wp7-页面值传递及小生命周期

xaml页跟xaml页之间的值传递：

向Page1页面中传递值：

 

1  NavigationService.Navigate(new Uri("/Page1.xaml?name=" + txtName.Text, UriKind.Relative));

 

 

 

在page1中接受传递过来的值

 

1 textBlock1.Text=  NavigationContext.QueryString["name"];

 

当我们传递比较复杂的值的时候 就不能像上面那样简单的传递，比如a=b&c=d，我们就要考虑用EscapeDataString来进行转义后在传递

1    NavigationService.Navigate(new Uri("/Page1.xaml?name="+Uri.EscapeDataString("a=b&c=d") , UriKind.Relative));

当我们需要传递一个比上面还要复杂的对象怎么办呢？比如我们需要传递的是一个Buttun按钮

 

 1  private void button1_Click(object sender, RoutedEventArgs e)

 2         {

 3             NavigationService.Navigate(new Uri("/Page1.xaml?name="+Uri.EscapeDataString("a=b&c=d") , UriKind.Relative));

 4             Page1.btn = button1;

 5         }

 6 

 7 

 8   public static Button btn;

 9         private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)

10         {

11             textBlock1.Text = (string)btn.Content;

12         }

 

 

 

这样就把前一个页面的Button按钮对象传递过来了 ！非常的灵活

 

 1 private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)

 2         {

 3             MessageBox.Show("PhoneApplicationPage_Loaded");

 4            

 5         }

 6         protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)

 7         {

 8                 base.OnNavigatedTo(e);

 9                 MessageBox.Show("OnNavigatedTo");

10         }

11         protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)

12         {

13                 base.OnNavigatedFrom(e);

14                 MessageBox.Show("OnNavigatedFrom");

15         }

16         protected override void OnNavigatingFrom(System.Windows.Navigation.NavigatingCancelEventArgs e)

17         {

18                 base.OnNavigatingFrom(e);

19                 MessageBox.Show("OnNavigatingFrom--Cancel");

20         }

21         protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)

22         {

23                 base.OnBackKeyPress(e);

24                 MessageBox.Show("OnBackKeyPress");
           }

 

 

 

执行的顺序是

加载时

OnNavigatedTo  页面变为活动页面时调用

PhoneApplicationPage_Loaded  

退出时：

OnBackKeyPress 设备硬件按下后退鍵是调用

OnNavigatingFrom--Cancel  刚好在页面不在是活动页面之前时调用

OnNavigatedFrom 在页面不在是活动页面时调用

 

OnBackKeyPress 的妙用：当我们在程序中弹出一个消息框时。如果直接在手机硬件上按后退鍵会直接退出程序，，这个时候我们就可以在OnBackKeyPress 这个方法中把后退的命令改成关闭消息框的命令！

 

服务端跟xaml页面的值传递

我们先简单的配置下服务端Handler.ashx：

 1 string action = context.Request["action"];

 2         if (action == "login")

 3         {

 4             string username = context.Request["username"];

 5             string password = context.Request["password"];

 6             if (username == "admin" && password == "123")

 7             {

 8                 context.Response.Write("ok");

 9             }

10             else

11             {

12                 context.Response.Write("error");

13             }

14         }

简单的设计一个登陆的界面；

给登录注册点击事件

 1  private void button1_Click(object sender, RoutedEventArgs e)

 2         {

 3             WebClient wc = new WebClient();

 4             wc.DownloadStringCompleted += new DownloadStringCompletedEventHandler(wc_DownloadStringCompleted);

 5             wc.DownloadStringAsync(new Uri("http://192.168.1.98:1174/WebSite14/Handler.ashx?action=login&username=" + Uri.EscapeDataString(textBox1.Text) + "&password=" + Uri.EscapeDataString(textBox2.Text)));

 6         }

 7 

 8         void wc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)

 9         {

10             if (e.Error != null)

11             {

12                 MessageBox.Show("错误");

13             }

14             else

15                 if (e.Result == "ok")

16                 {

17                     MessageBox.Show("登录成功");

18                 }

19                 else

20                     if (e.Result == "error")

21                     {

22                         MessageBox.Show("登录失败");

23                     }

24                     else

25                     {

26                         MessageBox.Show("未知错误");

27                     }

28         }

 这里要注意的是IP地址不能写127.0.0.1 或Localhost，因为手机跟电脑连接就自动构成一个局域网，并且手机自己本身就是个小电脑，Localhost就相当于访问手机自己

如果你是用手机跟电脑连接，或者模拟器跟电脑连接，则需要假设IIS，当然端口映射下也行，也可以设置下CassiniDev服务器，设置成any，允许外网访问。

 

假如我们要向手机客户端发送json数据呢。该怎么来接收并解析？

 

 1  string action = context.Request["action"];

 2        

 3         if (action=="test")

 4         {

 5             List<person> list = new List<person>();

 6             list.Add(new person { age=18,name="yzk" });

 7             list.Add(new person { name="zxh",age=17 });

 8             JavaScriptSerializer js=new JavaScriptSerializer();

 9          string json=   js.Serialize(list);

10             context.Response.Write(json);

11         }

12     }

13  

14     public bool IsReusable {

15         get {

16             return false;

17         }

18     }

19     public class person

20     {

21         public string name

22         {

23             get;

24             set;

25         }

26         public int age

27         {

28             get;

29             set;

30         }

31     }

 

 

 

然后我们在客户端接受json数据-在界面上托一个按钮并注册点击事件

 

 1 private void button2_Click(object sender, RoutedEventArgs e)

 2         {

 3             WebClient sc = new WebClient();

 4             sc.DownloadStringCompleted += new DownloadStringCompletedEventHandler(sc_DownloadStringCompleted);

 5             sc.DownloadStringAsync(new Uri("http://192.168.1.98:1174/WebSite14/Handler.ashx?action=test"));

 6         }

 7 

 8         void sc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)

 9         {

10             if (e.Error != null)

11             {

12                 MessageBox.Show("错误");

13             }

14             else

15             {

16                 string json = e.Result;

17                 List<person> list = new List<person>();

18                 JArray persons = (JArray)JsonConvert.DeserializeObject(json);

19               foreach (var item in persons)

20               {

21                   string name=item["name"].ToString();

22                   int age = int.Parse(item["age"].ToString());

23               }

24             }

25         }

26     }

27     public class person : DependencyObject

28     {

29 

30 

31         public int age

32         {

33             get { return (int)GetValue(ageProperty); }

34             set { SetValue(ageProperty, value); }

35         }

36 

37         // Using a DependencyProperty as the backing store for age.  This enables animation, styling, binding, etc...

38         public static readonly DependencyProperty ageProperty =

39             DependencyProperty.Register("age", typeof(int), typeof(person), null);

40 

41 

42         public string name

43         {

44             get { return (string)GetValue(nameProperty); }

45             set { SetValue(nameProperty, value); }

46         }

47 

48         // Using a DependencyProperty as the backing store for name.  This enables animation, styling, binding, etc...

49         public static readonly DependencyProperty nameProperty =

50             DependencyProperty.Register("name", typeof(string), typeof(person), null);

51 

52 

53 

54     }

 

 

 

这里解析服务端发送过来的数据，我们要引用Newtonsoft.Json.dll来帮我们解析