Silverlight Isolated Storage 独立存储-蒲公英云

Silverlight Isolated Storage 独立存储

Silverlight 独立存储好比Cookie一样，可以在客户端存储信息，但是他更加强大，独立存储提供了客户端指定目录下的读写权限，可以任意的向其中添加删除修改读取文件。

独立存储将文件存储在系统盘-当前用户-本地的-指定文件夹当中。

独立存储有两个作用域应用程序级别和站点级别他就像是一个为Silverlight专门提供的文件夹，用来存放Silverlight的文件信息，比如XML、TXT、Dat、Html等，格式不限只要对你有用。

#

基础操作语法

using System.IO.IsolatedStorage;
using System.IO;
void CreateDir(string dirName)
       {
           IsolatedStorageFile storeFile =
               IsolatedStorageFile.GetUserStoreForApplication();
           storeFile.CreateDirectory(dirName);
       }
       void SaveFile(string savePath, string content)
       {
           IsolatedStorageFile storeFile =
               IsolatedStorageFile.GetUserStoreForApplication();
           IsolatedStorageFileStream sf = storeFile.CreateFile(savePath);
           using (StreamWriter sw = new StreamWriter(sf))
           {
               sw.WriteLine(content);
           }
           sf.Close();
       }
       void LoadFile(string readPath)
       {
           string content = string.Empty;
           using (IsolatedStorageFile storeFile =
               IsolatedStorageFile.GetUserStoreForApplication())
           {
               if (storeFile.FileExists(readPath))
               {
                   StreamReader sr =
                       new StreamReader(storeFile.OpenFile
                           (readPath, FileMode.Open, FileAccess.Read));
                   content = sr.ReadToEnd();
               }
           }
       }
       void DeleteFile(string path)
       {
           using (IsolatedStorageFile storeFile =
               IsolatedStorageFile.GetUserStoreForApplication())
           {
               storeFile.DeleteFile(path);
           }
       }
       void DeleteDir(string dirPath)
       {
           using (IsolatedStorageFile storeFile =
               IsolatedStorageFile.GetUserStoreForApplication())
           {
               storeFile.DeleteDirectory(dirPath);
           }
       }
       void LoadDirs()
       {
           using (IsolatedStorageFile storeFile =
               IsolatedStorageFile.GetUserStoreForApplication())
           {
               var itemSource = storeFile.GetDirectoryNames("*");
           }
       }

名值对方式存储读取

这种方式就很像Cookie了
string ReadSettings(string key)
       {
           IsolatedStorageSettings settings =
               IsolatedStorageSettings.ApplicationSettings;
           return settings[key].ToString();
       }
       void SaveSettings(string key, string value)
       {
           IsolatedStorageSettings settings =
               IsolatedStorageSettings.ApplicationSettings;
           settings.Add(key, value);
           settings.Save();
       }
       void ClearSettings()
       {
           IsolatedStorageSettings settings =
               IsolatedStorageSettings.ApplicationSettings;
           settings.Clear();
       }

独立存储的文件与名值对分别有两个示例，可以在目录地址链接下载代码阅读。

独立存储的空间大小

独立存储默认的空间上限是1M，可以通过代码设置让这个上限加大。代码如下

//使1用?应|用?程ì序ò存?储￠创′建¨对?象ó
            using (IsolatedStorageFile storeFile =
                IsolatedStorageFile.GetUserStoreForApplication())
            {
                //获?取?旧é空?间?大ó小?
                long oldSize = storeFile.AvailableFreeSpace;
                //定¨义?新?增?空?间?大ó小?
                long newSize = 2097152;
                if (oldSize < newSize)
                {
                    //分?配?新?的?存?储￠空?间?
                    storeFile.IncreaseQuotaTo(newSize);
                }
            }