WP8 独立存储 总结2

wp7.1APIs

Isolated Storage Classes

•独立存储类在System.IO.IsolatedStorage命名空间中
•IsolatedStorageFile
•表示包含文件和目录的独立存储区
•IsolatedFileStream
•公开独立存储中的文件

Saving Data代码

private void saveGameToIsolatedStorage(string message)
{
　　using(IsolatedStorageFile isf =
　　IsolatedStorageFile.GetUserStoreForApplication())
　　{
　　　　using(IsolatedStorageFileStreamrawStream= isf.CreateFile("MyFile.store"))
　　　　{
　　　　　　StreamWriterwriter = newStreamWriter(rawStream);
　　　　　　writer.WriteLine(message); // save the message
　　　　　　writer.Close();
　　　　}
  　}
}

Loading Data 代码

 1 private string loadString()
 2 {
 3     stringresult = null;
 4     using(IsolatedStorageFileisf = IsolatedStorageFile.GetUserStoreForApplication())
 5     {
 6         if(isf.FileExists("Myfile.store")
 7     　　{
 8     　　　　using(IsolatedStorageFileStreamrawStream = isf.OpenFile(filename, System.IO.FileMode.Open))
 9          　　　　{　　　　　　　　　　　　　　StreamReaderreader = newStreamReader(rawStream);
10 　　　　　　　　　　　　result = reader.ReadLine();
11 　　　　　　　　　　reader.Close();
12 　　　　　　　　　　} 　　　　　　}
13 　　 }
14 　　 return result;
15 }        

例如在 AddPade.xaml.cs 上加入以下代码

 1 namespace PhoneApp1
 2 {
 3     public partial class AddPage : PhoneApplicationPage
 4     {
 5         public AddPage()
 6         {
 7             InitializeComponent();
 8         }
 9         protected override void OnNavigatedTo(NavigationEventArgs e)
10         {
11             base.OnNavigatedTo(e);
12             if (this.State.ContainsKey("IncompleteEntry"))
13             {
14                 this.logtext.Text = this.State["IncompleteEntry"] as string;
15             }
16         }
17         protected override void OnNavigatedFrom(NavigationEventArgs e)
18         {
19             if (e.NavigationMode != System.Windows.Navigation.NavigationMode.Back &&
20                 e.NavigationMode != System.Windows.Navigation.NavigationMode.Forward)
21             {
22                 this.State["IncompleteEntry"] = this.logtext.Text;
23             }
24             base.OnNavigatedFrom(e);
25         }
26
27
28         private void ApplicationBarIconButton_Click(object sender, EventArgs e)
29         {
30             SaveEntry();
31
32
33             if (NavigationService.CanGoBack)
34             {
35                 NavigationService.GoBack();
36             }
37         }
38
39
40         private void cancel_Click(object sender, EventArgs e)
41         {
42             if (NavigationService.CanGoBack)
43             {
44                 NavigationService.GoBack();
45             }
46         }
47
48
49         private async void SaveEntry()
50         {
51             string timeshow = System.DateTime.Now + System.Environment.NewLine;
52
53
54             App thisapp = App.Current as App;//利用APP属性传递值
55
56
57             thisapp.logdata = FileStorageOperation.LoadFromIsolatedStorage();
58             thisapp.logdata = thisapp.logdata + timeshow + logtext.Text + System.Environment.NewLine;
59             FileStorageOperation.SavetoIsolatedStorage(thisapp.logdata);
60
61
62         }
63     }
64 }  

在APP.XAML.CS加入属性的值

1 public string logdata
2         {
3             set;
4             get;
5         }

在显示的页面的代码加入

 1 protected override void OnNavigatedTo(NavigationEventArgs e)
 2         {
 3             base.OnNavigatedTo(e);
 4
 5
 6
 7             App thisapp = App.Current as App;
 8
 9
10             thisapp.logdata = FileStorageOperation.LoadFromIsolatedStorage();
11
12
13             showblock.Text = thisapp.logdata;
14         }