theia webide如何Theia的Workspace API来选择文件，给出代码示例

以下是使用 Theia 的 Workspace API 选择文件的代码示例：

import * as theia from '@theia/plugin';

async function main() {
  // Get the active workspace folder.
  const workspaceFolder = theia.workspace.workspaceFolders[0];

  // Show a quick pick menu to select a file.
  const fileUri = await theia.window.showQuickPick(
    theia.workspace.findFiles(
      {
        base: workspaceFolder.uri.toString(),
        // This pattern matches all files in the workspace folder.
        pattern: '**/*'
      },
      // Ignore folders, show only files in the quick pick menu.
      { relativeTo: workspaceFolder.uri }
    ),
    { canPickMany: false }
  );

  if (!fileUri) {
    return;
  }

  // Do something with the selected file.
  console.log(`Selected file: ${fileUri.toString()}`);
}

main();