CloudTable ExecuteQuery异步

Question

是否可以异步运行ExecuteQuery？

考虑以下代码：

public virtual MyEntity MyMethod(string parm1, string parm2)
{
     string queryString = TableQuery.CombineFilters(TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.Equal, parm1),
                                                    TableOperators.And,
                                                    TableQuery.GenerateFilterCondition("RowKey", QueryComparisons.Equal, parm2));
     TableQuery<MyEntity> query = new TableQuery<MyEntity>().Where(queryString);

     return TenantTnsTable.ExecuteQuery(query).ToList().FirstOrDefault();
}

有没有可能使这成为异步方法，并在ExecuteQuery调用中使用await？

Answer 1

试试Task.Run。您应该能够异步运行任何非异步代码，然后对结果执行await。

Answer 2

你可以用Task.Factory.FromAsync包装旧式的回调函数。例如：

public static Task<TableQuerySegment<T>> ExecuteQueryAsync<T>(
        this CloudTable table,
        TableQuery<T> query,
        TableContinuationToken token,
        CancellationToken ct = default(CancellationToken))
        where T : ITableEntity, new()
    {
        ICancellableAsyncResult ar = table.BeginExecuteQuerySegmented(query, token, null, null);
        ct.Register(ar.Cancel);

        return Task.Factory.FromAsync<TableQuerySegment<T>>(ar, table.EndExecuteQuerySegmented<T>);
    }