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Example topics / PreviewFiles method and PreviewingFiles event example for Delphi
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    PreviewFiles method and PreviewingFiles event example for Delphi
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     The first function of the following code previews all the files that match the "C:\DATA\*.dat" wildcard and that are bigger than 65536 bytes. Keep in mind that any subdirectories in C:\DATA will also be searched for *.dat files, because the ProcessSubfolders property is set to True by default, even if the code below doesn't explicitly set it. The second function below is a handler written for the PreviewingFile event that displays each file previewed, along with some other of the file's information, in a listbox. The third function below is a handler written for the ProcessCompleted event, that adds summary information into the same listbox. The code assumes you have placed a button, a listbox and an Xceed Zip control on a form, and named them Button1, ListBox1 and XceedZip1 respectively.

    We start with the handler for the button's click event. The code will start the previewing.

    Delphi Copy Code

    procedure Tform1.Button1Click(Sender: Tobject);

    var   ResultCode : integer;  

       begin
          XceedZip1.License( 'your license key' ); 

          XceedZip1.FilesToProcess := 'c:\data\*.dat'; 
          XceedZip1.MinSizeToProcess := 65536
          { Added this as an example of what you can do with the PreviewFiles method }  

          { We don't need to set the ZipFilename property, because PreviewFiles doesn't look at what's in the Zip file already. }  

          { Now call the PreviewFiles method without the optional parameter } 
          ResultCode = XceedZip1.PreviewFiles  

          { If we wanted to know the total compressed size of all the previewed files, we could have used this line instead: } 

          { ResultCode = XceedZip1.PreviewFiles(True); } 

          { If you do this, the ProcessCompleted event's lBytesOutput parameter will contain the total compressed size. }  

          { Now we check the return value } 
          If ResultCode <> xerSuccess Then 
             ShowMessage('Unsuccessful. Error #'+IntToStr(ResultCode))
          Else 
             ShowMessage('Operation successful.'); 
       end;
    end;

    Here's the handler for the PreviewingFile event. It will add each previewed file's name and info to the listbox.

    Delphi Copy Code

    procedure TFOrm1.XceedZip1PreviewingFile(Sender: Tobject; const sFilename, sSourceFilename: WideString; lSize: Integer; xAttributes: ToleEnum; dtLastModified, dtLastAccessed, dtCreated: TdateTime; bExcluded: WordBool; xReason: ToleEnum);

    begin
       ListBox1.Items.Add('Filename : ' + sFilename); 
       ListBox1.Items.Add('Date : ' + dtCreated); 
       ListBox1.Items.Add('Size : ' + lSize); 
    end;

    Here's the handler for the ProcessCompleted event. It adds summary information to the listbox.

    Delphi Copy Code

    procedure TFOrm1.XceedZip1ProcessCompleted(Sender: Tobject; lFilesTotal, lFilesProcessed, lFilesSkipped, lBytesTotal, lBytesProcessed, lBytesSkipped, lBytesOutput: Integer; nCompressionRatio: SmallInt; xResult: ToleEnum);

    begin

       ListBox1.Items.Add('=====================================" 
       ListBox1.Items.Add('Summary : '); 
       ListBox1.Items.Add(''); 
       ListBox1.Items.Add('Total number of Files :' + lFilesTotal); 

       ListBox1.Items.Add('Total compressed Size : ' + lBytesOutput); { This information is only valid if you called the PreviewFiles method with the optional parameter set to True } 

    end;

     

     

     

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