基于C#实现文字转语音功能

        /// <summary>
        /// 试听
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnlisten_click(object sender, eventargs e)
        {
            string text = textbox1.text;
            rate = this.cbxrate.selectedindex;

            if (text.trim().length == 0)
            {
                messagebox.show("不能阅读空内容!", "错误提示");
                return;
            }

            if (btnlisten.text == "语音试听")
            {
                speech = new speechsynthesizer();
                new thread(speak).start();
                btnlisten.text = "停止试听";
            }
            else if (btnlisten.text == "停止试听")
            {
                speech.speakasynccancelall();//停止阅读
                btnlisten.text = "语音试听";
            }
        }

        private void speak()
        {
            promptbuilder builder = getbuiltprompt(this.textbox1.text.tostring().trim());
            speech.rate = rate;
            speech.selectvoice("microsoft huihui desktop");//设置播音员（中文）
            speech.volume = value;
            speech.speakasync(builder);//语音阅读方法
            speech.speakcompleted += speech_speakcompleted;//绑定事件
        }
        
        private promptbuilder getbuiltprompt(string keywords)
        {
            //from http://msdn.microsoft.com/msdnmag/issues/06/01/speechinwindowsvista/ 
            //this prompt is quite complicated
            //so i'm going to build it first, and then render it.
            promptbuilder myprompt = new promptbuilder();

            //start the main speaking style
            promptstyle mainstyle = new promptstyle();
            mainstyle.rate = promptrate.notset;
            mainstyle.volume = promptvolume.medium;
            // mainstyle.emphasis=promptemphasis.reduced;
            myprompt.startstyle(mainstyle);
            convert(myprompt, keywords);
            myprompt.endstyle();
            return myprompt;
        }

 		/// <summary>
        /// 转义关键字
        /// </summary>
        private void convert(promptbuilder myprompt, string keywords)
        {
            //判断是否存在要转换的关键字
            dictionary<int, string> convertcharacter = new dictionary<int, string>();
            var kv_index = keywords.indexof("kv");
            var sf6_index = keywords.indexof("sf6");
            var point_index = keywords.indexof(".");
            if (kv_index > -1)
            {
                convertcharacter.add(kv_index, "kv");
            }
            if (sf6_index > -1)
            {
                convertcharacter.add(sf6_index, "sf6");
            }
            if (point_index > -1)
            {
                convertcharacter.add(point_index, ".");
            }
            convertarray(convertcharacter, myprompt, keywords);
        }
        
		/// <summary>
        /// 转义关键字
        /// </summary>
        private void convertarray(dictionary<int, string> convertcharacter, promptbuilder myprompt, string devicename)
        { 
            string r = @"[0-9]+";
            regex reg = new regex(r, regexoptions.ignorecase | regexoptions.singleline);//2秒后超时
            matchcollection mc = reg.matches(devicename);//设定要查找的字符串 

            //按关键字升序排列
            convertcharacter = convertcharacter.orderby(t => t.key).todictionary(p => p.key, o => o.value);
            int haslen = 0;//记录已经截取的长度
            int splitnum = convertcharacter.count;//要拆分的段数

            //针对有需要转换的地方做特殊处理
            if (splitnum > 0)
            {
                for (var i = 0; i < splitnum; i++)
                {
                    var startindex = convertcharacter.elementat(i).key;//关键字开始的索引
                    var keyvalue = convertcharacter.elementat(i).value.tolower();//关键字
                    var keylen = keyvalue.length;//关键字对应的长度 

                    //先把关键字前面的追加到标题
                    myprompt.appendtext(devicename.substring(haslen, startindex - haslen)); 
                    haslen = startindex + keylen;//留做截取不是关键字的长度 
                    //判断关键字的类型，确定转换方式
                    if (keyvalue == "kv")
                    {
                        myprompt.appendssmlmarkup("<say-as interpret-as = \"kv\">千伏</say-as>");
                    }
                    else if (keyvalue == "sf6")
                    {
                        myprompt.appendtextwithalias("sf6", "六氟化硫");
                    }
                    else if (keyvalue == "-")
                    {
                        myprompt.appendtextwithhint("-", sayas.numbercardinal);
                    }
                    else if (keyvalue == ".")
                    {
                        myprompt.appendtextwithalias(".", "点");
                    }  
                    //如果循环到最后一个关键字，再把最后一个关键字后边的数追加上
                    if (i == splitnum - 1)
                    {
                        myprompt.appendtext(devicename.substring(haslen));
                    }
                } 
            }
            else
            {
                myprompt.appendtext(devicename);
            }
        }

  		/// <summary>
        /// 语音阅读完成触发此事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void speech_speakcompleted(object sender, speakcompletedeventargs e)
        {
            //改变按钮文本值
            changebtntext changebtntext = changetext;
            this.btnlisten.begininvoke(changebtntext);
        }
        
        /// <summary>
        /// 委托方法，改变按钮值
        /// </summary>
        public void changetext()
        {
            btnlisten.text = "语音试听";
        }