一般我们在开发Windows Phone App，有时会需要修改锁定画面，而锁定画面的程式码又臭又长，若日後还有很多支APP需要使用到这个功能，岂不是要打很多次?所以我们何不创建一个自定义类别，将锁定画面的功能写一次就好了，日後若有其他专案使用到该功能，我们只要引入Class或Dll参考即可。
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本篇文章将引导您自制LockScreen 锁定画面类别，从【网路图片】、【Assets资源】、【UI】设定锁定画面。
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制作修改锁定画面的APP必须要先修改【WMAppManifest.xml】
参阅 :
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先看如何使用，我们可以透过【Uri】、【WriteableBitmap】、【UIElement】来操作，
Code部分相当的简短，因为我们透过自定义类别来帮我们完成了，此外也可以保持主程式的画面整洁 :
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1: //从Assets中的资源设定锁定画面
2: Uri uri = new Uri("Assets/Tiles/FlipCycleTileLarge.png", UriKind.Relative); 3: LockScreen.SetBitmap(uri);
4: ?
5: //从网路图片设定锁定画面
6: Uri uri_Net = new Uri("http://ppt.cc/vJH3", UriKind.Absolute); 7: LockScreen.SetBitmap(uri_Net);
8: ?
9: //从UI设定锁定画面
10: LockScreen.SetBitmap(LayoutRoot);
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自定义类别如下，说明一并打在程式码当中，请各位客观慢用 :
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1: public class LockScreen
2: { 3: //从Uri设定锁定画面
4: public async static void SetBitmap(Uri uri ) { 5: //若未在WMAppManifest.xml加入Extensions则结束
6: if (! await ComfirmDialog()) { 7: return;
8: }
9: //将Uri转换成Bitmap
10: BitmapImage bitmapImage = new BitmapImage();
11: bitmapImage.CreateOptions = BitmapCreateOptions.None;
12: bitmapImage.UriSource = uri;
13: bitmapImage.ImageOpened += (s, e) =>
14: { 15: //载入完成，必须要等到BitmapImage载入完成才能继续，否则等於白做
16: WriteableBitmap wbm = new WriteableBitmap((BitmapImage)s);
17: //将Bitmap转换成WriteableBitmap
18: Uri uri_Net = new Uri(WriteImageToFile(new WriteableBitmap(wbm)), UriKind.Absolute);
19: //设定锁定画面
20: Windows.Phone.System.UserProfile.LockScreen.SetImageUri(uri_Net);
21: };
22: }
23: //从WriteableBitmap设定锁定画面
24: public async static void SetBitmap(WriteableBitmap writeableBitmap)
25: { 26: //若未在WMAppManifest.xml加入Extensions则结束
27: if (!await ComfirmDialog())
28: { 29: return;
30: }
31: Uri uri_UI = new Uri(WriteImageToFile(writeableBitmap), UriKind.Absolute);
32: Windows.Phone.System.UserProfile.LockScreen.SetImageUri(uri_UI);
33: }
34: ?
35: //从UIElement设定锁定画面
36: public async static void SetBitmap(UIElement uielement)
37: { 38: //若未在WMAppManifest.xml加入Extensions则结束
39: if (!await ComfirmDialog())
40: { 41: return;
42: }
43: Uri uri_UI = new Uri(WriteImageToFile(new WriteableBitmap(uielement, null)), UriKind.Absolute);
44: Windows.Phone.System.UserProfile.LockScreen.SetImageUri(uri_UI);
45: }
46: ?
47: //判断该APP是否已向系统申请修改锁定画面，若为False则未在WMAppManifest.xml加入Extensions
48: public async static TaskComfirmDialog(){
49: try
50: { 51: var isProvider = Windows.Phone.System.UserProfile.LockScreenManager.IsProvidedByCurrentApplication;
52: //若尚未申请
53: if (!isProvider)
54: { 55: //跳出视窗询问使用者，是否授权该APP可以修改锁定画面
56: var op = await Windows.Phone.System.UserProfile.LockScreenManager.RequestAccessAsync();
57: isProvider = op == Windows.Phone.System.UserProfile.LockScreenRequestResult.Granted;
58: }
59: return true;
60: }
61: catch
62: { 63: Debug.WriteLine("请在WMAppManifest.xml加入Extensions"); 64: Debug.WriteLine("参阅 : http://ppt.cc/5U07"); 65: return false;
66: }
67: }
68: ?
69: //档案写入Isolate 回传 Uri路径
70: private static string WriteImageToFile(WriteableBitmap writeable_bitmap)
71: { 72: //档名A
73: string FileNameA = "/LockScreen/A.jpg";
74: //档名B
75: string FileNameB = "/LockScreen/B.jpg";
76: //最後使用的党名
77: string FileName = "";
78: try
79: { 80: ?
81: using (IsolatedStorageFile tStorage = IsolatedStorageFile.GetUserStoreForApplication())
82: { 83: //宣告存取IsolatedStorageFile的变数
84: var isolatedStorage = IsolatedStorageFile.GetUserStoreForApplication();
85: ?
86: //若为第一次A、B都不存在
87: if (!isolatedStorage.FileExists(FileNameA) && !isolatedStorage.FileExists(FileNameB))
88: { 89: //使用其中一个当作档名
90: FileName = FileNameA;
91: }
92: //若A存在则使用B名称来当作写入的档名
93: if (isolatedStorage.FileExists(FileNameA))
94: { 95: //删除A
96: isolatedStorage.DeleteFile(FileNameA);
97: //使用档名B
98: FileName = FileNameB;
99: }
100: //若B存在则使用A名称来当作写入的档名
101: if (isolatedStorage.FileExists(FileNameB))
102: { 103: //删除B
104: isolatedStorage.DeleteFile(FileNameB);
105: //使用档名A
106: FileName = FileNameA;
107: }
108: ?
109: //在独立存储区创建档案
110: IsolatedStorageFileStream fileStream = isolatedStorage.CreateFile(FileName);
111: //写入JPG图档，品质为100 (越低图片画质就越低)
112: writeable_bitmap.SaveJpeg(fileStream, writeable_bitmap.PixelWidth, writeable_bitmap.PixelHeight, 0, 100);
113: //关闭IO
114: fileStream.Close();
115: fileStream.Dispose();
116: tStorage.Dispose();
117: ?
118: }
119: //重组新的URI，并回传
120: return string.Format("ms-appdata:///local/{0}", FileName); 121: }
122: catch (Exception ex)
123: { 124: string tMsg = ex.Message;
125: return string.Empty;
126: }
127: }
128: ?
129: }
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如此一来我们就自制LockScreen 锁定画面类别(Class)，从【网路图片】、【Assets资源】、【UI】修改锁定画面罗!
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References :
Suki统整出来的自定义类别
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文章中的叙述如有观念不正确错误的部分，欢迎告知指正 谢谢
转载请注明出处，并且附上本篇文章网址 !? 感谢。 SUKI
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