在过去的 6 个小时里,我一直在尝试使用 phonegap 持久化数据,我的第一种方法是使用 localStorate API,但每次应用程序重新启动时都会被杀死,所以它没用。现在我通过将文件写入文件系统来实现它,但存在以下问题:
- 文件创建好了
- 该文件具有正确的内容
adb pull /data/data/[包名]/friends.txt)
我可以看到文件的内容 - 但是试图从中读取我总是得到NULL。
如果有人可以帮助我,这是我的代码......我现在没有想法:(
var friends = [];
// Initialize the Facebook SDK
document.addEventListener('deviceready', function() {
FB.init({
appId: '[myAppID]',
nativeInterface: CDV.FB,
useCachedDialogs: false
});
// Check if we already fetched our friends
readSavedContent();
});
function readSavedContent() {
window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, gotFileSystemForRead, fail);
}
function gotFileSystemForRead(fileSystem) {
fileSystem.root.getFile("friends.txt", {create: true, exclusive: false}, gotFileEntryForRead, fail);
}
function gotFileSystemForWrite(fileSystem) {
fileSystem.root.getFile("friends.txt", {create: true, exclusive: false}, gotFileEntryForWrite, fail);
}
function gotFileEntryForRead(fileEntry) {
var reader = new FileReader();
reader.onloadend = function(evt) {
alert("Data stored is " + evt.target.result);
};
reader.readAsText(fileEntry);
}
function gotFileEntryForWrite(fileEntry) {
fileEntry.createWriter(gotFileWriter, fail);
}
function gotFileWriter(writer) {
writer.onwriteend = function(evt) {
// show a message
alert(friends.length + " friends fetched, you should be able to see them if you restart the app");
};
writer.write(JSON.stringify(friends));
}
function fail(error) {
console.log(error.code);
alert(error);
}
function login() {
FB.login(function (response) {
console.log(JSON.stringify(response));
if (response.status === "connected") {
alert("logged in: fetching friends now");
// Fetch my friends
FB.api("/fql?q=" + encodeURIComponent('SELECT uid, first_name, last_name, email, pic, pic_big, is_app_user, devices FROM user WHERE uid IN (SELECT uid2 FROM friend WHERE uid1= me()) ORDER BY first_name LIMIT 2000'),
function(response) {
friends = response.data;
// Store the data to the disk
window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, gotFileSystemForWrite, fail);
}
);
} else {
alert('not logged in');
}
}, {
scope: "email"
});
}