问题描述
我有一个旧的API,它会以这种方式切换当前的区域性:
private void ChangeCulture(int lcid)
{
Debug.WriteLine($"[{Thread.CurrentThread.ManagedThreadId}] ChangeCulture Culture Start: {Thread.CurrentThread.CurrentCulture}");
var newCulture = CultureInfo.GetCultureInfo(lcid);
Debug.WriteLine($"[{Thread.CurrentThread.ManagedThreadId}] Changing culture of currentThread to: {newCulture}");
Thread.CurrentThread.CurrentCulture = newCulture;
Thread.CurrentThread.CurrentUICulture = newCulture;
// Old framework compatibility (not important for this example)
CultureInfo.DefaultThreadCurrentCulture = newCulture;
CultureInfo.DefaultThreadCurrentUICulture = newCulture;
Debug.WriteLine($"[{Thread.CurrentThread.ManagedThreadId}] ChangeCulture Culture End: {Thread.CurrentThread.CurrentCulture}");
}
以前,代码是从同步上下文中调用的。但是,由于现在需要从异步上下文中调用代码。就像这里:
private async void Button_Click(object sender,RoutedEventArgs e)
{
Debug.WriteLine($"[{Thread.CurrentThread.ManagedThreadId}]Culture Start: {Thread.CurrentThread.CurrentCulture}");
if (this.currrentLcid == 1031)
{
await Task.Delay(1000);
this.ChangeCulture(1033);
this.currrentLcid = 1033;
}
else
{
await Task.Delay(1000);
this.ChangeCulture(1031);
this.currrentLcid = 1031;
}
Debug.WriteLine($"[{Thread.CurrentThread.ManagedThreadId}]Culture End: {Thread.CurrentThread.CurrentCulture}");
}
输出:
[1]Culture Start: de-DE
[1] ChangeCulture Culture Start: de-DE
[1] Changing culture of currentThread to: en-US
[1] ChangeCulture Culture End: en-US
[1]Culture End: en-US
具有异步执行的文化流。但是它不会在全球范围内回流。如果我打电话:
private void CheckCulture_Click(object sender,RoutedEventArgs e)
{
Debug.WriteLine($"[{Thread.CurrentThread.ManagedThreadId}]CheckCulture_Click: {Thread.CurrentThread.CurrentCulture}");
}
输出:
[1]CheckCulture_Click: de-DE
一切都是MainThread。 (ManagedThreadId = 1)
.NET Framework 4.8
如何在不了解调用上下文的情况下在全球范围内切换当前的文化?
解决方法
在.NET Core中,这些属性实现为AsyncLocal<T>
,简而言之,意味着对它们的任何更新只会影响当前的异步控制流,例如async
方法。
根据要完成的任务,您可以考虑创建并设置自己的静态CultureInfo
属性。
在.NET Framework 4.6和更高版本上,您可以在NoAsyncCurrentCulture
中将true
开关设置为App.config
,以恢复旧的行为:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.8"/>
</startup>
<runtime>
<AppContextSwitchOverrides value="Switch.System.Globalization.NoAsyncCurrentCulture=true"/>
</runtime>
</configuration>
<AppContextSwitchOverrides> element
Retargeting Changes for Migration from .NET Framework 4.5 to 4.6