[Windows8开发] 几个小知识点

判断网络连接：

ConnectionProfile profile = NetworkInformation.GetInternetConnectionProfile();
if (profile != null)
{
// 执行网络请求Code
}
else
{
//执行断网时的Code
}

Json反序列化

HttpClient hc = new HttpClient();
var save = await hc.GetAsync(new Uri("http://...+ Num));
string st = await save.Content.ReadAsStringAsync();
DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(num));
using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(st))) 
//字符类型可能不同 
{
num numresult = (num)json.ReadObject(ms);
//执行解析后的Code
}

实现页面间导航、跳转

private void About(object sender, RoutedEventArgs e)
{
    this.Frame.Navigate(typeof(About)); 
    //About是想要跳转的页面，About.xaml可以显示为typeof的类
}

 实现Snapped页面模式（禁止访问，类似于商店那样）

首先在XAML的<Page>下添加如下代码：

SizeChanged="Page_SizeChanged_1"

然后单击事件，转换到C#中，添加如下代码：

private void Page_SizeChanged_1(object sender, SizeChangedEventArgs e)
        {
            Window.Current.SizeChanged += (s1, s2) =>
            {
                ApplicationViewState myViewState = ApplicationView.Value;

                if (myViewState == ApplicationViewState.Snapped)
                {
                    this.Frame.Navigate(typeof(Snap)); //Snap 是跳转的页面名称(Snap.xaml)
                }
                else if (myViewState != ApplicationViewState.Snapped)
                {
                    this.Frame.Navigate(typeof(MainPage));
                }
            };
        }