wp7-页面值传递及小生命周期(xaml页跟xaml页之间的值传递)

作者:袖梨 2022-06-26

xaml页跟xaml页之间的值传递:

向Page1页面中传递值:

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

  

在page1中接受传递过来的值

 代码如下 复制代码
 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

 代码如下 复制代码
   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

 代码如下 复制代码

 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

 代码如下 复制代码
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?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?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:

 代码如下 复制代码
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

 代码如下 复制代码
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?

 代码如下 复制代码
 string action = context.Request["action"];
       
         if (action=="test")
         {
             List list = new List();
             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

 代码如下 复制代码

 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 list = new List();
                 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

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