文件分类
按所有者：
-
应用文件：所有者为应用，包括应用安装文件、应用资源文件、应用缓存文件等。
-
用户文件：所有者是登录到该终端设备的用户，包括用户私有的图片、视频、音频、文档等。
-
系统文件：与应用和用户无关的其他文件，包括公共库、设备文件、系统资源文件等。
应用沙箱（虚拟目录，仅应用自己可见）
应用文件路径详细
写文件
//WriteFile.ets
import { fileIo } from '@kit.CoreFileKit';
import { common } from '@kit.AbilityKit';
let context = getContext(this) as common.UIAbilityContext
let filesDir = context.filesDir;
/**
* 写文件
* 把内容写入一个文件
* @param content 内容字符串
*/
export function writeFile(content: string): void {
let filePath = filesDir + '/test.txt' //文件路径
// 用文件路径，创建一个文件流。w+: 覆盖式读写，无论该文件存在与否
let fileStream = fileIo.createStreamSync(filePath, "w+");
fileStream.writeSync(content);
fileStream.close();
}
读文件
//ReadFile.ets
import { fileIo } from '@kit.CoreFileKit';
import { common } from '@kit.AbilityKit';
import { buffer } from '@kit.ArkTS';
// 获取应用文件路径
let context = getContext(this) as common.UIAbilityContext;
let filesDir = context.filesDir;
let res: string = '';
export function readFile(): string {
//文件路径
let filePath = filesDir + '/test.txt'
//获取文件状态
let stat = fileIo.statSync(filePath)
let size = stat.size //文件大小
//设置一个读取缓冲区，大小与文件大小一致
let buf = new ArrayBuffer(size)
// 根据文件路径打开文件流
let fileStream = fileIo.createStreamSync(filePath, "r+")
// 读取信息到缓冲区，同步方法（sync）
fileStream.readSync(buf)
// 文件读取到缓冲区后，再转换为通用buffer类型（二进制）
let con = buffer.from(buf, 0)
//buffer二进制数据，转换为字符串类型
res = con.toString()
//关闭文件流
fileStream.close()
return res;
}
文件分享
应用场景：应用A主动分享文件给应用B，应用B完成文件接收。
- URI分享: 把文件在沙箱中的路径，转换成实际的物理路径（URI），即可分享。
文件分享: systemShare
//ShareFile.ets
import { Want, wantConstant } from '@kit.AbilityKit';
import { common } from '@kit.AbilityKit';
import { fileUri } from '@kit.CoreFileKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { promptAction } from '@kit.ArkUI';
import { uniformTypeDescriptor } from '@kit.ArkData';
import { systemShare } from '@kit.ShareKit';
let context = getContext(this) as common.UIAbilityContext;
let filesDir = context.filesDir;
export
function shareFile2(){
// 获取文件的沙箱路径
let filePath = filesDir + '/test.txt'
// 将沙箱路径转换为uri
let uri1 = fileUri.getUriFromPath(filePath)
let utd1 = ''
if (canIUse('SystemCapability.DistributedDataManager.UDMF.Core')) {
utd1 = uniformTypeDescriptor.UniformDataType.PLAIN_TEXT
}
let data = new systemShare.SharedData({
utd: utd1,
uri: uri1
})
let ctrl = new systemShare.ShareController(data)
ctrl.show(context,{
// 选用一种预览
previewMode: systemShare.SharePreviewMode.DETAIL,
// 选用一种选择模式, 例如单选
selectionMode: systemShare.SelectionMode.SINGLE
})
}
export default
function shareFile(){
// 获取文件的沙箱路径
let filePath = filesDir + '/test.txt'
// 将沙箱路径转换为uri
let uri = fileUri.getUriFromPath(filePath)
let want: Want = {
// 配置被分享文件的读写权限，例如对被分享应用进行读写授权
flags: wantConstant.Flags.FLAG_AUTH_READ_URI_PERMISSION |
wantConstant.Flags.FLAG_AUTH_WRITE_URI_PERMISSION,
// 配置分享应用的隐式拉起规则
action: 'ohos.want.action.sendData',
uri: uri,
type: 'text/plain'
}
context.startAbility(want)
.then(() => {
promptAction.showToast({
message: '分享成功'
})
})
.catch((err: BusinessError) => {
promptAction.showToast({
message: `分享失败：${err.code}, 原因：${err.message}`,
duration: 5000
})
});
}
文件选择器 - Picker
- PhotoViewPicker：图片/视频
- DocumentViewPicker：各式文件
- AudioViewPicker：音频
import { picker } from '@kit.CoreFileKit';
let photoPicker = new picker.PhotoViewPicker()
let docPicker = new picker.DocumentViewPicker()
let audioPicker = new picker.AudioViewPicker()
import fileIo from "@ohos:file.fs";
import picker from "@ohos:file.picker";
import type common from "@ohos:app.ability.common";
let context = getContext(this) as common.UIAbilityContext;
export async function photoPickerGetUri(): Promise<string> {
//picker的选项配置
let PhotoSelectOptions = new picker.PhotoSelectOptions();
PhotoSelectOptions.maxSelectNumber = 1; //最大可选数
let photoPicker = new picker.PhotoViewPicker();
try {
let result = await photoPicker.select(PhotoSelectOptions);
console.info('选择结果 uri: ' + JSON.stringify(result));
let photosUris = result.photoUris;
return Promise.resolve(photosUris[0].toString());
}
catch (e) {
console.error('出错: ' + JSON.stringify(e));
}
return Promise.reject();
}
export async function photoSave() {
let options = new picker.PhotoSaveOptions;
options.newFileNames = ['1.jpg']; //保存文件名
let picker1 = new picker.PhotoViewPicker();
try {
let result = await picker1.save(options);
let file = await fileIo.open(result[0], fileIo.OpenMode.READ_WRITE);
let buffer = context.resourceManager.getMediaContentSync({ "id": 16777238, "type": 20000, params: [], "bundleName": "com.example.filesmanger", "moduleName": "entry" }.id);
await fileIo.write(file.fd, buffer.buffer);
}
catch (e) {
console.error('保存失败：' + JSON.stringify(e));
}
}
Picker保存文件
import { picker, fileIo } from '@kit.CoreFileKit';
import { buffer } from '@kit.ArkTS';
export async function saveToUser(content: string) {
try {
let options = new picker.DocumentSaveOptions()
options.newFileNames = ['test123.txt']
let picker1 = new picker.DocumentViewPicker()
let result = await picker1.save(options)
//打开文件，读写模式
let file = fileIo.openSync(result[0], fileIo.OpenMode.READ_WRITE)
fileIo.writeSync(file.fd, content) //写入内容
console.info('保存成功， uri: ' + JSON.stringify(result))
} catch (error) {
console.error('保存错误：' + JSON.stringify(error));
}
}
export async function readUserFile(): Promise<string> {
try {
let options = new picker.DocumentSelectOptions()
let documentPicker = new picker.DocumentViewPicker()
let result = await documentPicker.select(options)
let file = fileIo.openSync(result[0], fileIo.OpenMode.READ_WRITE)
let buf = new ArrayBuffer(fileIo.statSync(file.fd).size)
fileIo.readSync(file.fd, buf)
let con = buffer.from(buf, 0)
return Promise.resolve(con.toString())
} catch (err) {
console.error('读取失败： ' + JSON.stringify(err));
}
return Promise.reject()
}
