c# - 创建通用异步任务函数

Question

我创建了一个使用async/await 返回对象的函数。我想使该函数通用，以便它可以返回我传入的任何对象。代码是样板，除了要返回的对象。我希望能够调用 GetAsync 并让它返回正确的对象

public Patron getPatronById(string barcode)
{
    string uri = "patrons/find?barcode=" + barcode;
    Patron Patron =  GetAsync(uri).Result;
    return Patron;
}

private async Task<Patron> GetAsync(string uri)
{
    var client = GetHttpClient(uri);
    var content = await client.GetStringAsync(uri);
    JavaScriptSerializer ser = new JavaScriptSerializer();
    Patron Patron = ser.Deserialize<Patron>(content);
    return Patron;
}

Answer 1

泛型方法呢？

private async Task<T> GetAsync<T>(string uri)
{
    var client = GetHttpClient(uri);
    var content = await client.GetStringAsync(uri);
    var serializer = new JavaScriptSerializer();
    var t = serializer.Deserialize<T>(content);
    return t;
}

通常，您应该将此方法放在另一个类中并使其成为public，以便它可以被不同类中的方法使用。

关于调用此方法的方式，您可以尝试以下方式:

 // I capitalized the first letter of the method, 
 // since this is a very common convention in .NET
 public Patron GetPatronById(string barcode)
 {
     string uri = "patrons/find?barcode=" + barcode;
     var Patron =  GetAsync<Patron>(uri).Result;
     return Patron;
 }

注意:在上面的代码片段中，我假设您没有将 GetAsync 移动到另一个类中。如果你移动它，那么你必须做一个微小的改变。

更新

I'm not following what you mean by your note. Do I need to make GetPatronById a task function as well - like Yuval has done below?

我的意思是这样的:

// The name of the class may be not the most suitable in this case.
public class Repo
{
    public static async Task<T> GetAsync<T>(string uri)
    {
        var client = GetHttpClient(uri);
        var content = await client.GetStringAsync(uri);
        var serializer = new JavaScriptSerializer();
        var t = serializer.Deserialize<T>(content);
        return t;
    }
}

public Patron GetPatronById(string barcode)
{
     string uri = "patrons/find?barcode=" + barcode;
     var Patron =  Repo.GetAsync<Patron>(uri).Result;
     return Patron;
}