使用 C# 语言编写字符串常量的时候,你可能会发现可以使用 "" 而不能使用 string.Empty。...进一步可以发现 string.Empty 实际上是一个静态只读字段,而不是一个常量。 为什么这个看起来最适合是常量的 string.Empty,竟然使用静态只读字段呢?...---- string.Empty 这个问题,我们需要去看 .NET Core 的源码(当然 .NET Framework 也是一样的)。...也就是说,string.Empty 字段并不是一个普通的字段,对它的调用会被特殊处理。但是是如何特殊处理呢?...本文引申的其他问题 能否反射修改 string.Empty 的值? 不行!
结果如下: 两种赋值方式的比较: string str=""; string str=string.Empty; 理论上讲: string.Empty是一个Static的属性,使用时不分配存储空间...""; } } public void testEqualEmpty() { string str; for (int i = 0; i < 10000; i++) { str = string.Empty...; } } } } 测试过程是分别将赋值语句str=""和str=string.Empty用两个函数执行10000次,所用时间如下所示: ? ...str == "" str.Equals("") str==string.Empty str.Equals(string.Empty) str .Length==0 测试程序如下: using...得出的结论:在字符串为空时,这五种判断语句的耗费时间由短到长 str .Length==0 str.Equals("") str==string.Empty str.Equals(string.Empty
ref string strErrorMessage) { bool flag = true; string applicationName = string.Empty...; string typeLibraryName = string.Empty; try { flag =..., ref typeLibraryName, InstallationFlags.CreateTargetApplication); strErrorMessage = string.Empty...ref string strErrorMessage) { bool flag = true; string applicationName = string.Empty...; string typeLibraryName = string.Empty; try { flag =
string.Empty : mObject["Category"].ToString(); //日志种类...string.Empty : mObject["EventCode"].ToString(); //日志...string.Empty : mObject["RecordNumber"].ToString();...string.Empty : getDateTimeFromDmtfDate(mObject["TimeWritten"].ToString())...string.Empty : mObject["SourceName"].ToString(); //
string.Empty : pd.Value.ToString().Trim()); Handler.LogHandler.Info(string.Format...string.Empty : pd.Value.ToString().Trim())); Handler.LogHandler.MemoryFatalException...string.Empty : pd.Value.ToString().Trim())); break;...string.Empty : pd.Value.ToString().Trim()); Handler.LogHandler.Info(string.Format...string.Empty : pd.Value.ToString().Trim())); break; }
AssemblyExecuteAdapterTransmitProperties config) { VirtualStream responseStream = null; string charset = string.Empty...assemblyexecute.ExecuteResponse(btsStream, inputparameters); #region saveresponsemessage string responsefilename = string.Empty...= string.Empty && config.SaveResponseMessagePath != "N") { if (!...VirtualStream(stream); } } catch(Exception e) { #region saveerrormessage string errorfilename = string.Empty...= string.Empty && config.SaveErrorMessagePath != "N") { if (!
; private string textField = string.Empty; private string groupField = string.Empty;...string formatter = string.Empty; private string loader = string.Empty; private string...loadFilter = string.Empty; private string onBeforeLoad = string.Empty; private string...onLoadSuccess = string.Empty; private string onLoadError = string.Empty; private string...onSelect = string.Empty; private string onUnselect = string.Empty; #endregion
> public static string Filter(string value) { if (string.IsNullOrEmpty(value)) return string.Empty...; value = Regex.Replace(value, @";", string.Empty); value = Regex.Replace(value, @"'", string.Empty...); value = Regex.Replace(value, @"&", string.Empty); value = Regex.Replace(value, @"%20", string.Empty...); value = Regex.Replace(value, @"--", string.Empty); value = Regex.Replace(value, @"==", string.Empty...); value = Regex.Replace(value, @"<", string.Empty); value = Regex.Replace(value, @">", string.Empty
/// public string GetCpuid() { var cpuid = string.Empty...GetDiskSerialNumber() { //这种模式在插入一个U盘后可能会有不同的结果,如插入我的手机时 var hDid = string.Empty.../// public string GetIpAddress() { var st = string.Empty...> /// public string GetCpuName() { var st = string.Empty...> /// public string GetBoardId() { var st = string.Empty
userName, password, null, false, "Base"); result = userManager.LogOnByOpenId(openId, string.Empty..., string.Empty); } // 登录时会自动记录进行日志记录,所以不需要进行重复日志记录 //...DC=CORP,DC=yourdomain,DC=com"; string domain = "corpwaiglobal"; string checkInput = string.Empty...; try { string statusCode = string.Empty; string statusMessage... = string.Empty; // 有什么权限的人才可以登录到系统 string permissionCode = string.Empty;
Users/liqi/Desktop/ad"; var files = Directory.GetFiles(path); string width = string.Empty...; //图片的高 string height = string.Empty;//图片的宽 string dir = string.Empty;
= String.Empty) { if (o is int) return (int...= String.Empty) { return o.ToString(); }...= String.Empty) { decimal Num = 0; decimal.TryParse...= String.Empty) { double Num = 0; double.TryParse...= String.Empty) { float Num = 0; float.TryParse
get { try { string str = string.Empty...str; } catch (Exception) { return string.Empty...get { try { string hdId = string.Empty...{ Tuple tuple = null; new Tuple(string.Empty..., string.Empty, string.Empty); ManagementObjectSearcher mos = new ManagementObjectSearcher
string.Empty); } //使用参数绑定过滤策略 public IActionResult Test([XssSchemeName("ebay")] RichText richText)...string.Empty); } 3.3 直接使用 1、使用内置的默认策略 //使用参数绑定过滤策略,这里需要添加模型绑定器 public IActionResult Test(RichText richText...string.Empty); } //这里不需要添加模型绑定器 public IActionResult Test(string source) { RichText richText=source...string.Empty); } 2、指定策略 public IActionResult Test(string source) { var policy = new AntisamyPolicy...string.Empty); }
2、String str2=String.Empty:同上。但是这是个静态方法,不会反复的重复申请内存,要优于1中的方式。...对于一个string类型的变量a,你会用哪种方式判断它为空,一般有以下三种: a == "" a == String.Empty a.length == 0 那么,你会用哪种方式判断...效率上 3 > 2 > 1,也就是a.length == 0 > a == String.Empty > a == ""。 ...那么,结论是,赋空字符串请用String.Empty(NULL不能输出,Empty可以输出),判断空字符串请用length。
= String.Empty) sb.Append(" WHERE ").Append(condition); sb.Append...= String.Empty) sb.Append(" WHERE ").Append(condition); sb.Append...= String.Empty) sb.Append(" AND ").Append(condition); sb.Append...= String.Empty) sb.Append(" WHERE ").Append(condition); sb.Append...= String.Empty) sb.Append(" WHERE ").Append(condition); sb.Append
string.Empty : objValue.ToString(); if (!...string.Empty : objValue.ToString(); if (!...string.Empty : objText.ToString(); _li.Value = objValue == null ?...string.Empty : objText.ToString(); chk.ToolTip = objText == null ?...string.Empty : objText.ToString(); _li.Value = objValue == null ?
GetAddress(); if (address == null) { ipAddress = string.Empty...Address.ToString(); } else { getway =string.Empty...ToString(); } else { dhcpServer = string.Empty...public string DnsMain { get { var dnsMain =string.Empty...public string DnsBackup { get { var dnsBackup = string.Empty
return -1; } using (StreamReader sr = new StreamReader(sqlFile)) { string line = string.Empty...semicolon = ";"; string sprit = "/", whiffletree = "-"; string sql = string.Empty...Log.WriteLog(sql + newLIne + ex.Message); } sql = string.Empty
领取专属 10元无门槛券
手把手带您无忧上云