如何使用Delphi从文件扩展名获取图标和描述？

Question

基本上我有一个TcxGrid,它将列出各种文件名,我想根据文件扩展名给出更多细节,特别是它的描述(例如.PDF它的"Adobe Acrobat文档")和它的相关图标.

我注意到有一个非常类似的问题,但它与C#有关,我想要一些基于Delphi的东西.

关于在哪里查找这种信息的建议是好的,如果有一个类似于上面的C#帖子中提到的类(显然在Delphi中),这将是很好的.

Answer 1

感谢Rob Kennedy将我指向了ShGetFileInfo的方向.然后我用Google搜索并找到了这两个例子 - Delphi 3000,Torry's.从那以后我写了下面的课来做我需要的.

而且,就在我完成比尔米勒的回答时,我给了我最后一点帮助.最初我将完整的文件名传递给ShGetFileInfo,这不是我想要的理想选择.传递"*.EXT"的调整很好.

班级可以做更多的工作,但它做我需要的.它似乎处理没有相关细节的文件扩展名.

最后,在我使用的内容中,我将其切换为使用TcxImageList而不是TImageList,因为我在图标上出现黑色边框时出现问题,因为它是一个快速修复.

unit FileAssociationDetails;

{
  Created       : 2009-05-07
  Description   : Class to get file type description and icons.
                  * Extensions and Descriptions are held in a TStringLists.
                  * Icons are stored in a TImageList.

                  Assumption is all lists are in same order.
}

interface

uses Classes, Controls;

type
  TFileAssociationDetails = class(TObject)
  private
    FImages : TImageList;
    FExtensions : TStringList;
    FDescriptions : TStringList;
  public
    constructor Create;
    destructor Destroy; override;

    procedure AddFile(FileName : string);
    procedure AddExtension(Extension : string);    
    procedure Clear;    
    procedure GetFileIconsAndDescriptions;

    property Images : TImageList read FImages;
    property Extensions : TStringList read FExtensions;
    property Descriptions : TStringList read FDescriptions;
  end;

implementation

uses SysUtils, ShellAPI, Graphics, Windows;

{ TFileAssociationDetails }

constructor TFileAssociationDetails.Create;
begin
  try
    inherited;

    FExtensions := TStringList.Create;
    FExtensions.Sorted := true;
    FDescriptions := TStringList.Create;
    FImages := TImageList.Create(nil);
  except
  end;
end;

destructor TFileAssociationDetails.Destroy;
begin
  try
    FExtensions.Free;
    FDescriptions.Free;
    FImages.Free;
  finally
    inherited;
  end;
end;

procedure TFileAssociationDetails.AddFile(FileName: string);
begin
  AddExtension(ExtractFileExt(FileName));
end;

procedure TFileAssociationDetails.AddExtension(Extension : string);
begin
  Extension := UpperCase(Extension);
  if (Trim(Extension) <> '') and
     (FExtensions.IndexOf(Extension) = -1) then
    FExtensions.Add(Extension);
end;

procedure TFileAssociationDetails.Clear;
begin
  FExtensions.Clear;
end;

procedure TFileAssociationDetails.GetFileIconsAndDescriptions;
var
  Icon: TIcon;
  iCount : integer;
  Extension : string;
  FileInfo : SHFILEINFO; 
begin
  FImages.Clear;
  FDescriptions.Clear;

  Icon := TIcon.Create;
  try
    // Loop through all stored extensions and retrieve relevant info
    for iCount := 0 to FExtensions.Count - 1 do
    begin
      Extension := '*' + FExtensions.Strings[iCount];

      // Get description type
      SHGetFileInfo(PChar(Extension),
                    FILE_ATTRIBUTE_NORMAL,
                    FileInfo,
                    SizeOf(FileInfo),
                    SHGFI_TYPENAME or SHGFI_USEFILEATTRIBUTES
                    );
      FDescriptions.Add(FileInfo.szTypeName);

      // Get icon and copy into ImageList
      SHGetFileInfo(PChar(Extension),
                    FILE_ATTRIBUTE_NORMAL,
                    FileInfo,
                    SizeOf(FileInfo),
                    SHGFI_ICON or SHGFI_SMALLICON or
                    SHGFI_SYSICONINDEX or SHGFI_USEFILEATTRIBUTES
                    );
      Icon.Handle := FileInfo.hIcon;
      FImages.AddIcon(Icon);
    end;
  finally
    Icon.Free;
  end;
end;

end.

这里还有一个使用它的示例测试应用程序,它非常简单,只是一个带有TPageControl的表单.我实际使用的不是这个,而是使用TcxGrid中的Developer Express TcxImageComboxBox.

unit Main;

{
  Created       : 2009-05-07
  Description   : Test app for TFileAssociationDetails.
}

interface

uses
  Windows, Forms, FileAssociationDetails, Classes, Controls, ComCtrls;

type
  TfmTest = class(TForm)
    PageControl1: TPageControl;
    procedure FormShow(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
    FFileDetails : TFileAssociationDetails;
  public
    { Public declarations }
  end;

var
  fmTest: TfmTest;

implementation

{$R *.dfm}

procedure TfmTest.FormShow(Sender: TObject);
var
  iCount : integer;
  NewTab : TTabSheet;
begin
  FFileDetails := TFileAssociationDetails.Create;
  FFileDetails.AddFile('C:\Documents and Settings\...\Test.XLS');
  FFileDetails.AddExtension('.zip');
  FFileDetails.AddExtension('.pdf');
  FFileDetails.AddExtension('.pas');
  FFileDetails.AddExtension('.XML');
  FFileDetails.AddExtension('.poo');

  FFileDetails.GetFileIconsAndDescriptions;
  PageControl1.Images := FFileDetails.Images;

  for iCount := 0 to FFileDetails.Descriptions.Count - 1 do
  begin
    NewTab := TTabSheet.Create(PageControl1);
    NewTab.PageControl := PageControl1;
    NewTab.Caption := FFileDetails.Descriptions.Strings[iCount];
    NewTab.ImageIndex := iCount;
  end;
end;

procedure TfmTest.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  PageControl1.Images := nil;
  FFileDetails.Free;
end;

end.

谢谢大家的回答!