c# – 如何等待await / async方法完成

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c# – 如何等待await / async方法完成

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我有以下Async方法：

private async void ProcessSearch()

{

// get catalogs on first search

if (_invoiceTypes == null && _invoiceAccounts == null)

{

var confWcf = new Data.ConfigurationWCF();

_invoiceTypes = await confWcf.GetInvoiceTypesAsync(MainForm.State.Entity);

_invoiceAccounts = await confWcf.GetInvoiceAccountsAsync(MainForm.State.Entity);

confWcf.Dispose();

}

var seekWcf = new DataSeekWCF();

_ds = await seekWcf.SearchInvoiceAdminAsync(new Guid(cboEmployer.Value.ToString()), new Guid(cboGroup.Value.ToString()), txtSearchInvoiceNumber.Text, chkSearchLike.Checked, txtSearchFolio.Text, Convert.ToInt32(txtYear.Value));

seekWcf.Dispose();

if (_ds != null)

{

SetupInvoiceGrid();

}

在_invoiceTypes,_invoiceAccounts和_ds完成之前,我不想执行SetupInvoiceGrid.

任何线索？我做得对吗？我应该使用Task而不是等待吗？

我已经想出了这个代码似乎正在工作,看起来很好,但我不知道它是否正确：

private void btnSearch_Click(object sender, EventArgs e)

{

lock (lockObj)

{

if (_isBusy)

return;

else

_isBusy = true;

}

ShowPleaseWait(Translate("Searching data. Please wait..."));

if (_invoiceTypes == null && _invoiceAccounts == null)

{

var t = GetCatalogs();

t.ContinueWith(t2 =>

{

if (t.IsCompleted) ProcessSearch();

});

}

else

{

ProcessSearch();

}

private async Task GetCatalogs()

{

// get catalogs on first search

Data.ConfigurationWCF confWcf = new Data.ConfigurationWCF();

var task1 = confWcf.GetInvoiceTypesAsync(1);

var task2 = confWcf.GetInvoiceAccountsAsync(1);

confWcf.Dispose();

await Task.WhenAll(task1, task2);

_invoiceTypes = task1.Result;

_invoiceAccounts = task2.Result;

if (_invoiceTypes != null)

{

cboInvoiceType.DataSource = _invoiceTypes.Tables["invoice_types"];

cboInvoiceType.DisplayMember = "description";

cboInvoiceType.ValueMember = "code";

}

private async void ProcessSearch()

{

var seekWcf = new Data.SeekWCF();

seekWcf.Dispose();

if (_ds != null)

{

SetupInvoiceGrid();

}

HidePleaseWait();

}

最佳答案

我回答了关于如何处理ProcessSearchAsync本身 here的完成的原始(？)问题.

要并行运行任务(如评论中所述),这里修改了代码,因为invoiceTypes == null和_invoiceAccounts == null检查,它会变得有点复杂.注意下面实现检查的方式稍微改变了逻辑(之前只有当_invoiceTypes和_invoiceAccounts都为null时才会调用WCF – 如果只有其中一个为null,那么它是什么？)：

private async Task ProcessSearchAsync()

{

Data.ConfigurationWCF confWcf = new Data.ConfigurationWCF();

Task</*typeof _invoiceTypes*/> t1;

Task</*typeof _invoiceAccounts*/> t2;

if (_invoiceTypes == null)

t1 = confWcf.GetInvoiceTypesAsync(MainForm.State.Entity);

else

{

var tsc1 = new TaskCompletionSource</*typeof _invoiceTypes*/>();

t1 = tsc1.Task;

tsc1.SetResult(_invoiceTypes);

}

if ( _invoiceAccounts == null )

t2 = confWcf.GetInvoiceAccountsAsync(MainForm.State.Entity);

else

{

var tsc2 = new TaskCompletionSource</*typeof _invoiceAccounts*/>();

t2 = tsc2.Task;

tsc2.SetResult(_invoiceAccounts);

}

DataSeekWCF seekWcf = new DataSeekWCF();

Task</*typeof _ds*/> t3 = seekWcf.SearchInvoiceAdminAsync(new Guid(cboEmployer.Value.ToString()), new Guid(cboGroup.Value.ToString()), txtSearchInvoiceNumber.Text, chkSearchLike.Checked, txtSearchFolio.Text, Convert.ToInt32(txtYear.Value));

await Task.WhenAll(new Task[] {t1, t2, t3});

_invoiceTypes = t1.Result;

_invoiceAccounts = t2.Result;

ds = t3.Result;

if (_ds != null)

{

SetupInvoiceGrid();

}

confWcf.Dispose();

seekWcf.Dispose();

}

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