SilverLight C#程序 把二进制流转换为文件 并打开文件及exe程序

<Grid>
                                    <Grid.RowDefinitions>
                                        <RowDefinition Height="*"></RowDefinition>
                                        <RowDefinition Height="30"></RowDefinition>
                                    </Grid.RowDefinitions>
                                    <sdk:DataGrid x:Name="gridConAttachmentModel" Grid.Row="0" RowHeight="25" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="#FEFEFE" HeadersVisibility="Column" BorderThickness="0,1,0,0" GridLinesVisibility="All" AutoGenerateColumns="False" FrozenColumnCount="1" AreRowDetailsFrozen="True" 
                                                  ItemsSource="{Binding ConAttachmentModelList}" SelectedItem="{Binding ConAttachmentModel}" IsReadOnly="True">
                                        <sdk:DataGrid.Columns>
                                            <sdk:DataGridTextColumn Header="序号" Binding="{Binding ConAtt_OrderNum,Mode=TwoWay}" IsReadOnly="True" />
                                            <sdk:DataGridTextColumn Header="附件名称" Binding="{Binding ConAtt_Name,Mode=TwoWay}" />
                                            <sdk:DataGridTextColumn Header="附件资料" Binding="{Binding ConAtt_Name,Mode=TwoWay}">
                                            </sdk:DataGridTextColumn>
                                            <sdk:DataGridTextColumn Header="操作员编号" Binding="{Binding ConAtt_MakerId,Mode=TwoWay}" IsReadOnly="True" Visibility="Collapsed"></sdk:DataGridTextColumn>
                                            <sdk:DataGridTextColumn Header="操作员名称" Binding="{Binding ConAtt_MakerName,Mode=TwoWay}" IsReadOnly="True" />
                                            <sdk:DataGridTextColumn Header="备注" Binding="{Binding ConAtt_Remark,Mode=TwoWay}" />
                                            <sdk:DataGridTemplateColumn Header="预览" Width="90" >
                                                <sdk:DataGridTemplateColumn.CellTemplate>
                                                    <DataTemplate>
                                                        <HyperlinkButton Content="查看" Margin="5" Click="HyperlinkButton_Click"></HyperlinkButton>
                                                    </DataTemplate>
                                                </sdk:DataGridTemplateColumn.CellTemplate>
                                            </sdk:DataGridTemplateColumn>
                                        </sdk:DataGrid.Columns>
                                    </sdk:DataGrid>
                                    <Button Height="20" Width="80" Margin="5" Content="添加文件" Grid.Row="1" HorizontalAlignment="Left" Command="{Binding UploadCommd}">
                                    </Button>
                                </Grid>

private void HyperlinkButton_Click(object sender, RoutedEventArgs e)
        {
//获取当前选择行的实体对象
            var conAttachmentModel = gridConAttachmentModel.SelectedItem as ConAttachmentModel;
            if (conAttachmentModel != null)
            {
//如果不为空 把获取到的对象作为参数传入 web端 用来打开文件
                RequestService.Sent(ContractManageUriNames.OpenContractFiles, conAttachmentModel,
                                delegate(object sent, ResponseArgs args) {  });
            }
        }

//打开文件
 public void OpenContractFiles(ConAttachmentModel conAttachmentModel)
        {
            //获取文件类型
            // var filesType = conAttachmentModel.ConAtt_Name.Substring(conAttachmentModel.ConAtt_Name.LastIndexOf("."));
            //获取二进制流文件
            var filebyte = conAttachmentModel.ConAtt_Files;
            //创建的文件路径
            var path = @"C:\Documents and Settings\Administrator\Local Settings\Temporary Internet Files\\" + conAttachmentModel.ConAtt_Name;
            //按照路径实例化文件
            var file = new FileStream(path, FileMode.Create, FileAccess.Write);
            //实例化一个用于写的 BinaryWriter
            var bw = new BinaryWriter(file);
            //将传进来的二进制字符转换为8位无符号整数数组再写进去
            bw.Write(filebyte);
            bw.Close();   //关闭二进制流写入器
            file.Close();  //关闭文件流

            //创建Process命令
            var cmd = new Process();
            //创建要运行的文件或者程序
            var startfile = new ProcessStartInfo
                         {
                             FileName = file.Name,//文件完全路径
                             WindowStyle = ProcessWindowStyle.Normal,//Windows窗口样式
                             UseShellExecute = true//为true，则用默认的打开方式打开，如果是exe等，设置为false 
                         };
            cmd.StartInfo = startfile;
            cmd.Start(); //打开文件
        }