请教WPF中下传文件或者打开文件如何实现，类似下传图片的那个选择图片的功能

 private void FindPic_Click(object sender, RoutedEventArgs e)        {            OpenFileDialog dialog = new OpenFileDialog();            dialog.Filter = "PNG File(*.png)|*.png"; ;            dialog.Multiselect = false;            if (dialog.ShowDialog() == true)            {                FileStream fs = new FileStream(dialog.FileName, FileMode.Open, FileAccess.Read);                BinaryReader br = new BinaryReader(fs);                this._imageBinary = br.ReadBytes((int)fs.Length);                this._imgLocalPath = dialog.FileName;                br.Close();                fs.Close();                this.IMG.Source = ByteArrayToBitmapImage(this._imageBinary);            }        }BitmapImage ByteArrayToBitmapImage(byte[] byteArray)        {            BitmapImage bmp = null;            try            {                bmp = new BitmapImage();                bmp.BeginInit();                bmp.StreamSource = new MemoryStream(byteArray);                bmp.EndInit();            }            catch            {                bmp = null;            }            return bmp;        }