private void button1_Click(object sender, EventArgs e)
        {
            #region//生成SQL 

                #region//生成where条件字符串
                strSql.Append("select * from view_house where ");


                if (strMidle.IndexOf("house_companyName")!=-1)
                {
                    if (strWhere != string.Empty)
                    {
                        strWhere += "and " + "物业名称 like '%" + this.txtName.Text.Trim().ToString() + "%'" ;
                    }
                    else
                    {
                        strWhere += "物业名称 like '%" + this.txtName.Text.Trim().ToString() + "%'";
                    }
                    strMidle=strMidle.Replace("house_companyName", "#");
                 
                }
                if (strMidle.IndexOf("huose_typeID")!= -1)
                {
                    if (strWhere != string.Empty)
                    {
                        strWhere += "and " + "类型='" + this.cboXing.Text.ToString() + "'" ;
                    }
                    else
                    {
                        strWhere += "类型='" + this.cboXing.Text.ToString() + "'" ;
                    }
                    strMidle=strMidle.Replace("huose_typeID", "#");
这段有一些地方看不懂,还有
try
                {
                    string strS = strWhere.Substring(strWhere.Length - 4);
                    if (strS.Trim() == "and")
                    {
                        strWhere = strWhere.Substring(0, strWhere.Length - 4);//去掉尾and
                    }
                }
                catch { return; }
这段也不懂
麻烦小科老师能详细点的给我讲解一下,谢谢