API窗口函数delphi.docVIP

WinAPI: GetDesktopWindow - 返回桌面窗口的句柄 //声明: GetDesktopWindow: HWND; {无参数; 返回桌面窗口的句柄} //举例: var h: HWND; begin h := GetDesktopWindow; ShowMessage(IntToStr(h)); end; WinAPI: SetWindowText - 设置窗口标题 //声明: SetWindowText( hWnd: HWND; {窗口句柄} lpString: PChar {新标题串指针} ): BOOL; //举例: var s: string; begin s := 新标题; SetWindowText(Handle, PAnsiChar(s)); end; WinAPI: GetWindowText - 获取窗口标题 //声明: GetWindowText( hWnd: HWND; {窗口句柄} lpString: PChar; {接收文本的缓冲区的指针} nMaxCount: Integer {指定缓冲区大小, 其中包含NULL字符; 如果文本超出，会被被截断} ): Integer; {返回字符个数, 不包括中断的空字符; 如果标题为空或句柄无效, 则返回零} //举例: var arr: array[0..254] of Char; begin GetWindowText(Handle, @arr, SizeOf(arr)); ShowMessage(arr); {Form1} end; //标题文本个数: var arr: array[0..254] of Char; num: Integer; begin num := GetWindowText(Handle, arr, SizeOf(arr)); ShowMessage(IntToStr(num)); {5} end; WinAPI: GetWindowTextLength - 获取窗口标题长度 //声明: GetWindowTextLength( hWnd: HWND {窗口句柄} ): Integer; {返回窗口标题长度} //举例: var i: Integer; begin i := GetWindowTextLength(Self.Handle); ShowMessage(IntToStr(i)); end; WinAPI: GetForegroundWindow - 获取前台窗口的句柄 //声明: GetForegroundWindow: HWND; //举例: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls; type TForm1 = class(TForm) {先添加如下三个控件} Button1: TButton; Memo1: TMemo; Timer1: TTimer; procedure Timer1Timer(Sender: TObject); procedure Button1Click(Sender: TObject); procedure FormCreate(Sender: TObject); end; var Form1: TForm1; implementation {$R *.dfm} var h: HWND; {把句柄定义成全局变量以避免重复} {准备工作} procedure TForm1.FormCreate(Sender: TObject); begin Memo1.Align := alLeft; Memo1.ScrollBars := ssBoth; Timer1.Enabled := False; Timer1.Interval := 100; end; {启动与停止} procedure TForm1.Button1Click(Sender: TObject); begin Timer1.Enabled := not Timer1.Enabled; case Timer1.Enabled of True : Text := 开始截获; False: Text := 停止截获; end; Memo1.C