China DOS Union

I happened to come across the Vbs tutorial posted by the moderator bjsh when I was browsing around today. It's really quite good: http://www.cn-dos.net/forum/viewthread.php?tid=30588. I might occasionally excerpt some things from it in the future.

1. Because the third parameter of Msgbox is the title, you can save some effort like the following:

MsgBox "1",,"2"

2. Whenever you assign an object reference to a variable, you need to use the Set keyword. Then what is an object reference? Any variable other than strings, numeric values, and Boolean values is an object reference.

3. Run stops when encountering spaces during runtime resolution. The solution is to use double quotes. For example: wscript.shell.run"""D:\Study\VBS\windows 脚本编程核心技术精解"""。
The run function has three parameters. The first parameter is the path of the program you want to execute. The second parameter is the form of the window. 0 is running in the background; 1 means running normally; 2 means activating the program and displaying it as minimized; 3 means activating the program and displaying it as maximized... The third parameter indicates whether this script waits or continues to execute. If set to true, the script will wait until the called program exits before continuing to execute.

1.On Error Resume Next
This line of code can tell VBS to skip the statement where an error occurs during runtime and immediately execute the statement that follows it.

2. Although the On Error Resume Next statement can prevent the VBS script from stopping when an error occurs, it cannot truly handle the error. To handle the error, you need to add some statements in the script to check the error condition and handle it when an error occurs.

VBScript provides an object, the err object, which has two methods: clear and raise, and five properties: description, helpcontext, helpfile, number, and source. The err object can be used directly without referencing an instance.

About operating the registry, I would like to say:

　　1. Obviously, we need to rely on (reference) Wscript.Shell.

　　2. The end of the path is with the "\" ending, for example, "HKCU\....\Thing\" means this is a key; if there is no "\", such as "HKCU\....\Thing", then it means this is a value (value and data are not the same concept)

　　3. For write operations, you can freely extend after a key in (on the path), without worrying about whether the key or value itself exists; if it does not exist, then it is "added all the way", and if it exists, then it is modified. All Right?!

　　4. If you want to delete a value, then Wscript.Shell.Regdelete "HKCU\....\Thing";
　　If you want to clear the data of that value, then Wscript.Shell.Regwrite "HKCU\....\Thing", "".

[ Last edited by Billunique on 2007-6-14 at 04:35 PM ]

Try using the following code in the VB editor to roughly understand some things about file operations:

Set fs = CreateObject("scripting.filesystemobject")

'Set ff = fs.GetFile("d:\bak\11.txt")

'MsgBox ff

'i = ff.Attributes

'MsgBox i

Set fo = fs.OpenTextFile("d:\bak\11.txt")

'MsgBox fo

v = fo.Read(5)

MsgBox v

line1 = fo.ReadLine

line2 = fo.ReadLine

MsgBox line2

con = fo.ReadAll

MsgBox con



'The content of the 11.txt file can be like this:

cndos.1111 aaa

22222

What is to be explained is that the Read operation after OpenTextFile seems to be "cutting" the text; the above read first, and then only can read the part after "cutting" plus the part within its "capability range" (I can't explain it clearly, heh heh). The capability range of ReadLine is only to read one line, and cannot read a specified line.

The usage of Write and WriteLine is similar, but when opening, it needs "OpenTextFile(~.txt, 2, ", where 1 means read-only, 2 means write, 8 means append; true means create if it doesn't exist, and the default is false.

If you want to both write and read, then you must set the mode (that is, 1, 2, 8) first before performing specific operations. One operation corresponds to one mode, otherwise the script will report an error.

[ Last edited by Billunique on 2007-6-15 at 07:50 PM ]

Using Arrays


　　Variable arrays are just groups of variables that can be accessed using an index number. This is especially useful if your script needs to look up information stored in variables.

　　Variable arrays always need to be declared so that VBScript knows how much storage space it should reserve. You can declare variable arrays using Dim or ReDim.

　　Dim initializes a variable array of fixed size. You need to specify the number of elements the array should hold, and you cannot expand or shrink the array afterwards.

　　Using Dim, you need to specify the number of entries as a constant or absolute number. You are not allowed to use a variable to feed the size of Dim. ReDim will also accept variables.

　　It generally says that ReDim is better than Dim because it can change the size of the array at any time, so let's just use ReDim. Here's a simple example:

Dim myarray(5)



myarray(0)="Unknown"

myarray(1)="Removable"

myarray(2)="Fixed"

myarray(3)="Remote"

myarray(4)="CD-ROM"

myarray(5)="RAM-Drive"



'find out the type of drives



Set fs = CreateObject("scripting.filesystemobject")



'get all drives:

Set drives = fs.Drives



' The Drives property: returns a Drives collection containing all available Drive objects on the local machine



For Each drive In drives

	letter = drive.DriveLetter

	kind = myarray(drive.DriveType)

	list = list & "Drive " & letter & " is of type " & kind & vbCr

Next



' The DriveLetter property: returns the drive letter

' The DriveType property: returns a number indicating the drive type, in fact, the system's definition is consistent with the definition above in this example.



MsgBox list

[ Last edited by Billunique on 2007-6-18 at 11:56 AM ]

### Split and Join

Actually, Split can simplify the above code.

MyArray="unknown;Removable;Fixed;Remote;CD-ROM;RAM-Drive"

MyArray=Split(MyArray,";")

.......

Split is actually using a delimiter to turn a string into an array.

And Join is to turn each element in the array into a string. For example:

Myarray(0)="This "

Myarray(1)="is "

Myarray(2)="Billunique"

MyString=Join(Myarray)



'Then MyString="This is Billunique"

I haven't been here for three months. I'm really ashamed. I've been lost again...

Haha, your second post has inspired me. Thanks

Come and say hello, one of my favorite forums!! Long time no see~

Want to learn from the building owner. When I have time after going to college, I will also come here to write study notes.

Gua gua, show your face, blow a bubble

Let me take a look