在项目中常常常使用到DataTable,假设DataTable使用得当，不仅能使程序简洁有用，并且可以提高性能，达到事半功倍的效果，现对DataTable的使用技巧进行一下总结。
添加引用
using System.Data;
创建表
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C#DataTable使用2023-03-16 21:36:12
HTTP GET POST 获取2023-03-14 17:46:04
public class WebHttp
{
/// <summary>
/// get请求带重试
/// </summary>
/// <param name="Url"></param>
/// <param name="postDataStr"></param>
/// <param name="sum"></param>
/// <returns></returns>
public static string HttpGet(string Url, string postDataStr, int sum)
{
string temp=null;
for (int i = 0; i < sum; i++)
{
if (string.IsNullOrEmpty(temp) || string.IsNullOrEmpty(temp.Trim()))
{
temp = HttpGet(Url, postDataStr);
}
else {
break;
}
}
return temp;
}
/// <summary>
/// post请求带重试
/// </summary>
/// <param name="Url"></param>
/// <param name="postDataStr"></param>
/// <param name="sum"></param>
/// <returns></returns>
public static string HttpPost(string Url, string postDataStr, int sum)
{
string temp = null;
for (int i = 0; i < sum; i++)
{
if (string.IsNullOrEmpty(temp) || string.IsNullOrEmpty(temp.Trim()))
{
temp = HttpPost(Url, postDataStr);
}
else
{
break;
}
}
return temp;
}
/// <summary>
/// GET请求与获取结果
/// </summary>
public static string HttpGet(string Url, string postDataStr)
{
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url + (postDataStr == "" ? "" : "?") + postDataStr);
request.Method = "GET";
request.ContentType = "text/html;charset=UTF-8";
request.Timeout = 10000;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream myResponseStream = response.GetResponseStream();
StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.UTF8);
string retString = myStreamReader.ReadToEnd();
myStreamReader.Close();
myResponseStream.Close();
return retString;
}
catch (Exception ex)
{
return null;
}
}
/// <summary>
/// POST请求与获取结果
/// </summary>
public static string HttpPost(string Url, string postDataStr)
{
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
request.Method = "POST";
request.Timeout = 6000000;
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = postDataStr.Length;
StreamWriter writer = new StreamWriter(request.GetRequestStream(), Encoding.ASCII);
writer.Write(postDataStr);
writer.Flush();
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
string encoding = response.ContentEncoding;
if (encoding == null || encoding.Length < 1)
{
encoding = "UTF-8"; //默认编码
}
StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(encoding));
string retString = reader.ReadToEnd();
return retString;
}
catch (Exception ex)
{
return null;
}
}
}C#【多线程篇】BackgroundWorker类使用总结2023-03-14 17:44:42
using System;
using System.ComponentModel;
using System.Windows.Forms;
namespace WindowsFormsApp1
{
public partial class Form1 : Form
{
private BackgroundWorker bgWorker = new BackgroundWorker();
public Form1()
{
InitializeComponent();
InitializeBackgroundWorker();
}
private void InitializeBackgroundWorker()
{
bgWorker.WorkerReportsProgress = true;
bgWorker.WorkerSupportsCancellation = true;
bgWorker.DoWork += new DoWorkEventHandler(bgWorker_DoWork);
bgWorker.ProgressChanged += new ProgressChangedEventHandler(bgWorker_ProgessChanged);
bgWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bgWorker_WorkerCompleted);
}
public void bgWorker_DoWork(object sender, DoWorkEventArgs e)
{
for (int i = 0; i <= 100; i++)
{
if (bgWorker.CancellationPending)
{
e.Cancel = true;
return;
}
else
{
bgWorker.ReportProgress(i, "Working");
System.Threading.Thread.Sleep(10);
}
}
}
public void bgWorker_ProgessChanged(object sender, ProgressChangedEventArgs e)
{
string state =(string)e.UserState;//接收ReportProgress方法传递过来的userState
this.label2.Text = "状态:" +state;
this.progressBar1.Value = e.ProgressPercentage;
this.label1.Text = "处理进度:" + Convert.ToString(e.ProgressPercentage) + "%";
}
public void bgWorker_WorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
if (e.Error != null)
{
MessageBox.Show(e.Error.ToString());
return;
}
if (!e.Cancelled)
this.label1.Text = "处理完毕!";
else
this.label1.Text = "处理终止!";
}
private void btnStart_Click_1(object sender, EventArgs e)
{
if (bgWorker.IsBusy)
return;
this.progressBar1.Maximum = 100;
this.btnStart.Enabled = false;
this.btnStop.Enabled = true;
bgWorker.RunWorkerAsync("hello");
}
private void btnStop_Click_1(object sender, EventArgs e)
{
this.btnStart.Enabled = true;
this.btnStop.Enabled = false;
bgWorker.CancelAsync();
}
}
}C#判断对象是否有值2023-03-14 17:40:40
//封装为一个方法判断变量是否为空
isobjEmpty(obj) {
if (obj === null || obj === undefined || obj === "" || obj.length === 0 || obj === {}) {
return true;
} else {
return false;
}
},
//使用
if(!this.isobjEmpty(obj)){
//存在
}else{
//不存在
}C# 从json中判断某个属性是否存在2023-03-14 17:39:01
if (jo.Property("abc") != null)
{
}C#实现程序的版本升级更新2022-12-03 12:20:53
我们做了程序，不免会有版本升级，这就需要程序有自动版本升级的功能。
那么看看我是如何实现程序自动更新的。
直接上代码：
using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;
using System.IO;
using System.Net;
using System.Xml;
namespace Update
{
/// <summary>
/// 更新完成触发的事件
/// </summary>
public delegate void UpdateState();
/// <summary>
/// 程序更新
/// </summary>
public class SoftUpdate
{
private string download;
private const string updateUrl = "http://www.csdn.net/update.xml";//升级配置的XML文件地址
#region 构造函数
public SoftUpdate() { }
/// <summary>
/// 程序更新
/// </summary>
/// <param name="file">要更新的文件</param>
public SoftUpdate(string file,string softName) {
this.LoadFile = file;
this.SoftName = softName;
}
#endregion
#region 属性
private string loadFile;
private string newVerson;
private string softName;
private bool isUpdate;
/// <summary>
/// 或取是否需要更新
/// </summary>
public bool IsUpdate
{
get
{
checkUpdate();
return isUpdate;
}
}
/// <summary>
/// 要检查更新的文件
/// </summary>
public string LoadFile
{
get { return loadFile; }
set { loadFile = value; }
}
/// <summary>
/// 程序集新版本
/// </summary> % 3B
public string NewVerson
{
get { return newVerson; }
}
/// <summary>
/// 升级的名称
/// </summary>
public string SoftName
{
get { return softName; }
set { softName = value; }
}
#endregion
/// <summary>
/// 更新完成时触发的事件
/// </summary>
public event UpdateState UpdateFinish;
private void isFinish() {
if(UpdateFinish != null)
UpdateFinish();
}
/// <summary>
/// 下载更新
/// </summary>
public void Update()
{
try
{
if (!isUpdate)
return;
WebClient wc = new WebClient();
string filename = "";
string exten = download.Substring(download.LastIndexOf("."));
if (loadFile.IndexOf(@"\") == -1)
filename = "Update_" + Path.GetFileNameWithoutExtension(loadFile) + exten;
else
filename = Path.GetDirectoryName(loadFile) + "\\Update_" + Path.GetFileNameWithoutExtension(loadFile) + exten;
wc.DownloadFile(download, filename);
wc.Dispose();
isFinish();
}
catch
{
throw new Exception("更新出现错误，网络连接失败！");
}
}
/// <summary>
/// 检查是否需要更新
C#读写config配置文件 2020-12-22 11:35:06
应用程序配置文件（App.config）是标准的 XML 文件，XML 标记和属性是区分大小写的。它是可以按需要更改的，开发人员可以使用配置文件来更改设置，而不必重编译应用程序。对于一个config文件：<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
&nbs
c#在一个窗口中打开另一个窗口2020-12-22 11:33:07
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C#使用checkedListBox1控件链接数据库的方法示例2020-12-22 11:26:59
本文实例讲述了C#使用checkedListBox1控件链接数据库的方法。分享给大家供大家参考，具体如下：在数据库中创建三个表: 学生信息表 爱好表 学生爱好表 结果让学生的信息和爱好同时显示到C#窗体上面using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using S
C#将datatable数据转换成JSON数据的方法2020-06-27 15:09:07
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