Sixth chapter-Document management (ii) (3)

Design idea of 6.3.2 filename browsing and searching system

As an application instance of the file control, we developed a simple file name browsing lookup system. This system can be used to display the file name, to write the selected file to the list box, and to find the file by using the wildcard character entered in the File edit box.

Table 6.5 Design of parts

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Part property Features

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Filectrform position=podefault main Window

Dirlabel Display current directory

Fileedit taborder=0 Display current file/input file display match

FileListBox1 Fileedit=fileedit Display the current directory file

DirectoryListBox1 Dirlabel=dirlabel Display current drive directory

filelist= FileListBox1

DriveComboBox1 dirlist= DirectoryListBox1 Select the current drive

FilterComboBox1 filelist=filelistbox1 Select File Display Type

Filter= ' All Files (*.*) |*.*|

Source Files (*.pas) |*.pas|

Form Files (*.DFM) |*.dfm|

Project Files (*.DPR) |*.DPR '

LISTBOX1 Displays the selected or found files

Button1 caption= ' Find ' according to the contents of Fileedit

Button2 caption= ' exit ' exit system

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function and implementation of 6.3.3 file name browsing lookup system

6.3.3.1 displays the files in the current directory by the specified suffix name

Implementing this functionality requires only a proper connection between the controls, and no code support is required. The method of establishing a connection, as described in (6.3.1).

6.3.3.2 to add the selected file to the list box

In the FileListBox1 onclick event:

Procedure Tfilectrform.filelistbox1click (Sender:tobject);

Begin

If searched then

Begin

Searched: = False;

ListBox1.Items.Clear;

Label5.caption: = ' Selected Files ';

End

If NotInList (Extractfilename (filelistbox1.filename), listbox1.items) Then

LISTBOX1.ITEMS.ADD (Extractfilename (filelistbox1.filename));

End

Searched is a global variable that indicates whether the current display of ListBox1 is the result of a lookup or a file selected from FileListBox1.

function NotInList is used to determine whether the string to be added already exists in a Tstrings object. function returns a Boolean variable.

The specific implementation of NotInList is as follows.

Function tfilectrform.notinlist (filename:string;items:tstrings): Boolean;

Var

I:integer;

Begin

For I: = 0 to Items.count-1 do

If items[i] = FileName Then

Begin

NotInList: = False;

Exit;

End

NotInList: = True;

End

6.3.3.3 displays the files in the current directory by the specified matching string

When you enter a matching string in Fileedit and return, the File list box displays the matching result. This functionality is implemented in the Fileedit onkeypress event.

Procedure tfilectrform.fileeditkeypress (Sender:tobject; var key:char);

Begin

If Key = #13 Then

Begin

Filelistbox1.applyfilepath (Fileedit.text);

Key: = #0;

End

End

The Applyfilepath method provided by the File list box is the key to solving this problem.

6.3.3.4 finds files in the current directory by the specified matching string

In order to compare, we use another method to achieve the search function of the file, that is, using standard process FindFirst, FindNext. FileList1 is exactly the same as the content in ListBox1.

When the user clicks the Find button, the file that matches the string in Fileedit is displayed in ListBox1. Here is the implementation code.

Procedure Tfilectrform.button1click (Sender:tobject);

Var

I:integer;

Searchrec:tsearchrec;

Begin

Searched: = True;

Label5.caption: = ' Search result ';

ListBox1.Items.Clear;

FindFirst (FILEEDIT.TEXT,FAANYFILE,SEARCHREC);

LISTBOX1.ITEMS.ADD (Searchrec.name);

Repeat

I: = FindNext (SEARCHREC);

If i = 0 Then

LISTBOX1.ITEMS.ADD (Searchrec.name);

Until I <> 0;

End

Searchrec is a tsearchrec type of record. The definition of Tsearchrec is as follows:

Tsearchrec = Record

FILL:ARRAY[1..21] of Byte;

Attr:byte;

Time:longint;

Size:longint;

NAME:STRING[12];

End

A lot of information is provided in this structure, and flexible application will bring great convenience to programming. Let me give you a few examples here.

1. Detects the size of a given file.

function GetFileSize (const filename:string): Longint;

Var

Searchrec:tsearchrec;

Begin

If FindFirst (Expandfilename (FileName), faanyfile, Searchrec) = 0 Then

Result: = Searchrec.size

Else

Result: =-1;

End

This procedure will be applied in the next section.

2. Getting the timestamp of a given file is in fact equivalent to the Fileage function.

function Getfiletime (const filename:string): Longint;

Var

Searchrec:tsearchrec;

Begin

If FindFirst (Expandfilename (FileName), faanyfile, Searchrec) = 0 Then

Result: = Searchrec.time

Else

Result: =-1;

End

3. Detect the properties of the file. If the file has some attribute, the

Searchrec.attr and givenattr > 0

The values and meanings of the attribute constants correspond to the following table:

Table 6.6 Value and meaning of attribute constants

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Constant Value Description

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Fareadonly $01 read-only file

Fahidden $02 hidden files

Fasysfile $04 System files

Favolumeid $08 Volume label file

Fadirectory $ directory File

Faarchive $ file

Faanyfile $3f Any File

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