C＃代码更改锁屏并将文件分配给IStorage

问题描述

嗨
我想从wpf应用程序更改Windows 8锁屏。



我想出了从.netcore使用lockscreen类的方法，但这些方法需要IStorage作为参数。

我是c＃的新手，我不知道如何将文件分配给Istorage。



如何加载文件Istorage变量???



谢谢

HiI want to change Windows 8 lockscreen from wpf application.

I figured out way to use lockscreen class from .netcore but those methods take IStorage as arguments.
I am new to c# and I dont know how to assign files to Istorage.

How can I load file in Istorage variable???

Thank You

推荐答案

using SDKTemplate;
using System;
using Windows.Storage;
using Windows.Storage.Pickers;
using Windows.Storage.Streams;
using Windows.System.UserProfile;

private async void SetLockScreen()
{
    rootPage.NotifyUser("", NotifyType.StatusMessage); 
    FileOpenPicker imagePicker = new FileOpenPicker 
    { 
       ViewMode = PickerViewMode.Thumbnail, 
       SuggestedStartLocation = PickerLocationId.PicturesLibrary, 
       FileTypeFilter = { ".jpg", ".jpeg", ".png", ".bmp" } 
     }; 
 
     StorageFile imageFile = await imagePicker.PickSingleFileAsync(); 
     if (imageFile != null) 
     { 
         try 
         { 
            // Application now has access to the picked file, setting image to lockscreen.  This will fail if the file is an invalid format. 
            await LockScreen.SetImageFileAsync(imageFile); 
 
            // Retrieve the lock screen image that was set 
            IRandomAccessStream imageStream = LockScreen.GetImageStream(); 
            if (imageStream != null) 
            { 
               BitmapImage lockScreen = new BitmapImage(); 
               lockScreen.SetSource(imageStream); 
               LockScreenImage.Source = lockScreen; 
               LockScreenImage.Visibility = Visibility.Visible; 
             } 
             else 
             { 
               LockScreenImage.Visibility = Visibility.Collapsed; 
               rootPage.NotifyUser("Setting the lock screen image failed.  Make sure your copy of Windows is activated.", NotifyType.StatusMessage); 
             } 
           } 
           catch (Exception) 
           { 
               LockScreenImage.Visibility = Visibility.Collapsed; 
               rootPage.NotifyUser("Invalid image selected or error opening stream.", NotifyType.ErrorMessage); 
           } 
    } 
    else 
    { 
         LockScreenImage.Visibility = Visibility.Collapsed; 
         rootPage.NotifyUser("No file was selected using the picker.", NotifyType.StatusMessage); 
    }
}

请注意，使用新Win 8 API的Windows 8应用程序只能访问计算机上先前定义的位置列表。可以在 []。无论如何，如果您现在想要打开位于应用程序基目录中的文件，则需要使用以下行替换文件夹选择器：

Please not that Windows 8 Apps which are using the new Win 8 API are only capable of accesing a previously defined list of locations on your computer. The list of currently accesible directories can be found at the MSDN[^]. Whatsoever, if you now would like to open a file located in your applications base directory, you would need to replace the folder picker with the following lines:

StorageFolder storageFolder = KnownFolders.DocumentsLibrary;
StorageFile file = await storageFolder.GetFileAsync("yourdesiredimage.jpg");

这会让你的代码看起来像这样：

this would lead to let your code look somewhat like this:

using SDKTemplate;
using System;
using Windows.Storage;
using Windows.Storage.Pickers;
using Windows.Storage.Streams;
using Windows.System.UserProfile;

private async void SetLockScreen()
{
    rootPage.NotifyUser("", NotifyType.StatusMessage); 
    StorageFolder storageFolder = KnownFolders.DocumentsLibrary;
    StorageFile imageFile= await storageFolder.GetFileAsync("yourdesiredimage.jpg");
 
     if (imageFile != null) 
     { 
         try 
         { 
            // Application now has access to the picked file, setting image to lockscreen.  This will fail if the file is an invalid format. 
            await LockScreen.SetImageFileAsync(imageFile); 
 
            // Retrieve the lock screen image that was set 
            IRandomAccessStream imageStream = LockScreen.GetImageStream(); 
            if (imageStream != null) 
            { 
               BitmapImage lockScreen = new BitmapImage(); 
               lockScreen.SetSource(imageStream); 
               LockScreenImage.Source = lockScreen; 
               LockScreenImage.Visibility = Visibility.Visible; 
             } 
             else 
             { 
               LockScreenImage.Visibility = Visibility.Collapsed; 
               rootPage.NotifyUser("Setting the lock screen image failed.  Make sure your copy of Windows is activated.", NotifyType.StatusMessage); 
             } 
           } 
           catch (Exception) 
           { 
               LockScreenImage.Visibility = Visibility.Collapsed; 
               rootPage.NotifyUser("Invalid image selected or error opening stream.", NotifyType.ErrorMessage); 
           } 
    } 
    else 
    { 
         LockScreenImage.Visibility = Visibility.Collapsed; 
         rootPage.NotifyUser("No file was selected using the picker.", NotifyType.StatusMessage); 
    }
}

在回复此解决方案的评论时，使用硬编码的完整路径作为 C：\ Temp \Img.jpeg被认为是错误的编码实践，应该尽可能避免。特别是Windows 8，还有Windows 7和Vista有一种方法可以通过使用框架枚举或直接访问本地计算机变量（例如％APPDATA％）直接访问文件夹来获取文件夹的路径。

In reply to a comment on this solution, using hard-coded full paths as "C:\Temp\Img.jpeg" is considered bad coding practice and should be avoided whenever possible. Especially Windows 8, but also Windows 7 and Vista have a way to directly access a folder by either using a framework enumeration or accessing local computer variables (such as %APPDATA%) directly to get the path of a folder.

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