Windows Workflow Foundation-在工作流中的不同活动之间传递自定义变量

Question

I am passing a custom variable type from one action to another action in a workflow. Here is the definition of the custom object

       public class ConfigDatabase
        {
            public string Name;
            public string Host;
            public string Port;
            public string Instance;
            public string User;
            public string Password;
        }

        public class ConfigDatabases
        {
            public string DatabaseToUse;
            public List<ConfigDatabase> DatabaseList;

            public ConfigDatabases()
            {
                DatabaseList = new List<ConfigDatabase>();
            }
        }

        public class ConfigEnvironment
        {
            public ConfigDatabases EnvironmentConfigDatabase;

            public ConfigEnvironment()
            {
                EnvironmentConfigDatabase = new ConfigDatabases();
            }

            public ConfigDatabase ReturnDatabaseInfo()
            {
                ConfigDatabase ConfigDatabaseInfo = new ConfigDatabase();
                for (int Count1 = 0; Count1 < EnvironmentConfigDatabase.DatabaseList.Count; Count1++)
                {
                    if (EnvironmentConfigDatabase.DatabaseList[Count1].Name == EnvironmentConfigDatabase.DatabaseToUse)
                    {
                        ConfigDatabaseInfo = EnvironmentConfigDatabase.DatabaseList[Count1];
                        return ConfigDatabaseInfo;
                    }
                }
                return ConfigDatabaseInfo;
            }

            public string GetDatabaseConnectionString()
            {
                ConfigDatabase DatabaseInfo = ReturnDatabaseInfo();
                string ConnectionString = "Data Source=(description=(address=(protocol=tcp)(host=" + DatabaseInfo.Host + ")(port=" + DatabaseInfo.Port + "))(connect_data=(sid=" + DatabaseInfo.Instance + ")));User ID=" + DatabaseInfo.User + ";Password=" + DatabaseInfo.Password + ";";
                return ConnectionString;
            }
        }

During the first step of the action, it will run the following code to load the config data from a file and store in an object (ConfigEnvironment) that is returned in function Execute

public sealed class InitializeEnvironment : CodeActivity<ConfigEnvironment>
{
    // Define an activity input argument of type string
    public InArgument<string> EnvironmentFileLocation { get; set; }

    // If your activity returns a value, derive from CodeActivity<TResult>
    // and return the value from the Execute method.
    protected override ConfigEnvironment Execute(CodeActivityContext context)
    {
        // Obtain the runtime value of the Text input argument
        string EnvironmentFile = context.GetValue(this.EnvironmentFileLocation);
        EnvironmentConfigInitialization EnvironmentInitialize = new EnvironmentConfigInitialization(EnvironmentFile);
        ConfigEnvironment EnvironmentDetail = EnvironmentInitialize.LoadData();
        return EnvironmentDetail;
    }
}

In the subsequent activity in the workflow, I would like to obtain the data stored in this object. However, the following code will have a compile error as EnvironmentDetail object could not find the function GetDatabaseConnectionString.

public sealed class ExecuteSQL : CodeActivity<DataRowCollection>
{
    // Define an activity input argument of type string
    public InArgument<string> SQLScript { get; set; }
    public InArgument<ConfigEnvironment> EnvironmentDetail { get; set; }

    // If your activity returns a value, derive from CodeActivity<TResult>
    // and return the value from the Execute method.
    protected override DataRowCollection Execute(CodeActivityContext context)
    {

        string connectionString4 = EnvironmentDetail.GetDatabaseConnectionString(); //This create a compile error

}

}

The compile warning is the following 'System.Activities.InArgument' does not contain a definition for 'GetDatabaseConnectionString' and no extension method 'GetDatabaseConnectionString' accepting a first argument of type 'System.Activities.InArgument' could be found (are you missing a using directive or an assembly reference?)

Answer 1

As it turns out, EnvironmentDetail is of Type InArgument (or InArgument<ConfigEnvironment> ) but not of Type ConfigEnvironment You need to do a context.Get<ConfigEnvironment>() to get a variable of Type ConfigEnvironment .

Let me know if this solves your problem or if there's something else still amiss ;-)