android - 使用 Cordova 下载文件

Question

尽管在文档或本论坛中找到了许多示例，但我找不到使用 Cordova 下载文件的方法...

首先，我得到 rootFS:

function gotFS(fileSystem) {
    console.log("got filesystem");
    // save the file system for later access
    console.log(fileSystem.root.fullPath);
        // displays "/" on desktop
        // displays "file:///mnt/sdcard" on android with SD Card
    window.rootFS = fileSystem.root;
}

document.addEventListener('deviceready', function() {                
    window.requestFileSystem  = window.requestFileSystem || window.webkitRequestFileSystem;
    window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, gotFS, function(){
        console.log("error getting LocalFileSystem");
    });
}, false);

上传脚本:

// Creating the image directory
imageDir = rootFS.getDirectory("imagesContent", {create: true},
    function(){
        // Success
    },
    function(error){
        console.log("ERROR getDirectory");
        console.log(error);
    }
);

// Creating and Downloading the image
    imgFile = imageDir.getFile(filename, {create: true, exclusive: true},
        function (){     
            var localPath = rootFS.fullPath+'/imagesContent/'+filename;
            fileTransfer = new FileTransfer();        
            fileTransfer.download('http://example.com/images/'+filename,
                localPath,
                function(entry) {
                    console.log("download complete: " + entry.fullPath);
                },
                function (error) {
                    console.log(error);
                    console.log('download error: ' + error.code);
                    console.log("download error source " + error.source);
                    console.log("download error target " + error.target);
                }
            );
        },
        function (error){
            console.log("ERROR getFile");
            console.log(error);
        }
    );

我在控制台中收到此错误:Uncaught TypeError:

Cannot call method 'getFile' of undefined

uri在config.xml中授权。

Answer 1

我认为问题出在这一行:imageDir = rootFS.getDirectory("imagesContent", {create: true},function(), function()) 我不认为调用 getDirectory 应该实际返回目录名称，就像您期望的那样，这就是为什么您的 imageDir 对象未定义的原因。

使用 FileTransfer.download() 方法从服务器下载内容可能更容易:http://docs.phonegap.com/en/edge/cordova_file_file.md.html#FileTransfer

var fileTransfer = new FileTransfer();
var uri = encodeURI("http://some.server.com/download.php");

fileTransfer.download(
    uri,
    filePath,
    function(entry) {
        console.log("download complete: " + entry.fullPath);
    },
    function(error) {
        console.log("download error source " + error.source);
        console.log("download error target " + error.target);
        console.log("upload error code" + error.code);
    },
    false,
    {
        headers: {
            "Authorization": "Basic dGVzdHVzZXJuYW1lOnRlc3RwYXNzd29yZA=="
        }
    }
);