页面转换问题

Question

    private void Videobutton2_Click(object sender, RoutedEventArgs e)
    {
      NavigationService.Navigate(new Uri("/Views/Video.xaml", UriKind.Relative));
    }

求助：

假设我的程序里没有上述的Video.xaml这个Page，当我点击按钮运行上段代码时，为什么程序没有报错，而是直接退出程序了？

Answer 1

判断Navigate方法的返回值

NavigationService.Navigate Method

Windows Phone

 

1/28/2011

Navigates to the content specified by the uniform resource identifier (URI).

 

Namespace: System.Windows.Navigation
Assembly: Microsoft.Phone (in Microsoft.Phone.dll)

Syntax

---

public bool Navigate(
	Uri source
)

Parameters

source

Type: System.Uri
The URI of the content to navigate to.

Return Value

Type: System.Boolean
Returns Boolean. True if the navigation started successfully; otherwise, false.

Platforms

---

Windows Phone OS 7.0 and later

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Cedar

Answer 2

或者捕获NavigationService.NavigationFailed Event

http://msdn.microsoft.com/en-us/library/system.windows.navigation.navigationfailedeventargs(v=VS.92).aspx

NavigationFailedEventArgs Class

Windows Phone

1/28/2011

Provides data for the NavigationFailed event of the NavigationService class and the NavigationFailed event of the Frame class.

 

Namespace: System.Windows.Navigation
Assembly: Microsoft.Phone (in Microsoft.Phone.dll)

Syntax

---

public sealed class NavigationFailedEventArgs : EventArgs

Inheritance Hierarchy

---

System.Object
System.EventArgs
System.Windows.Navigation.NavigationFailedEventArgs

Thread Safety

---

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

---

Windows Phone OS 7.0 and later

 

See Also

---

Reference

NavigationFailedEventArgs Members

System.Windows.Navigation Namespace

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Cedar

Answer 3

额，没有看懂……

能写下例子吗？

Answer 4

在App.xaml.cs中找到RootFrame_NavigationFailed方法，这个方法是捕获NavigationService.NavigationFailed Event处理页面跳转错误的。

在此方法中添加如下代码，设置跳转错误时转向默认页MainPage.xaml

RootFrame.Navigate(new Uri("/MainPage.xaml", UriKind.Relative));

修改后的代码如下：

// Code to execute if a navigation fails
        private void RootFrame_NavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // A navigation has failed; break into the debugger
                System.Diagnostics.Debugger.Break();
            }
            RootFrame.Navigate(new Uri("/MainPage.xaml", UriKind.Relative));
        }

---

Cedar

Answer 5

多谢版主，你那个我试了，是没问题的……

但我想退回上一界面，而不是只要一打开错误，就退回到主页面……

Answer 6

我晕，又仔细试了下，不行了

        private void RootFrame_NavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // A navigation has failed; break into the debugger
                System.Diagnostics.Debugger.Break();
            }
            RootFrame.Navigate(new Uri("/MainPage.xaml", UriKind.Relative));
        }

如果是按着F10，一句一句的走完，页面会卡掉

如果是按F5跳过的话，会一直重复着自动就在     System.Diagnostics.Debugger.Break();中断

Answer 7

建议楼主在编写代码时就要尽量避免导航到不存在的页面，如果在调试过程中发现了，就需要及时更正。

我觉得在正式发布版本的程序中不应该存在这种导航到的页面不存在的情况。

在Release版本下，应该就不会执行 System.Diagnostics.Debugger.Break();这行语句了。

应用程序可能会直接退出。

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专注于Windows Phone

Answer 8

请尝试升级开发工具集。

2011-2，微软发布SDK的更新包,包含了：模拟器的更新、开发资源的更新、增加了 Capability Detection Tool 、Connect Tool ，以及bingmap control的更新、增加复制粘贴功能等。
下载地址：http://www.microsoft.com/downloads/en/details.aspx?FamilyID=49B9D0C5-6597-4313-912A-F0CCA9C7D277

Windows Phone Developer Tools January 2011 Update

Overview

--------------------------------------------------------------------------------

Important Installation Instructions
There are TWO separate installations for the Windows Phone Developer Tools January 2011 Update.
Step 1: Follow the link to download WindowsPhoneDeveloperResources_[language]_patch1.msp (Windows Phone Developer Tools January 2011 Update)
Step 2: Follow the link to download VS10-KB2486994-x86.exe (Windows Phone Developer Tools Fix)

The Windows Phone Developer Tools January 2011 Update includes:

Windows Phone Emulator Update – Exposes copy/paste functionality in the Windows Phone 7 emulator. For more information, see How to: Test Copy and Paste in Windows Phone Emulator. End users can use the copy and paste functionality only after receiving the corresponding update to the Windows Phone 7 operating system.

Windows Phone Developer Resources Update – Fixes a text selection bug in pivot and panorama controls. In applications that have pivot or panorama controls that contain text boxes, users can unintentionally change panes when trying to copy text. To prevent this problem, open your application, recompile it, and then resubmit it to the Windows Phone Marketplace.

Windows Phone Capability Detection Tool – Detects the phone capabilities used by your application. When you submit your application to Windows Phone Marketplace , Microsoft performs a code analysis to detect the phone capabilities required by your application and then replaces the list of capabilities in the application manifest with the result of this detection process. This tool performs the same detection process and allows you to test your application using the same list of phone capabilities generated during the certification process. For more information, see How to: Use the Capability Detection Tool.

Windows Phone Connect Tool – Allows you to connect your phone to a PC when Zune® software is not running and debug applications that use media APIs. For more information, see How to: Use the Connect Tool.

Updated Bing Maps Silverlight Control – Includes improvements to gesture performance when using Bing™ Maps Silverlight® Control.

 

WPDT Fix includes:

Windows Phone Developer Tools Fix allowing deployment of XAP files over 64 MB in size to physical phone devices for testing and debugging.

 

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Cedar

Answer 9

将RootFrame_NavigationFailed的代码修改如下，可以实现当Page不存在时的跳转到默认Page。

其中RootFrame.Navigate(new System.Uri("/Demo;component/MainPage.xaml", System.UriKind.Relative));的代码中，Demo为MainPage.xaml所在的文件夹名称。

请注意在Windows Phone 7中文件都是以相对地址来读取的。

// Code to execute if a navigation fails
        private void RootFrame_NavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // A navigation has failed; break into the debugger
                System.Diagnostics.Debugger.Break();
            }

            e.Handled = true;

            if (RootFrame.CanGoBack)
            {
                RootFrame.GoBack();
            }
            else
            {
                RootFrame.Navigate(new System.Uri("/Demo;component/MainPage.xaml", System.UriKind.Relative));               
            }
        }

---

Cedar

Answer 10

这段代码的作用就是在Page跳转失败程序退出前，重定位Page页为MainPage.xaml,重新从MainPage开始执行

之后再次发生Page页找不到跳转失败时，执行GoBack到上一页.

---

Cedar

Answer 11

将RootFrame_NavigationFailed的代码修改如下，可以实现当Page不存在时的跳转到默认Page。

其中RootFrame.Navigate(new System.Uri("/Demo;component/MainPage.xaml", System.UriKind.Relative));的代码中，Demo为MainPage.xaml所在的文件夹名称。

请注意在Windows Phone 7中文件都是以相对地址来读取的。

// Code to execute if a navigation fails
        private void RootFrame_NavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // A navigation has failed; break into the debugger
                System.Diagnostics.Debugger.Break();
            }

            e.Handled = true;

            if (RootFrame.CanGoBack)
            {
                RootFrame.GoBack();
            }
            else
            {
                RootFrame.Navigate(new System.Uri("/Demo;component/MainPage.xaml", System.UriKind.Relative));               
            }
        }

---

Cedar

哎，还是不行，如果连接Page的路径有错的话还是如我上次所说问题，一是一步一步调试时，会无限走 System.Diagnostics.Debugger.Break();
二是直接F5会死掉；然后又如世外涛源所说换成Release，俺ctrl+F5会死几秒钟后跳到主界面……

算了，碰到类似问题还是仔细检查吧

Answer 12

调试时，一直运行System.Diagnostics.Debugger.Break();的原因是异常发生时跳转的默认页面不成功，即在此例中找不到Demo文件夹下的MainPage.xaml。

RootFrame.Navigate(new System.Uri("/Demo;component/MainPage.xaml", System.UriKind.Relative));这段代码需要中修改"/Demo;component/MainPage.xaml",将Demo改为你的工程中的存放MainPage.xaml的文件夹名称。

如果不做修改，则RootFrame找不到MainPage.xaml，还是不停的执行System.Diagnostics.Debugger

---

Cedar

Answer 13

此讨论问题的源代码下载地址

http://files.cnblogs.com/xuesong/Navigation_Demo.zip

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Cedar

Answer 14

此讨论问题的源代码下载地址

http://files.cnblogs.com/xuesong/Navigation_Demo.zip

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Cedar

嘿嘿，谢谢版主！

那个，再问个问题呗……

1：/Demo;component/MainPage.xaml     --------component是啥意思？我那个mainpage.xml就是在程序的默认目录，并没发现component目录，难道是指根目录吗？

2:为什么我从MainPage.xaml转到其它页面时如Page1.xaml(和MainPage.xaml同级) 的uri就只写"/Page1.xaml"可以了   

Answer 15

1. 如果有谁知道了，可以共享一下；

2. 在Windows Phone 7中文件都是以相对地址来读取的，因此本例中uri只写"/Page1.xaml"可以了。

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Cedar