corodva操作文件类 目录浏览

#cordova-plugin-media 录音并打包上传

https://www.jianshu.com/p/e07f38434ffd

三、目录结构简单整理

Android File System Layout

Device Path	cordova.file.*	AndroidExtraFileSystems	r/w?	persistent?	OS clears	private
file:///android_asset/	applicationDirectory	assets	r	N/A	N/A	Yes
/data/data/<app-id>/	applicationStorageDirectory	-	r/w	N/A	N/A	Yes
cache	cacheDirectory	cache	r/w	Yes	Yes*	Yes
files	dataDirectory	files	r/w	Yes	No	Yes
Documents		documents	r/w	Yes	No	Yes
<sdcard>/	externalRootDirectory	sdcard	r/w	Yes	No	No
Android/data/<app-id>/	externalApplicationStorageDirectory	-	r/w	Yes	No	No
cache	externalCacheDirectry	cache-external	r/w	Yes	No**	No
files	externalDataDirectory	files-external	r/w	Yes	No	No

创建目录

var directoryEntry = fileSystem.root;
           //创建目录
 directoryEntry.getDirectory("MyDirectory", {create: true, exclusive: false}, onDirectorySuccess, onDirectoryFail);

创建文件

   //创建文件
    createFile :function() {
        //获取系统类型
        var type = window.TEMPORARY;
        var size = 5*1024*1024;
        //成功时获取的回调涵数
        window.requestFileSystem(type, size, successCallback, errorCallback)
        
        function successCallback(fs) {
           //开始读取文件 
           fs.root.getFile('log.txt', {create: true, exclusive: true}, function(fileEntry) {
              alert('File creation successfull!')
           }, errorCallback);
        }
     
        function errorCallback(error) {
           alert("ERROR: " + error.code)
        }
         
     },

路径操作：（获取Entry/转换路径）

1、requestFileSystem：仅两个目录 PERSISTENT / TEMPORARY

window.requestFileSystem(存储类型，期望存储空间大小(b字节)，成功回调，失败回调)
存储类型：LocalFileSystem.PERSISTENT / LocalFileSystem.TEMPORARY
返回 FileSystem {name: string, root: DirectoryEntry}

window.requestFileSystem(
    LocalFileSystem.PERSISTENT,  //永久目录
    //LocalFileSystem.TEMPORARY,  //临时目录
    0,  //如果是需要创建 PERSISTENT 永久文件 需要为0
    function (fs) {  //fs FileSystem  {name: string, root: DirectoryEntry}
        alert("fs名字：" + fs.name);  //persistent
        alert("DirectoryEntry："+fs.root);  // DirectoryEntry 对象
        alert("DirectoryEntry isFile："+fs.root.isFile);  //false
        alert("DirectoryEntry isDirectory："+fs.root.isDirectory);  //true
        alert("DirectoryEntry name："+fs.root.name);  //""
        alert("DirectoryEntry fullPath："+fs.root.fullPath);  // /
        alert("DirectoryEntry fileSystem："+fs.root.fileSystem);  // undefined
        alert("DirectoryEntry nativeURL："+fs.root.nativeURL);  // file:///data/data/com.example.hello/files/files/
    },
    function (file_error) {
        alert("错误：" + file_error);
    }
);

2、window.resolveLocalFileSystemURL：可以转换路径（native file <-> cdvfile）

window.resolveLocalFileSystemURL("url", 成功回调， 错误回调);

var native_path = "file:///";
// var cdvfile_path = "cdvfile://localhost/persistent/";
window.resolveLocalFileSystemURL(
    native_path,
    //cdvfile_path,
    function (entry) {
        alert("entry isFile："+entry.isFile);  //false
        alert("entry isDirectory："+entry.isDirectory);  //true
        alert("entry name："+entry.name);  //""
        alert("entry fullPath："+entry.fullPath);  // /
        alert("entry fileSystem："+entry.fileSystem);  // undefined
        alert("entry nativeURL："+entry.nativeURL);  // file:///data/data/com.example.hello/files/files/
        alert('entry toURL: ' + entry.toURL());  // file:///data/data/com.example.hello/files/files/
        alert('entry toInternalURL: ' + entry.toInternalURL());  // cdvfile://localhost/persistent/
    },
    function(file_error){
        alert("错误：" + file_error);
    }
);

开始遍历目录

    readUrl:function(){
        var native_path = cordova.file.externalRootDirectory;
        //cordova.file.dataDirectory
        window.resolveLocalFileSystemURL(native_path, function (entry) {
            var entry = entry;  //通过 requestFileSystem / resolveLocalFileSystemURL 获得
            entry.getDirectory(
                "",
                {create: false},
                function (directory_entry) {
                    directory_entry.createReader().readEntries(  //如果 entry 已经是 DirectoryEntry 可以直接从这步开始
                        function(entry_array){
                            console.log("遍历目录：");
                            for(var index in entry_array){
                                console.log(entry_array[index].toURL());  //native file
                                console.log(entry_array[index].toInternalURL());  //cdvfile
                            }
                        },
                        file_error2
                    );
                },
                file_error
            );

        }, onErrorLoadFs);
        function file_error2 (file_error2) {console.log("遍历错误：" + file_error);}

        function file_error(file_error){}

        function onErrorLoadFs(error){

        }
    },