C#如何打开选择文件对话框和选择目录对话框

private void BrowseButton_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog dialog = new OpenFileDialog();
            if(dialog.ShowDialog(this)== true)
            {
                LocationBox.Text = dialog.FileName;
            }
        }

private void DisplayButton_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                FolderBrowserDialog dialog = new FolderBrowserDialog();
                dialog.Description = "请选择文件路径";
                DialogResult result = dialog.ShowDialog();
                if(result == System.Windows.Forms.DialogResult.Cancel)
                {
                    return;
                }
                string folderPath = dialog.SelectedPath.Trim();
                DirectoryInfo theFolder = new DirectoryInfo(folderPath);
                if (theFolder.Exists)
                {
                    //操作
                    return;
                }

        /// <summary>
        /// 文件选择通用对话框
        /// </summary>
        public class FilesSelectDialog
        {
            public OpenFileDialog fileDialog;
            //默认打开路径
            public string DirPath = "D:\\";
            public string FilePath;
            public string Title;
            public string Filter= "图片(*.jpg,*.jpge,*.bmp,*.png)|*.jpg;*.jpge;*.bmp;*.png| 所有文件(*.*) |*.*";
            public FilesSelectDialog(string title)
            {
                Title = title;
                fileDialog = new OpenFileDialog();//打开文件对话框 
            }
            public bool Show()
            {
                fileDialog.InitialDirectory = DirPath;//初始化路径
                fileDialog.Filter = Filter;//过滤选项设置，文本文件，所有文件。
                fileDialog.FilterIndex = 0;//当前使用第二个过滤字符串
                fileDialog.RestoreDirectory = true;//对话框关闭时恢复原目录
                fileDialog.Title = Title;
                if (fileDialog.ShowDialog() == DialogResult.OK)
                {
                    //for (int i = 1; i <= fileDialog.FileName.Length; i++)
                    //{
                    //    if (fileDialog.FileName.Substring(fileDialog.FileName.Length - i, 1).Equals(@"\"))
                    //    {
                    //        //更改默认路径为最近打开路径
                    //        Path = fileDialog.FileName.Substring(0, fileDialog.FileName.Length - i + 1);
                    //        return true;
                    //    }
                    //}
                    FilePath = fileDialog.FileName;
                    try
                    {
                        DirPath = System.IO.Path.GetDirectoryName(FilePath);//更改默认路径为最近打开路径
                    }
                    catch (Exception)
                    {
                        return false;
                    }
                    return true;
                }
                else
                {
                    return false;
                }
            }
        }
FilesSelectDialog selectDialog = new FilesSelectDialog("请选择要转换的图片");
        private void Btn_OpenImsge_Click(object sender, EventArgs e)
        {
            //FilesSelectDialog selectDialog = new FilesSelectDialog("请选择要转换的图片");
            selectDialog.Filter = "图片(*.jpg,*.jpge,*.bmp,*.png)|*.jpg;*.jpge;*.bmp;*.png| 所有文件(*.*) |*.*";
            if (selectDialog.Show()==true)
            {
                SourceSrcBox.Text = selectDialog.FilePath;
                //MessageBox.Show(selectDialog.FilePath);
                DisplayImage(SourceSrcBox.Text);
            }
        }