对象持久化是指将内存中的对象保存到可永久保存的存储设备中（如磁盘）的一种技术。
本文介绍的是除数据库之外的几种对象持久化方式。
具体如下：
涉及知识点：
如下图所示【主要功能是将用户输入的信息保存成各种格式，并从各个文档中进行读取出来】：
保存和读取文本文档代码如下：
/// <summary>
/// 保存成文本
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnSaveTxt_Click(object sender, EventArgs e)
{
Dictionary<string, string> dicInfos = GetDictionaryInfos();
string filePath = "objPerson.txt";
//采用using关键字，会自动释放
using (FileStream fs = new FileStream(filePath, FileMode.Create))
{
using (StreamWriter sw = new StreamWriter(fs, Encoding.Default))
{
foreach (var keyPair in dicInfos)
{
sw.WriteLine(string.Format("{0}={1}", keyPair.Key, keyPair.Value));
}
}
}
}
/// <summary>
/// 从文本中读取
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnReadTxt_Click(object sender, EventArgs e)
{
string filePath = "objPerson.txt";
Dictionary<string, string> dic = new Dictionary<string, string>();
//采用using关键字，会自动释放
using (FileStream fs = new FileStream(filePath, FileMode.Open))
{
using (StreamReader sw = new StreamReader(fs, Encoding.Default))
{
while (!sw.EndOfStream) {
string lineInfo = sw.ReadLine();
dic.Add(lineInfo.Split('=')[0], lineInfo.Split('=')[1]);
}
}
}
this.txtName.Text = dic["Name"];
this.dtBirthday.Text = dic["Birthday"];
if (dic["Gender"] == this.rbBoy.Text)
{
this.rbBoy.Checked = true;
}
else {
this.rbGirl.Checked = true;
}
string[] loves = dic["Love"].Split('|');
foreach (var love in loves)
{
foreach (var item in this.lsvLove.Items)
{
ListViewItem li = item as ListViewItem;
if (li.Text == love)
{
li.Checked = true;
}
}
}
}
保存和读取Xml文档代码如下：
/// <summary>
/// 保存成Xml
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnSaveXml_Click(object sender, EventArgs e)
{
Person p = GetPersonInfos();
string filePath = "objPerson.xml";
using (FileStream fs = new FileStream(filePath, FileMode.Create))
{
XmlSerializer serializer = new XmlSerializer(typeof(Person));
serializer.Serialize(fs, p);
}
}
/// <summary>
/// 从Xml中读取
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnReadXml_Click(object sender, EventArgs e)
{
string filePath = "objPerson.xml";
Person p;
using (FileStream fs = new FileStream(filePath, FileMode.Open))
{
XmlSerializer serializer = new XmlSerializer(typeof(Person));
object obj= serializer.Deserialize(fs);
p = obj as Person;
}
SetPersonInfos(p);
}
保存和读取Json文档如下：
/// <summary>
/// 保存成Json
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnSaveJson_Click(object sender, EventArgs e)
{
Person p = GetPersonInfos();
JavaScriptSerializer jserializer = new JavaScriptSerializer();
string strJson = jserializer.Serialize(p);
string strRegex = @"\\/Date\((\d+)\)\\/";
MatchEvaluator evaluator = new MatchEvaluator(ConvertJsonDateToDateString);
//对时间进行处理，需要引用System.Text.RegularExpressions;命名空间
Regex reg = new Regex(strRegex);
strJson = reg.Replace(strJson, evaluator);
string filePath = "objPerson.json";
using (FileStream fs = new FileStream(filePath, FileMode.Create))
{
using (StreamWriter sw = new StreamWriter(fs, Encoding.Default))
{
sw.Write(strJson);
}
}
}
/// <summary>
/// 从Json中读取
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnReadJson_Click(object sender, EventArgs e)
{
JavaScriptSerializer jserializer = new JavaScriptSerializer();
string filePath = "objPerson.json";
Person p;
using (FileStream fs = new FileStream(filePath, FileMode.Open))
{
using (StreamReader sw = new StreamReader(fs, Encoding.Default))
{
string strJson = sw.ReadToEnd();
string strRegex = @"\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2}";
MatchEvaluator evaluator = new MatchEvaluator(ConvertDateStringToJsonDate); //对时间进行处理
Regex reg = new Regex(strRegex);
strJson = reg.Replace(strJson, evaluator);
p = jserializer.Deserialize<Person>(strJson);
}
}
SetPersonInfos(p);
}
保存和读取Bin文档如下：
/// <summary>
/// 保存成二进制文件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnSaveBin_Click(object sender, EventArgs e)
{
Person p = GetPersonInfos();
string filePath = "objPerson.bin";
using (FileStream fs = new FileStream(filePath, FileMode.Create)) {
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(fs, p);
}
}
/// <summary>
/// 读取二进制文件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnReadBin_Click(object sender, EventArgs e)
{
string filePath = "objPerson.bin";
Person p;
using (FileStream fs = new FileStream(filePath, FileMode.Open))
{
BinaryFormatter bf = new BinaryFormatter();
p= bf.Deserialize(fs) as Person;
}
SetPersonInfos(p);
}
备注：其实对象持久化和对象序列化是两个不同的概念。两者有关联却不同。
对象持久化：是使对象可以保存到实体存储介质中，在对象生命周期结束后可以再现。
对象序列化：是将对象或者数据结构转化成特定的格式，使其可在网络中传输，或者可存储在内存或者文件中。
以上就是本文的全部内容，希望本文的内容对大家的学习或者工作能带来一定的帮助，同时也希望多多支持脚本之家！
