cordova实现文件系统的读写

1.获取Document目录

getLocalDocumentEntry () {
        let persistent = null;
        if (cordova.platformId === 'android') {
            persistent = `${cordova.file.dataDirectory}files/`;
        } else {
            persistent = cordova.file.documentsDirectory;

        }
        return new Promise((resolve, reject) => {
            window.resolveLocalFileSystemURL(persistent,
                dirEntry => {
                    resolve(dirEntry);
                }, error => {
                    reject(error);
                });
        });
    }

2.创建目录

createDirectory (dirEntry, name, isCreate){
        return new Promise((resolve, reject) => {
            dirEntry.getDirectory(name, {create: isCreate}, subDirEntry => {
                resolve(subDirEntry);
            }, error => {
                reject(error);
            });
        });
    }

3.获取文件

getPrjectFile (filename, workEntry){
       return new Promise((resolve, reject) => {
           workEntry.getFile(filename, {create: true, exclusive: false}, fileEntry => {
               resolve(fileEntry);
           }, onErrorCreateFile => {
               reject(onErrorCreateFile);
           });
       });
   }

4.获取文件夹内所有文件

getProjectEntries (entry){
        return new Promise((resolve, reject) => {
            const reader = entry.createReader();
            reader.readEntries(entries => {
                console.log('entries', entries);
                resolve(entries);
            }, error => {
                console.log('error', error);
                reject(error);

            });
        });
    }

5.写入文件

writeFile (fileEntry, dataObj) {
        return new Promise((resolve, reject) => {
            fileEntry.createWriter(fileWriter => {

                fileWriter.onwriteend = () => {
                    console.log('Successful file write...');
                    resolve('success');
                };
                fileWriter.onerror = e => {
                    console.log(`Failed file write: ${e.toString()}`);
                    reject(e);
                };
                if (!dataObj) {
                    dataObj = new Blob(['some file data'], {type: 'text/plain'});
                }

                fileWriter.write(dataObj);
            });
        });

    }

6.读取文件内容

readFile (fileEntry) {
 return new Promise((resolve, reject) => {
            fileEntry.file(file => {
                const reader = new FileReader();
                reader.onloadend = function () {
                    resolve(this.result);
                };
                reader.readAsText(file);

            }, onErrorReadFile => {
                reject(onErrorReadFile);
            });
        });
    }

7.获取app目录

getAppEntry: function () {
        return new Promise((resolve, reject) => {
            const fileURL = `${cordova.file.applicationDirectory}www`;
            window.resolveLocalFileSystemURL(fileURL,
                appEntry => {
                    resolve(appEntry);
                }, error => {
                    reject(error);
                });
        });
    }