6.4.5.3 一致的界面
文件拷貝、文件移動、 文件更名以及後邊的改變當前目錄在形式上都表現為從一個源文件到一個目標文件。因而可以采用統一的用戶界面，即ChangeForm對話框
這四個菜單項共用一個Click事件處理過程，通過對Sender參數的檢測，決定將要打開對話框的標題和顯示內容。當用戶按OK鍵關閉且目標文件(目錄)非空時，程序彈出一個消息對話框要求用戶進一步確認，而後執行相應的動作。
共用的事件處理過程FileChange的程序清單如下：
procedure TFMForm.FileChange(Sender: TObject);
var
ChangeForm: TChangeForm;
IsFile: Boolean;
begin
ChangeForm := TchangeForm.Create(Self);
IsFile := True;
with ChangeForm do
begin
if Sender = Move1 then Caption := 'Move'
else if Sender = Copy1 then Caption := 'Copy'
else if Sender = Rename1 then Caption := 'Rename'
else if Sender = ChangeDirectory1 then
begin
Caption:='Change Directory';
IsFile:=False;
end
else Exit;
if IsFile then
begin
CurrentDir.Caption := FileList.Directory;
ToFileName.Text := '';
end
else
begin
CurrentDir.Caption := DriveTabSet.Tabs[DriveTabSet.TabIndex];
ToFileName.Text := '';
end;
if (ShowModal <> idCancel) and (ToFileName.Text <> '') then
ConfirmChange(Caption, FromFileName.Text, ToFileName.Text);
end;
end;
其中用到的自定義私有過程ConfirmChange用於執行相應的動作：
procedure TFMForm.ConfirmChange(const ACaption, FromFile, ToFile: String);
begin
if MessageDlg(Format('%s %s to %s', [ACaption, FromFile, ToFile]),
mtConfirmation, [mbYes, mbNo], 0) = idYes then
begin
if ACaption = 'Move' then
MoveFile(FromFile, ToFile)
else if ACaption = 'Copy' then
CopyFile(FromFile, ToFile)
else if ACaption = 'Rename' then
RenameFile(FromFile, ToFile)
else if ACaption = 'Change Directory' then
changeDirectory(ToFile);
FileList.Update;
end;
end;
6.4.5.4 顯示文件屬性
當程序執行Properties 菜單項的Click 事件處理過程時，首先彈出一個TFileAttrForm類型的對話框，顯示文件的屬性
當用戶修改並確認後程序重新設置文件屬性。
Properties菜單項的Click事件處理過程如下：
procedure TFMForm.Properties1Click(Sender: TObject);
var
Attributes, NewAttributes: Word;
FileAttrForm: TFileAttrForm;
begin
FileAttrForm := TFileAttrForm.Create(self);
ShowFileAttr(FileAttrForm,FileList.FileName,FileList.Directory);
end;
其中過程ShowFileAttr的實現如下：
procedure TFMForm.ShowFileAttr(FileAttrForm:TFileAttrForm;
AFileName,Directory:String);
var
Attributes,NewAttributes: Word;
begin
with FileAttrForm do
begin
FileName.Caption := AFileName;
FilePath.Caption := Directory;
ChangeDate.Caption := DateTimeToStr(FileDateTime(AFileName));
Attributes := FileGetAttr(AFileName);
ReadOnly.Checked := (Attributes and faReadOnly) = faReadOnly;
Archive.Checked := (Attributes and faArchive) = faArchive;
System.Checked := (Attributes and faSysFile) = faSysFile;
Hidden.Checked := (Attributes and faHidden) = faHidden;
if ShowModal <> idCancel then
begin
NewAttributes := Attributes;
if ReadOnly.Checked then NewAttributes := NewAttributes or faReadOnly
else NewAttributes := NewAttributes and not faReadOnly;
if Archive.Checked then NewAttributes := NewAttributes or faArchive
else NewAttributes := NewAttributes and not faArchive;
if System.Checked then NewAttributes := NewAttributes or faSysFile
else NewAttributes := NewAttributes and not faSysFile;
if Hidden.Checked then NewAttributes := NewAttributes or faHidden
else NewAttributes := NewAttributes and not faHidden;
if NewAttributes <> Attributes then
FileSetAttr(AFileName, NewAttributes);
end;
end;
end;
以上過程中用到的函數FileDataTime在fmxutils單元中定義，返回一個TDatatime類型的變量。
function FileDateTime(const FileName: String): System.TDateTime;
begin
Result := FileDateToDateTime(FileAge(FileName));
end;
