请问在VS community2017中编制通用版如何发音合成？

[hxzgy]

我参考一些8.1的资料，用VB开发，想把字符串发音出来，始终说格式不对，请大师们指点一下！谢谢！
下面是我写的：
Dim ss As String
ss = "Hello"

Dim myPlay As New MediaElement
Dim synth As New SpeechSynthesizer()
Dim mystream As SpeechSynthesisStream
mystream = synth.SynthesizeTextToStreamAsync(ss) '这句执行不下去
myMediaElement.AutoPlay = True
myMediaElement.SetSource(mystream, mystream.ContentType)
myMediaElement.Play()

[hxzgy]

我想把“Hello"发音读出来

[48303354]

Dim synth As New SpeechSynthesizer() synth.SpeakAsync(ss) 'ss为要读出来的字符 这样不可以吗？VB.NET是可以的