我正在尝试使用异步/等待.NET功能进行Oracle查询.结果集相当大,大概需要5-10秒才能回来. Window_Loaded挂起了UI线程,本质上我想使用async / wait在后台执行查询,然后用结果更新dataview.
那么这是Oracle驱动程序问题还是代码错误？例如.这里的东西是同步进行的,而不是异步的吗？我使用最新的Oracle.ManagedDataAccess我可以从Oracle的网站获得.
async Task<DataTable> AccessOracleAsync()
{
DataTable dt;
using(OracleConnection conn = new OracleConnection(ConfigurationManager.ConnectionStrings["connStr"].ConnectionString))
using (OracleCommand cmd = new OracleCommand(@"SELECT * FROM myTbl",conn))
{
await conn.OpenAsync();
using (var reader = await cmd.ExecuteReaderAsync())
{
dt = new DataTable();
dt.Load(reader);
}
}
return dt;
}
private async void Window_Loaded(object sender,RoutedEventArgs e)
{
await AccessOracleAsync();
}
我尝试过这个,但是它仍然是僵局的UI：
async Task<DataView> AccessOracleAsync()
{
DataTable dt;
using (OracleConnection conn = new OracleConnection(ConfigurationManager.ConnectionStrings["connStr"].ConnectionString))
using (OracleCommand cmd = new OracleCommand(@"SELECT * FROM myTbl",conn))
{
await conn.OpenAsync().ConfigureAwait(false);
using (DbDataReader reader = await cmd.ExecuteReaderAsync().ConfigureAwait(false))
{
dt = new DataTable();
await Task.Run(() => dt.Load(reader)).ConfigureAwait(false);
}
}
return dt.AsDataView();
}
private async void Window_Loaded(object sender,RoutedEventArgs e)
{
Data1.ItemsSource = await AccessOracleAsync();
}
所以最后,我把方法改成了这样的东西,使它不会死锁.看来我有正确的想法,只是Oracle Managed库同步地实现了Async方法(仅符合接口).
private async Task<DataView> AccessOracleAsync()
{
DataTable dt = new DataTable();
using (OracleConnection conn = new OracleConnection(ConfigurationManager.ConnectionStrings["connStr"].ConnectionString))
using (OracleCommand cmd = new OracleCommand(@"SELECT * myTbl",conn))
{
await Task.Run(() =>
{
conn.Open();
using (DbDataReader reader = cmd.ExecuteReader())
{
dt.Load(reader);
}
}).ConfigureAwait(false);
}
return dt.AsDataView();
}
