Delphi 如何清空Image1
Image1.Picture := nil;
Image1.Picture := nil;
方案1:您会非常失望,因为根据文件放入目录结构的顺序,文件的删除会导致FindNext跳过匹配的现有文件,因此您最终将不会删除所有想要的文件。您要做的是设置要删除的列表。然后,一旦设置了列表,便可以将其删除。注意:请注意,许多人认为您要做的就是建立列表然后删除它们。这不是真的。有许多文件可以设置只读/只读属性等。因此,您必须先清除此文件,否则删除将失败。因此,如果您在我的例程中注意到,我会清除可能已为文件设置的所有属性。这是一个例子:procedure DeleteTempRAW(S1: String)
Answer 1procedure TForm1.Button1Click(Sender: TObject);var Stream1, Stream2: TFileStream;begin Stream1 := TFileStream.Create('c:\file4', fmCreate or fmShareExclusive); try { first file } Stream2 := TFileStream.Create('c:\file1',
Test for a binary form file//判断二进制格式文件function IsDFMBinary(FileName: string): Boolean;var F: TFileStream; B: Byte;begin B := 0; F := TFileStream.Create(FileName, fmOpenRead); try F.Read( B, 1 ); Result := B = $FF; finally F.Free; end;end;
function BlockInput(fBlockInput: Boolean): DWORD; stdcall;external 'user32.dll';//delphitop.com//点击按钮,系统会禁止一切输入操作,5秒后解除锁定。procedure TForm2.Button1Click(Sender: TObject);begin BlockInput(True); Label1.Caption := 'Blocked'; Application.P
function GetEnvVariable(Name: string; User: Boolean = True): string;var Str: array[0..255] of char;begin with TRegistry.Create do try if User then begin RootKey := HKEY_CURRENT_USER; //OpenKey('Environment', False); OpenKe
procedure SetEditNumeric(Handle: THandle);begin SetWindowLong(Handle, GWL_STYLE, GetWindowLong(Handle, GWL_STYLE) or ES_NUMBER);end;//点击按钮后,edit1 只能输入数字procedure TForm2.Button1Click(Sender: TObject);beginSetEditNumeric(edit1.Handle);end;
function ExecAndWait(sExe, sCommandLine: string): Boolean;var dwExitCode: DWORD; tpiProcess: TProcessInformation; tsiStartup: TStartupInfo;begin Result := False; FillChar(tsiStartup, SizeOf(TStartupInfo), 0); tsiStartup.cb := SizeOf(TStartupInfo);