工作中的新知识

工作中的新知识

1.有的时候我们会遇到一些可能用到缓存的时候，下面的类就是缓存类，此类涉及缓存的添加、删除、赋值还有提取。

using System;

using System.Collections.Generic; using System.Text;

namespace RCMRS.Common {

///

public class CacheManager {

private static readonly System.Web.Caching.Cache cache; static CacheManager() {

System.Web.HttpContext current = System.Web.HttpContext.Current; if (null != current) {

cache = current.Cache; } else {

cache = System.Web.HttpRuntime.Cache; } }

///

private CacheManager() {

}

///

/// 缓存的键名称 ///

public static object Get(string key) {

return cache[key]; }

///

/// 缓存的键名称 /// 缓存的值

public static void Set(string key, object value) {

Add(key, value, null); }

///

/// 索引键值 /// 缓存对象

/// 缓存依赖项 public static void Add(string key, object value, System.Web.Caching.CacheDependency dependency) {

cache.Insert(key, value, dependency, DateTime.MaxValue, TimeSpan.Zero, System.Web.Caching.CacheItemPriority.AboveNormal, null); }

///

/// 索引键值 public static void Remove(string key) {

cache.Remove(key); }

///

public static void Clear() {

System.Collections.IDictionaryEnumerator enumerator = cache.GetEnumerator();

while (enumerator.MoveNext())

{

cache.Remove(enumerator.Key.ToString()); } } } }

2.将 dataset(gridview)导出到excel的两种方法：

A．如果 没有遇到母板页的情况我们可以用以下这种方法。此方法在网上比较好查出来，但是一般不建议用此方法。 ////导出成Word文件

protected void WebToWord() {

Response.Clear();

Response.BufferOutput = true; //设定输出的字符集

Response.Charset = \"GB2312\"; //假定导出的文件名为FileName.doc

Response.AppendHeader(\"Content-Disposition\", \"attachment;filename=StuSubjectiveExam.doc\"); Response.ContentEncoding =

System.Text.Encoding.GetEncoding(\"GB2312\"); ////设置导出文件的格式

Response.ContentType = \"application/ms-word\"; //关闭ViewState

System.Globalization.CultureInfo cultureInfo = new System.Globalization.CultureInfo(\"ZH-CN\", true);

System.IO.StringWriter stringWriter = new System.IO.StringWriter(cultureInfo);

System.Web.UI.HtmlTextWriter textWriter = new System.Web.UI.HtmlTextWriter(stringWriter);

GridView4.RenderControl(textWriter); // //把HTML写回浏览器

Response.Write(stringWriter.ToString()); Response.End(); }

注释：此方法必须要在页面中写重写VerifyRenderingInServerForm的函数。 即：

public override void VerifyRenderingInServerForm(Control control) {

//注释掉下面的代码，否则在asp.net2.0下会报错

//base.VerifyRenderingInServerForm(control); }

B．此种方法是用在母板页或者上上述方法出错的情况下：

public bool DoExport(DataSet ds, string[] columns, string fileName) {

if (ds.Tables.Count == 0 || fileName == string.Empty) {

return false; }

Application excel = new ApplicationClass(); int rowindex = 1; int colindex = 0;

Workbook work = excel.Workbooks.Add(true);

//Worksheet sheet1 = (Worksheet)work.Worksheets[0]; System.Data.DataTable table = ds.Tables[0]; if (columns != null) {

for (int i = 0; i < columns.Length; i++) {

colindex++;

if (columns[i] != null && columns[i] != \"\") {

excel.Cells[1, colindex] = columns[i]; } else {

excel.Cells[1, colindex] = table.Columns[i].ColumnName; } } } else {

foreach (DataColumn col in table.Columns) {

colindex++;

excel.Cells[1, colindex] = col.ColumnName; }

}

foreach (DataRow row in table.Rows) {

rowindex++; colindex = 0;

foreach (DataColumn col in table.Columns) {

colindex++;

excel.Cells[rowindex, colindex] = row[col.ColumnName].ToString(); } }

excel.Visible = false;

excel.ActiveWorkbook.SaveAs(fileName, XlFileFormat.xlExcel9795, null, null, false, false, XlSaveAsAccessMode.xlNoChange, null, null, null, null, null);

excel.Quit(); excel = null; GC.Collect(); return true; }

注释：此方法必须要添加引用Microsoft.Office.Interop.Excel;

3.在repeater(gridview)里添加checkbox复选框，然后得到所选的内容。

A．在repeater里面添加checkbox并获值。 Html页面：

CS文件页面：得到的是所有的选择的内容

foreach (RepeaterItem ri in RepeaterSCCJ.Items) {

CheckBox cb = (CheckBox)ri.FindControl(\"CBxLSCCJ\"); if (cb.Checked) {

string sccjStr =

((System.Web.UI.HtmlControls.HtmlInputHidden)ri.FindControl(\"HiddenSCCJ\")).Value.ToString();

if (sccjStr != \"\") {

CJStr = CJStr + \"'\" + sccjStr + \"'\" + \; }

} }

if (CJStr != \"\") {

CJStr = CJStr.Substring(0, CJStr.Length - 1); }

B. 在gridview里面添加checkbox并获值。 Html页面：

BorderColor=\"White\" BorderStyle=\"None\" BorderWidth=\"1px\" Height=\"20px\" />

Cs文件页面：

foreach (GridViewRow gvr in GVFenQu.Rows) {

CheckBox cb = (CheckBox)gvr.FindControl(\"CBxFenQu\"); if (cb.Checked) {

string FenQuName =

((System.Web.UI.HtmlControls.HtmlInputHidden)gvr.FindControl(\"HiddenFenQu\")).Value.ToString();

FenQuStr = \"'\" + FenQuName + \"'\" + \ + FenQuStr; } }

if (FenQuStr != \"\") {

FenQuStr = FenQuStr.Substring(0, FenQuStr.Length - 1); }

4..NET统计用量或者别的曲线方法：

Html页面：

<%--曲线图--%>

<%--Series,绘图数据区域，实际呈现的图形形状--%>

CS页面：

Chart1.DataSource = ds.Tables[0];

Chart1.Series[\"Series1\"].XValueMember = \"抄表时间\"; Chart1.Series[\"Series1\"].YValueMembers = \"线损\"; Chart1.DataBind();

System.Web.UI.DataVisualization.Charting.Series series = Chart1.Series[\"Series1\"];

series.ToolTip = \"抄表时间 = #AXISLABEL\\n线损 = #VALY{D}\";

注释：①必须要引用using System.Web.UI.DataVisualization.Charting; 得到一个dataset对象，然后赋值给曲线控件，然后指定列就OK。

②之中学到的一个sql语句：

如果数据库中存在表TABLE则删除

if( object_id('NT1') is not null ) drop table NT1

5.在项目中添加 cookie

添加cookie：

HttpCookie myCookie = new HttpCookie(\"UserSettings\",\"bbbbbbb\"); Response.Cookies.Add(myCookie); 读取cookie：

if (HttpContext.Current.Request.Cookies[\"UserSettings\"] == null) {

Response.Write(\"CookieNonexistence\"); } else

{Response.Write(HttpContext.Current.Request.Cookies[\"UserSettings\"].Value.ToString()); }