ios 临时存储 临时存储数据

用户登录 记住账号密码，用二进制方式存储临时数据；其实可以记住任何对象。

 

1、首先，需要一个可访问的存储位置 -- 本地临时目录：

// 这两句找到当前用户的临时文件目录
string _temp = System.Environment.GetEnvironmentVariable("TEMP");
DirectoryInfo info = new DirectoryInfo(_temp);
info.FullName // 这是临时目录

方法：

1 /// <summary>
 2 /// 临时文件目录
 3 /// </summary>
 4 /// <param name="tempPath">临时文件位置</param>
 5 /// <param name="filename">临时文件名</param>
 6 /// <returns>文件路径</returns>
 7 private string TempPath(string tempPath,string filename)
 8 {
 9     // 这两句找到当前用户的临时文件目录
10     string _temp = System.Environment.GetEnvironmentVariable("TEMP");
11     DirectoryInfo info = new DirectoryInfo(_temp);
12 
13     string db_path = string.Format("{0}{1}", info.FullName, tempPath);
14     // 如果文件不存在则创建
15     if (!Directory.Exists(db_path))
16     {
17         Directory.CreateDirectory(db_path);
18     }
19     string db_file = string.Format("{0}\\{1}", db_path, filename);
20     return db_file;
21 }

 

2、然后，写入文件

1 /// <summary>
 2 /// 写入文件
 3 /// </summary>
 4 /// <typeparam name="T">泛型对象</typeparam>
 5 /// <param name="key">存储Key</param>
 6 /// <param name="db_file_path">存储文件路径</param>
 7 /// <param name="content">存储内容</param>
 8 /// <param name="isremember">是否记录</param>
 9 private void WritBin<T>(string key, string db_file_path, T content, bool isremember)
10 {
11     Dictionary<string, T> cs = new Dictionary<string, T>();
12 
13     FileStream fs = new FileStream(db_file_path, FileMode.OpenOrCreate);
14     try
15     {
16         BinaryFormatter bf = new BinaryFormatter();
17 
18         //选在集合中是否存在用户名 
19         if (cs.ContainsKey(key))
20         {
21             //如果有清掉
22             cs.Remove(key);
23         }
24         //添加用户信息到集合
25         if (isremember)
26         {
27             cs.Add(key, content);
28         }
29         
30         //写入文件
31         bf.Serialize(fs, cs);
32     }
33     finally
34     {
35         //关闭
36         fs.Close();
37         fs.Dispose();
38     }
39 }

3、接着读取文件内容：

1 /// <summary>
 2 /// 读取Bin
 3 /// </summary>
 4 /// <typeparam name="T"></typeparam>
 5 /// <param name="path"></param>
 6 /// <returns></returns>
 7 private List<T> ReadBin<T>(string path)
 8 {
 9     //读取文件流对象
10     List<T> list = new List<T>();
11     Dictionary<string, T> cs = new Dictionary<string, T>();
12 
13     //读取文件流对象
14     FileStream fs = new FileStream(path, FileMode.OpenOrCreate);
15     try
16     {
17         if (fs.Length > 0)
18         {
19             BinaryFormatter bf = new BinaryFormatter();
20             //读出存在Data.bin 里的用户信息
21             cs = bf.Deserialize(fs) as Dictionary<string, T>;
22 
23             list = cs.Values.ToList();
24            
25         }
26         return list;
27     }
28     finally
29     {
30         fs.Close();
31         fs.Dispose();
32     }
33 }

 

4、以上都是私有方法，需要两个公共方法提供调用

1 /// <summary>
 2 /// 读取bin内容
 3 /// </summary>
 4 /// <typeparam name="T"></typeparam>
 5 /// <param name="path"></param>
 6 /// <returns></returns>
 7 public List<T> GetListBinValues<T>(string path,string filename)
 8 {
 9     try
10     {
11         var fp = TempPath(path, filename);
12         return ReadBin<T>(fp);
13     }
14     catch (Exception ex)
15     {
16         throw new Exception(ex.Message);
17     }
18 }
19 
20 /// <summary>
21 /// 写入值
22 /// </summary>
23 /// <typeparam name="T">泛型对象</typeparam>
24 /// <param name="path">位置路径 （本来临时目录下的文件夹相对路径）</param>
25 /// <param name="filename">文件名</param>
26 /// <param name="isremember">是否存储</param>
27 /// <param name="key">存储key</param>
28 /// <param name="content">存储内容</param>
29 public void AddListBinValues<T>(string path,string filename,bool isremember,string key, T content)
30 {
31     try
32     {
33         var fp = TempPath(path, filename);
34 
35         WritBin<T>(key,fp, content, isremember);
36     }
37     catch (Exception ex)
38     {
39         throw new Exception(ex.Message);
40     }
41     
42 }

 5、最后 封装到类里

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization.Formatters.Binary;

namespace TempService
{
    public class DBbin
    {
         // 添加以上方法
    }
}

 

---

 

调用实例

写入：

DBbin _DBbin = new DBbin();

remberUser vm = new remberUser();
vm.username = _loginName;
vm.password = _pwd;

_DBbin.AddListBinValues(remberpath, remberfile, _isRe, _loginName, vm);

读取值：

DBbin _DBbin = new DBbin();
var users = _DBbin.GetListBinValues<remberUser>(remberpath, remberfile);

 

***注意事项***

[Serializable]要注明需要存储的对象是可序列化的，不然会报错

/// <summary>
/// 用户名密码记录
/// </summary>
[Serializable]
public class remberUser
{
    public string username { get; set; }

    public string password { get; set; }
}