DotNetSpeech.dll编写语音朗读没办法暂停

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using DotNetSpeech;
namespace Web
{
public partial class WebForm2 : System.Web.UI.Page
{
DotNetSpeech.SpeechVoiceSpeakFlags SpFlags =DotNetSpeech.SpeechVoiceSpeakFlags.SVSFlagsAsync;
DotNetSpeech.SpVoice Voice = new SpVoice();
protected void Page_Load(object sender, EventArgs e)
{

}
protected void Button1_Click(object sender, EventArgs e)
{
try
{
Voice.Speak(this.Label1.Text, SpFlags); //读取Label1中的文字
}
catch
{
}
}
protected void Button2_Click(object sender, EventArgs e)
{
Voice.Pause();
}

}
}
能够读文本中的内容，但是不能停止，求帮助

我这里可以，是不是你输入的字符太少，多输点 看效果