正在尝试在本地使用 Azure 存储。我有一个名为 ExpenseDataSource 的数据源类:

public class ExpenseDataSource
{
    private static CloudStorageAccount storageAccount;
    private ExpenseTableContext context;

    static ExpenseDataSource()
    {
        //CloudStorageAccount.SetConfigurationSettingPublisher(
        //    (configName, configSettingPublisher) =>
        //    {
        //        string connectionString = RoleEnvironment.GetConfigurationSettingValue(configName);
        //        configSettingPublisher(connectionString);
        //    }
        //);

        storageAccount = CloudStorageAccount.FromConfigurationSetting("DataConnectionString");

        CloudTableClient.CreateTablesFromModel(typeof(ExpenseTableContext), storageAccount.TableEndpoint.AbsoluteUri, storageAccount.Credentials);
    }

    public ExpenseDataSource()
    {
        context = new ExpenseTableContext(storageAccount.TableEndpoint.AbsoluteUri, storageAccount.Credentials);
        context.RetryPolicy = RetryPolicies.Retry(3, TimeSpan.FromSeconds(1));
    }

    public IEnumerable<ExpenseInfo> Select()
    {
        var results = from g in context.Expenses
                      where g.PartitionKey == "Expense"
                      select g;

        return results;
    }
    // ...
}

(我是 Azure 新手，因此该类在很多方面可能不是最佳的。)

当我尝试创建 ExpenseDataSource 类型的对象时，出现以下异常:

System.TypeInitializationException: The type initializer for 'WebRole1.ExpenseDataSource' threw an exception. ---> System.InvalidOperationException: SetConfigurationSettingPublisher needs to be called before FromConfigurationSetting can be used
   at Microsoft.WindowsAzure.CloudStorageAccount.FromConfigurationSetting(String settingName)
   at WebRole1.ExpenseDataSource..cctor() in [ ... ]
   --- End of inner exception stack trace ---
   at WebRole1.ExpenseDataSource..ctor()
   at WebRole1.ExpenseService.WebRole1.IExpenseService.GetExpenses() in [ ... ]

但是，这很奇怪，因为已经调用了 SetConfiguationSettingPublisher:

public class WebRole : RoleEntryPoint
{
    public override bool OnStart()
    {
        DiagnosticMonitor.Start("DiagnosticsConnectionString");

        // For information on handling configuration changes
        // see the MSDN topic at http://go.microsoft.com/fwlink/?LinkId=166357.
        RoleEnvironment.Changing += RoleEnvironmentChanging;

        CloudStorageAccount.SetConfigurationSettingPublisher(
            (configName, configSettingPublisher) =>
            {
                string connectionString = RoleEnvironment.GetConfigurationSettingValue(configName);
                configSettingPublisher(connectionString);
            }
        );

        return base.OnStart();
    }
    // ...
 }

当我开始调试时，我能够在此处命中断点。

我在这里做错了什么？

更新:我想也许我启动了 dev Fabric 和 ASP.NET localhost，所以我杀死了它们，启动了 dev fabic，然后启动了 ASP 项目。仍然没有运气 - 发生同样的错误。

更新 2:我将 OnStart() 更改为此，但它仍然不起作用:

  public override bool OnStart()  
    {
        DiagnosticMonitor.Start("DiagnosticsConnectionString");

        // For information on handling configuration changes
        // see the MSDN topic at http://go.microsoft.com/fwlink/?LinkId=166357.
        RoleEnvironment.Changing += RoleEnvironmentChanging;

        #region Setup CloudStorageAccount Configuration Setting Publisher

        // This code sets up a handler to update CloudStorageAccount instances when their corresponding
        // configuration settings change in the service configuration file.
        CloudStorageAccount.SetConfigurationSettingPublisher((configName, configSetter) =>
        {
            // Provide the configSetter with the initial value
            configSetter(RoleEnvironment.GetConfigurationSettingValue(configName));

            RoleEnvironment.Changed += (sender, arg) =>
            {
                if (arg.Changes.OfType<RoleEnvironmentConfigurationSettingChange>()
                    .Any((change) => (change.ConfigurationSettingName == configName)))
                {
                    // The corresponding configuration setting has changed, propagate the value
                    if (!configSetter(RoleEnvironment.GetConfigurationSettingValue(configName)))
                    {
                        // In this case, the change to the storage account credentials in the
                        // service configuration is significant enough that the role needs to be
                        // recycled in order to use the latest settings. (for example, the 
                        // endpoint has changed)
                        RoleEnvironment.RequestRecycle();
                    }
                }
            };
        });
        #endregion

        return base.OnStart();
    }

更新 3:我尝试将“设置 CloudStorageAccount 配置设置发布者”区域放入 ExpenseDataSource 静态初始值设定项中，但出现以下错误:

System.TypeInitializationException: The type initializer for 'WebRole1.ExpenseDataSource' threw an exception. ---> System.Runtime.InteropServices.SEHException: External component has thrown an exception.
   at RoleEnvironmentGetConfigurationSettingValueW(UInt16* , UInt16* , UInt32 , UInt32* )
   at Microsoft.WindowsAzure.ServiceRuntime.Internal.InteropRoleManager.GetConfigurationSetting(String name, String& ret)
   at Microsoft.WindowsAzure.ServiceRuntime.RoleEnvironment.GetConfigurationSettingValue(String configurationSettingName)
   at WebRole1.ExpenseDataSource.<.cctor>b__0(String configName, Func`2 configSetter) in C:\Users\ODP\Documents\Visual Studio 2010\Projects\ExpenseCalc\WebRole1\ExpenseDataSource.cs:line 26
   at Microsoft.WindowsAzure.CloudStorageAccount.StorageAccountConfigurationSetting..ctor(String configurationSettingName)
   at Microsoft.WindowsAzure.CloudStorageAccount.FromConfigurationSetting(String settingName)
   at WebRole1.ExpenseDataSource..cctor() in C:\Users\ODP\Documents\Visual Studio 2010\Projects\ExpenseCalc\WebRole1\ExpenseDataSource.cs:line 47
   --- End of inner exception stack trace ---
   at WebRole1.ExpenseDataSource..ctor()
   at WebRole1.ExpenseService.WebRole1.IExpenseService.GetExpenses() in C:\Users\ODP\Documents\Visual Studio 2010\Projects\ExpenseCalc\WebRole1\ExpenseService.svc.cs:line 18

更新 3:按照 smarx 的建议，我更改了静态初始值设定项:

    static ExpenseDataSource()
    {
        //storageAccount = CloudStorageAccount.FromConfigurationSetting("DataConnectionString");
        storageAccount = CloudStorageAccount.Parse(RoleEnvironment.GetConfigurationSettingValue("DataConnectionString"));

        CloudTableClient.CreateTablesFromModel(typeof(ExpenseTableContext), storageAccount.TableEndpoint.AbsoluteUri, storageAccount.Credentials);
    }

这会导致以下错误:

System.TypeInitializationException: The type initializer for 'WebRole1.ExpenseDataSource' threw an exception. ---> System.Runtime.InteropServices.SEHException: External component has thrown an exception.
   at RoleEnvironmentGetConfigurationSettingValueW(UInt16* , UInt16* , UInt32 , UInt32* )
   at Microsoft.WindowsAzure.ServiceRuntime.Internal.InteropRoleManager.GetConfigurationSetting(String name, String& ret)
   at Microsoft.WindowsAzure.ServiceRuntime.RoleEnvironment.GetConfigurationSettingValue(String configurationSettingName)
   at WebRole1.ExpenseDataSource..cctor() in C:\Users\ODP\Documents\Visual Studio 2010\Projects\ExpenseCalc\WebRole1\ExpenseDataSource.cs:line 20
   --- End of inner exception stack trace ---
   at WebRole1.ExpenseDataSource..ctor()
   at WebRole1.ExpenseService.WebRole1.IExpenseService.GetExpenses() in C:\Users\ODP\Documents\Visual Studio 2010\Projects\ExpenseCalc\WebRole1\ExpenseService.svc.cs:line 18

该错误与上面略有不同。这是否与我实际上没有在开发结构中运行 ASP.NET 的想法有关？

呃。我开始怀念 Google App Engine 存储的简单 get() 和 put() 接口(interface)。

Answer 1

1) 确保您的 WebRole 设置中配置了“DataConnectionString”。

• 在解决方案资源管理器中 --> 在“角色”文件夹下 --> 右键单击​​ |属性 --> 转到“设置”选项卡并单击“添加设置”。输入名称:“DataConnectionString”；类型:“连接字符串”；值:“UseDevelopmentStorage=true”(如果您想要调试和使用本地存储)或者如果您计划迁移到 Azure，请输入您的存储帐户详细信息。

2) (在上面的代码中 - 删除 SetConfigurationSettingPublisher 的注释)。您的代码应如下所示:

CloudStorageAccount.SetConfigurationSettingPublisher((configName, configSetter) =>
{
configSetter(RoleEnvironment.GetConfigurationSettingValue(configName));
});
var storageAccount = CloudStorageAccount.FromConfigurationSetting("DataConnectionString");