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unit MainUnit;
interface
uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, Registry;
type TfrmMain = class(TForm) btn1: TButton; edt1: TEdit; lbl1: TLabel; procedure btn1Click(Sender: TObject); private { Private declarations } public { Public declarations } end;
var frmMain: TfrmMain;
function ExpandEnvironment(const strValue: string): string; function SetGlobalEnvironment(const envName, envValue: string; const isUser: Boolean = True): Boolean;
implementation
{$R *.dfm}
procedure TfrmMain.btn1Click(Sender: TObject);var path:string;begin SetGlobalEnvironment('JAVA_HOME',edt1.Text); SetGlobalEnvironment('CLASSPATH','.;%JAVA_HOME%/jre/lib/rt.jar;%JAVA_HOME%/lib/tools.jar;%JAVA_HOME%/lib;'); path := ExpandEnvironment('%PATH%'); path := path + ';%JAVA_HOME%/bin'; SetGlobalEnvironment('PATH',path);end;
/// <summary>/// 设置系统级环境变量参数函数/// </summary>/// <param name="envName">环境变量名</param>/// <param name="envValue">环境变量值</param>/// <param name="isUser">为true表示只更新当前操作员的环境变量</param>/// <returns></returns>function SetGlobalEnvironment(const envName, envValue: string; const isUser: Boolean = True): Boolean;resourcestring REG_MLOCATION ='System/CurrentControlSet/Control/Session Manager/Environment'; // 环境变量存储在注册表中的位置 REG_ULOCATION = 'Environment';begin with TRegistry.Create do try if isUser then // 设置当前用户的环境变量 Result := OpenKey(REG_ULOCATION, True) else // 设置系统环境变量,对所有用户有效 begin RootKey := HKEY_LOCAL_MACHINE; Result := OpenKey(REG_MLOCATION, True); end;
if Result then begin WriteString(envName, envValue); // 设置注册表中环境变量的值
SetEnvironmentVariable(PChar(envName), PChar(envValue)); // 更新当前进程的环境变量值
SendMessage(HWND_BROADCAST, WM_SETTINGCHANGE, 0, Integer(PChar('Environment'))); // 发送消息通知所有上层的窗口,环境参数发生变化 end; finally Free; end;end;
/// <summary>/// 获取环境变量/// </summary>/// <param name="strValue">环境变量名</param>/// <returns>环境变量值</returns>function ExpandEnvironment(const strValue: string): string;var chrResult: array[0..1023] of Char; wrdReturn: DWORD;begin wrdReturn := ExpandEnvironmentStrings(PChar(strValue), chrResult, 1024); if wrdReturn = 0 then Result := strValue else begin Result := Trim(chrResult); end;end;
end.
来源:https://www.cnblogs.com/toosuo/p/3698587.html
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