Question

我正在使用Javascript创建一个UWP应用。我需要将一些代码从C#转换为javascript 我正在关注如何添加应用内购买Documentation。

C#中的需求代码如下所示：

async void BuyFeature()
{
    if (!licenseInformation.ProductLicenses["featureName"].IsActive)
    {
        try
        {
            // The customer doesn't own this feature, so
            // show the purchase dialog.
            await CurrentAppSimulator.RequestProductPurchaseAsync("featureName", false);

            //Check the license state to determine if the in-app purchase was successful.
        }
        catch (Exception)
        {
            // The in-app purchase was not completed because
            // an error occurred.
        }
    }
    else
    {
        // The customer already owns this feature.
    }
}

正如您在第9行中看到的那样，有一个等待功能。我如何将其翻译成javascript？

所以在调用javascript后......

function abc() {
    Windows.ApplicationModel.Store.CurrentAppSimulator.requestProductPurchaseAsync("1", false);
    // something fancy here ... but that needs to wait
};

......我需要等到它返回一些内容然后继续执行该功能。

Answer 1

根据你的描述。我想你的问题是如何在UWP中使用JavaScript的异步函数。

在许多情况下，调用异步函数几乎与调用常规函数一样简单。不同之处在于您使用then或done方法为结果或错误分配处理程序并开始操作。

因此，您可以在JavaScript中使用RequestProductPurchaseAsync，如下所示。请注意，在Windows 8.1之后，RequestProductPurchaseAsync(System.String,System.Boolean)可能会被更改或不可用于发布。相反，请使用RequestProductPurchaseAsync(System.String)。

function abc() {
    Windows.ApplicationModel.Store.CurrentAppSimulator.requestProductPurchaseAsync("1").done(
        function (purchaseResults) {
            //TODO - purchaseResults is the return of requestProductPurchaseAsync method
        },
        function () {
            console.log("error: Unable to buy 1.");
        });
}

有关详细信息，请参阅Asynchronous patterns in UWP using JavaScript以及如何使用CurrentAppSimulator，您可以参考Trial app and in-app purchase sample。

Answer 2

我认为你正在寻找的是使用承诺，或许这样的事情：

function productPurchaseAsyncCallExample(){
    return {response:'test response',errorCode:'ok/fail etc..'};
    // or whatever the response is...
}

var requestProductPurchaseAsync = new Promise(function(resolve, reject){
    //We call resolve(...) when what we were doing async succeeded, and reject(...) when it failed.
    //In this example, we use setTimeout(...) to simulate async code. 
    //In reality, you will probabally using something like XHR or an HTML5 API.
    //setTimeout(function(){
    //    resolve({success:'yes', bool:true}); //Yay! Everything went well!
    //}, 2250);
    resolve(productPurchaseAsyncCallExample());
});

function BuyFeature() {
    if (true){ // your if statement check
        requestProductPurchaseAsync.then(function(data){
            console.log(data);
            // do the rest
        });
    }
};


BuyFeature();

Answer 3

function abc() {
    var ans=testFn('a','b'); // let testFn is your function and assume it returns 'txt'
    while(ans!="txt"){}
    //do rest of code
    
}

Javascript：听一个回调回调

3 个答案: