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使用1消费Web服务的优缺点是什么?事件/ 2。IAsyncResult?

iasyncresult events web-services c#

Edward Tanguay · 技术社区 · 15 年前

我做了一个wpf示例,它使用 Web服务 ( www.webservicex.com/globalweather.asmx )有两种不同的方式:

具有事件这样地:

public Window1()
{
    InitializeComponent();
    DataContext = this;

    Location = "loading...";
    Temperature = "loading...";
    RelativeHumidity = "loading...";

    client.GetWeatherCompleted += 
            new EventHandler<GetWeatherCompletedEventArgs>(client_GetWeatherCompleted);
    client.GetWeatherAsync("Berlin", "Germany");
}

void client_GetWeatherCompleted(object sender, GetWeatherCompletedEventArgs e)
{
    XDocument xdoc = XDocument.Parse(e.Result);

    Location = xdoc.Descendants("Location").Single().Value;
    Temperature = xdoc.Descendants("Temperature").Single().Value;
    RelativeHumidity = xdoc.Descendants("RelativeHumidity").Single().Value;
}

并与 开始/结束方法和IAsyncResult 这样地:

public Window1()
{
    InitializeComponent();
    DataContext = this;

    Location = "loading...";
    Temperature = "loading...";
    RelativeHumidity = "loading...";

    client.BeginGetWeather("Berlin", "Germany", new AsyncCallback(GotWeather), null);
}

void GotWeather(IAsyncResult result)
{
    string xml = client.EndGetWeather(result).ToString();
    XDocument xdoc = XDocument.Parse(xml);

    Location = xdoc.Descendants("Location").Single().Value;
    Temperature = xdoc.Descendants("Temperature").Single().Value;
    RelativeHumidity = xdoc.Descendants("RelativeHumidity").Single().Value;

}

这两种方法似乎执行着完全相同的任务。

它们的优点和缺点是什么?你什么时候用一个而不是另一个?