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：

 

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

 

 

 

在page1中接受传递过来的值

 

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

   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

 

 private void button1_Click(object sender, RoutedEventArgs e)
        {
            NavigationService.Navigate(new Uri("/Page1.xaml?name="+Uri.EscapeDataString("a=b&c=d") , UriKind.Relative));
            Page1.btn = button1;
        }


  public static Button btn;
        private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
        {
            textBlock1.Text = (string)btn.Content;
        }

 

 

 

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

 

private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
        {
            MessageBox.Show("PhoneApplicationPage_Loaded");
           
        }
        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
        {
                base.OnNavigatedTo(e);
                MessageBox.Show("OnNavigatedTo");
        }
        protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
        {
                base.OnNavigatedFrom(e);
                MessageBox.Show("OnNavigatedFrom");
        }
        protected override void OnNavigatingFrom(System.Windows.Navigation.NavigatingCancelEventArgs e)
        {
                base.OnNavigatingFrom(e);
                MessageBox.Show("OnNavigatingFrom--Cancel");
        }
        protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
        {
                base.OnBackKeyPress(e);
                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：

string action = context.Request["action"];
        if (action == "login")
        {
            string username = context.Request["username"];
            string password = context.Request["password"];
            if (username == "admin" && password == "123")
            {
                context.Response.Write("ok");
            }
            else
            {
                context.Response.Write("error");
            }
        }

简单的设计一个登陆的界面；

给登录注册点击事件

 private void button1_Click(object sender, RoutedEventArgs e)
        {
            WebClient wc = new WebClient();
            wc.DownloadStringCompleted += new DownloadStringCompletedEventHandler(wc_DownloadStringCompleted);
            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)));
        }

        void wc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
        {
            if (e.Error != null)
            {
                MessageBox.Show("错误");
            }
            else
                if (e.Result == "ok")
                {
                    MessageBox.Show("登录成功");
                }
                else
                    if (e.Result == "error")
                    {
                        MessageBox.Show("登录失败");
                    }
                    else
                    {
                        MessageBox.Show("未知错误");
                    }
        }

 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？

 

 string action = context.Request["action"];
       
        if (action=="test")
        {
            List<person> list = new List<person>();
            list.Add(new person { age=18,name="yzk" });
            list.Add(new person { name="zxh",age=17 });
            JavaScriptSerializer js=new JavaScriptSerializer();
         string json=   js.Serialize(list);
            context.Response.Write(json);
        }
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }
    public class person
    {
        public string name
        {
            get;
            set;
        }
        public int age
        {
            get;
            set;
        }
    }

 

 

 

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

 

private void button2_Click(object sender, RoutedEventArgs e)
        {
            WebClient sc = new WebClient();
            sc.DownloadStringCompleted += new DownloadStringCompletedEventHandler(sc_DownloadStringCompleted);
            sc.DownloadStringAsync(new Uri("http://192.168.1.98:1174/WebSite14/Handler.ashx?action=test"));
        }

        void sc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
        {
            if (e.Error != null)
            {
                MessageBox.Show("错误");
            }
            else
            {
                string json = e.Result;
                List<person> list = new List<person>();
                JArray persons = (JArray)JsonConvert.DeserializeObject(json);
              foreach (var item in persons)
              {
                  string name=item["name"].ToString();
                  int age = int.Parse(item["age"].ToString());
              }
            }
        }
    }
    public class person : DependencyObject
    {


        public int age
        {
            get { return (int)GetValue(ageProperty); }
            set { SetValue(ageProperty, value); }
        }

        // Using a DependencyProperty as the backing store for age.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty ageProperty =
            DependencyProperty.Register("age", typeof(int), typeof(person), null);


        public string name
        {
            get { return (string)GetValue(nameProperty); }
            set { SetValue(nameProperty, value); }
        }

        // Using a DependencyProperty as the backing store for name.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty nameProperty =
            DependencyProperty.Register("name", typeof(string), typeof(person), null);



    }

 

 

 

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