WinJS加载本地json文件

问题描述：

我正在为此努力奋斗.

我找不到从WinJS应用程序中的子文件夹打开简单json文件的方法.

I cannot find a way to open a simple json file from a subfolder in my WinJS App.

我尝试了Ajax和WinJS.xhr，但都无济于事.

I have tried Ajax and WinJS.xhr, both to no avail.

我还考虑过使用.NET中的File.Open之类的文件以老式"方式打开文件，但是除了WinJS.Application.local.readText以外，我都找不到其他东西，我都尝试使用绝对和相对路径.

I have also looked into opening the file the "old fashioned" way with something like File.Open in .NET, but I couldn't find anything besides WinJS.Application.local.readText, which I tried with both an absolute and a relative path.

我在这里尽头了，有人可以共享一个有效的代码段吗?

I'm at the end of my rope here, does anyone have a working snippet that you can share?

答

您可以使用以下格式的URL来引用应用程序包中的文件:

You can refer to files in the app package using URLs in the form:

ms-appx:///data/data.json

(请注意，有三个/字符-如果您错过了第三个字符，则会遇到问题)

(Notice that there are three / characters - if you miss the third one out, you'll have problems)

要读取和解析包含JSON对象的文件，可以使用Windows.Storage名称空间中的对象.分三个步骤-获取指向文件的StorageFile对象，读取文件的内容，然后解析JSON数据.这是我用来执行此操作的代码:

To read and parse a file that contains a JSON object, you can use the objects in the Windows.Storage namespace. There are three steps - to get a StorageFile object that points to the file, read the contents of the file and then parse the JSON data. Here is the code that I used to do this:

var url = new Windows.Foundation.Uri("ms-appx:///data/data.json");
Windows.Storage.StorageFile.getFileFromApplicationUriAsync(url).then(function (file) {
    Windows.Storage.FileIO.readTextAsync(file).then(function (text) {
        var parsedObject = JSON.parse(text);
        // do something with object
    });
});

有很多方法可以从文件中读取数据，但是我发现FileIO对象是最方便的.上面的代码假定文件中存在一个JSON对象描述.如果您的文件每行包含一个对象，那么您将需要:

There are lots of ways of reading the data from the file, but I find the FileIO object the most convenient. The code above assumes there is one JSON object description in the file. If you have a file that contains one object per line, then you'll need this:

var url = new Windows.Foundation.Uri("ms-appx:///data/data.json");
Windows.Storage.StorageFile.getFileFromApplicationUriAsync(url).then(function (file) {
    Windows.Storage.FileIO.readLinesAsync(file).then(function (lines) {
        lines.forEach(function (line) {
            var parsedObject = JSON.parse(line);
            // do something with object
        });
    });
});

这是一个细微的变化，它使用FileIO.readLinesAsync方法创建字符串数组，每个字符串都被解析为JSON对象.

This is a slight variation that uses the FileIO.readLinesAsync method to create an array of strings, each of which is parsed as a JSON object.

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