uniapp本地文件读写操作
说明
主要是封装官方文档里面的
官方文档地址:https://www.html5plus.org/doc/zh_cn/io.html
最新整理
代码
/**
* 获取文件,文件不存在会自动创建()
* @param {Object} fileName 可以是文件名，也可以是/路径/文件名
* @param {Object} dirEntry 文件对象,可以为空
* @return 文件Entry
*/
export async function getFileEntryAsync(fileName,dirEntry){
// console.log("[getFileEntryAsync]开始执行")
return new Promise((resolve) => {
plus.io.requestFileSystem(
plus.io.PRIVATE_DOC,
function(fs) {
// console.log("[getFileEntryAsync]fileName is :" + fileName)
let entry = dirEntry || fs.root;
entry.getFile(
fileName, {create: true},
function(fileEntry) {
// console.log("[getFileEntryAsync] 执行完成")
resolve(fileEntry);
},function(ex){console.log(ex)}
);
}
);
})
}
/**
* 获取文件夹，不存在会自动创建
* @param {Object} dirName
*/
export async function getDirEntryAsync(dirName) {
return new Promise(async (resolve) => {
plus.io.requestFileSystem(plus.io.PRIVATE_DOC, function(fs) {
fs.root.getDirectory(dirName, {
create: true
}, function(dirEntry) {
resolve(dirEntry);
})
})
})
}
/**
* 获取通过fileEntry获取file，不存在会自动创建
* @param {Object} fileName
* @param {Object} dirEntry
*/
export async function getFileAsync(fileName, dirEntry) {
// console.log("[getFileAsync]")
return new Promise(async (resolve) => {
let fileEntry = await getFileEntryAsync(fileName, dirEntry);
fileEntry.file(function(file) {
resolve(file);
});
})
}
/**
* 读取文件中的内容
* @param {Object} path
* @param {Object} dirEntry
*/
export async function getFileContextAsync(path, dirEntry) {
let deffered;
let fileReader = new plus.io.FileReader();
fileReader.onloadend = function(evt) {
deffered(evt.target);
}
let file = await getFileAsync(path, dirEntry);
fileReader.readAsText(file, 'utf-8');
return new Promise((resolve) => {
deffered = resolve;
});
}
/**
* 向文件中写入数据
* @param {Object} path 要写入数据的文件的位置
* @param {Object} fileContext 要写入的内容
* @param {Object} dirEntry 文件夹，可不写使用默认
*/
export async function writeContextToFileAsync(path,fileContext, dirEntry) {
let fileEntry =await getFileEntryAsync(path);
let file =await getFileAsync(path);
return new Promise((resolve) => {
fileEntry.createWriter( async writer => {
// 写入文件成功完成的回调函数
writer.onwrite = e => {
console.log("写入数据成功");
resolve()
};
// 写入数据
writer.write(fileContext);
})
});
}
/**
* 追加写入数据
* @param {Object} path 要写入数据的文件的位置
* @param {Object} fileContext 要写入的内容
* @param {Object} dirEntry 文件夹，可不写使用默认
*/
export async function AddOnWrite(path,fileContext, dirEntry){
let data = await getFileContextAsync(path,dirEntry);
let fileEntry = await getFileEntryAsync(path);
let file = await getFileAsync(path);
return new Promise((resolve) => {
fileEntry.createWriter( async writer => {
// 写入文件成功完成的回调函数
writer.onwrite = e => {
console.log("写入数据成功");
resolve(true)
};
// 写入数据
writer.write(data.result+fileContext);
})
});
}
/**
* 判断文件是否存在
* @param {Object} fileName
* @param {Object} dirEntry
*/
export async function existFileAsync(fileName, dirEntry){
return new Promise((resolve)=>{
plus.io.requestFileSystem(plus.io.PRIVATE_DOC, function(fs) {
let entry = dirEntry || fs.root;
let directoryReader = entry.createReader();
directoryReader.readEntries(function(entries) {
let isExist = entries.some(entry => entry.name === fileName);
resolve(isExist);
});
});
})
}
/**
* 遍历dirEntry，只遍历当前目录,深层次的目录暂不考虑
* @param {Object} dirEntry 目录名,若是为空则为应用沙盒目录
*/
export async function iterateDirectory(dirEntry){
if(dirEntry){
var dir = await getDirEntryAsync(dirEntry);
}
return new Promise((resolve)=>{
plus.io.requestFileSystem(plus.io.PRIVATE_DOC, function(fs) {
let entry = dir || fs.root;
let directoryReader = entry.createReader();
directoryReader.readEntries(function(entries) {
// entries.forEach((item, idx, arr)=>{
// if(idx===0) console.log("---------------"+entry.name+"目录-----------------");
// console.log(idx+1, item.name);
// if(idx===arr.length-1) console.log("---------------end-----------------");
// })
resolve(entries)
}, function(e) {
console.log("Read entries failed: " + e.message);
});
});
})
}
调用
//删除方法
getDirEntryAsync('_doc/1').then((res)=>{
removeFile(res,'222.txt');
})
之前整理的
创建或打开文件
//fileName 目录路径 dirEntry之前打开过的目录(没有则不填写)
function getFileEntry(fileName, dirEntry) {
return new Promise((resolve,reject) => {
plus.io.requestFileSystem(plus.io.PRIVATE_DOC, function(fs) {
let entry = dirEntry || fs.root;
entry.getFile(fileName, {
create: true
}, function(fileEntry) {
resolve(fileEntry);
}, function(e) {
reject(e);
});
});
})
}
创建或打开目录
function getDirEntry(dirName) {
return new Promise(async (resolve) => {
plus.io.requestFileSystem(plus.io.PRIVATE_DOC, function(fs) {
fs.root.getDirectory(dirName, {
create: true
}, function(dirEntry) {
resolve(dirEntry);
})
})
})
}
获取文件数据对象 fileName文件名路径 dirEntry文件夹路径(可以不填)
function getFile(fileName, dirEntry) {
return new Promise((resolve,reject) => {
getFileEntry(fileName, dirEntry).then(fileEntry=>{
fileEntry.file(function(file) {
file.close();
resolve(file);
},function(e){
file.close();
reject('失败');
});
})
})
}
获取文件内容 path文件路径 文件夹路径(可为空)
async function getFileContext(path, dirEntry) {
let deffered;
let fileReader = new plus.io.FileReader();
fileReader.onloadend = function(evt) {
deffered(evt.target);
}
let file = await getFile(path, dirEntry);
fileReader.readAsText(file, 'utf-8');
return new Promise((resolve) => {
deffered = resolve;
});
}
读取目录下所有文件
function getDirList(fileNamePath) {
return new Promise((resolve, reject) => {
let arr = [];
plus.io.resolveLocalFileSystemURL(
fileNamePath,
function(entry) {
var directoryReader = entry.createReader();
directoryReader.readEntries(
function(entries) {
for (var i = 0; i < entries.length; i++) {
// console.log("文件信息",entries[i].name);
arr.push(entries[i].name);
}
// console.log(arr);
resolve(arr);
// console.log(JSON.person(entries))
},
function(e) {
console.log('访问目录失败');
reject(e)
});
},
function(e) {
console.log('访问指定目录失败');
reject(e)
});
})
}
删除文件
function removeFlie(fliePath) {
return new Promise((resolve, reject) => {
plus.io.resolveLocalFileSystemURL(fliePath, function(entry) {
entry.remove(function(entry) {
resolve(true);
}, function(e) {
console.log('删除失败',e);
reject(false)
});
}, function(e) {
console.log('访问路径失败')
reject(false)
})
})
}
浙公网安备 33010602011771号