基于HTML5 FileSystem API的使用介绍_html5教程技巧

window.requestFileSystem = window.requestFileSystem || window.webkitRequestFileSystem; //文件系统请求标识
window.resolveLocalFileSystemURL = window.resolveLocalFileSystemURL || window.webkitResolveLocalFileSystemURL; //根据URL取得文件的读取权限

window.requestFileSystem(window.PERSISTENT, //persistent(永久) or temporary(临时)
1024*1024, //1M
onInitFs, //成功后的回调函数
errorHandler); //错误后的回调函数

function onInitFs(fs){
fs.root.getDirectory('catwrite_documents', {create: true}, function(dirEntry) {
console.log('You have just created the ' + dirEntry.name + ' directory.');
}, errorHandler);
}
//错误回调
function errorHandler(err){
var msg = 'An error occured: ';
switch (err.code) {
case FileError.NOT_FOUND_ERR:
msg += 'File or directory not found';
break;
case FileError.NOT_READABLE_ERR:
msg += 'File or directory not readable';
break;
case FileError.PATH_EXISTS_ERR:
msg += 'File or directory already exists';
break;
case FileError.TYPE_MISMATCH_ERR:
msg += 'Invalid filetype';
break;
default:
msg += 'Unknown Error';
break;
};
console.log(msg + err);
}

void queryUsageAndQuota(
in DOMString url,
in EntryCallback successCallback,
in optional ErrorCallback errorCallback
);

window.webkitStorageInfo.queryUsageAndQuota(webkitStorageInfo.PERSISTENT,
function(used, remaining){
if(remaining == ""){
console.log("未申请空间。");
}else{
console.log("已使用空间"+used);
console.log("全部空间"+remaining);
}
},
errorHandler); </p><p>

void resolveLocalFileSystemURL(
in DOMString url,
in EntryCallback successCallback,
in optional ErrorCallback errorCallback
);

var url = "filesystem:http://" + window.location.host + "/persistent/catwrite_documents/";
window.resolveLocalFileSystemURL(url,function(fileEntry){
console.log(fileEntry);
var dirReader = fileEntry.createReader();
var readEntries = function(){
dirReader.readEntries(function(results){
if(!results.length){
create_file_title("默认文件", "");
console.log("没有文件！");
}else{
console.log("读取到" + results.length + "个文件");
for(var i = 0; i < results.length; i++){
console.log(results[i].name);
getFileContentByName(fileEntry, results[i].name);
}
}
},errorHandler);
};
readEntries();
},errorHandler);