client-app/uni_modules/lemon-filePicker/utssdk/app-ios/index.uts

// 引用 iOS 原生平台 api
import {  UIDocumentPickerViewController, UIDocumentPickerMode, UIDocumentPickerDelegate, UIViewController } from "UIKit";
import { DispatchQueue } from 'Dispatch';
import { UTSiOS } from "DCloudUTSFoundation"
import { URL ,FileManager } from 'Foundation'
/**
 * 定义 接口参数
 */
type InfoOptions = {
	success ?: (res : UTSJSONObject) => void;
	fail ?: (res : UTSJSONObject) => void;
	complete ?: (res : UTSJSONObject) => void;
};
class DocumentPicker extends UIViewController implements UIDocumentPickerDelegate {
	docPicker! : UIDocumentPickerViewController
	infoOptions ?: InfoOptions

	documentPicker(controller : UIDocumentPickerViewController, @argumentLabel("didPickDocumentsAt") urls : URL[]) {
		const fileName=urls[0].lastPathComponent
		try {
			const res = {
				code: "0",
				filePath:urls[0].absoluteString,
				fileName: fileName,
				errMsg: 'fileselect:ok',
				detail: "文件读取成功"
			}
			
			if (this.infoOptions != null) {
				this.infoOptions?.success?.(res)
				this.infoOptions?.complete?.(res)
			}
		}catch (e) {
			console.log(e.message)
			const res_fail = {
				code: "1002",
				errMsg: 'fileselect:fail',
				detail: "文件不存在"
			}
			this.infoOptions?.fail?.(res_fail)
			this.infoOptions?.complete?.(res_fail)
		}
	}
	documentPickerWasCancelled(controller : UIDocumentPickerViewController) {
		const res = {
			code: "1004",
			errMsg: 'fileselect:fail',
			detail: "用户取消了选择"
		}
		this.infoOptions?.fail?.(res)
		this.infoOptions?.complete?.(res)
	}
	fileSelect(options : InfoOptions) {

		this.infoOptions = options
		DispatchQueue.main.async(execute = () : void => {
			const types = ["public.data"]
			if (this.docPicker == null) {
				this.docPicker = new UIDocumentPickerViewController(documentTypes = types, in = UIDocumentPickerMode.import)
				this.docPicker.delegate = this
			}
			UTSiOS.getCurrentViewController().present(this.docPicker, animated = true)
		})
	}
}
const docPicker : DocumentPicker = new DocumentPicker();

export default function fileSelect(options : InfoOptions) {

	docPicker.fileSelect(options)
}