Reprint VB. NET programming call thunder download file (1)

During the crawling process, I did not know why and could not be caught directly, so I thought of calling thunder download. This was found on the website and I did not expect it to be very useful, I just used the simple file download function.

[Guide] This article describes in detail the process and steps of using VB. NET programming to call the file download function of Xunlei. The content includes: creating a referer call object, querying download task information using the Referer call object, and defining the functions of the thunder platform interface.

 

First, make sure that the computer has been installed with Xunlei. Open vs. NET and click the menu: Project> Add reference> COM> Add a reference to the thunderagent 1.0 Type Library.

1. Create a record call object

Private thundereng as new thunderagentlib. AGENT: Creates a record call object.

Thundereng. addtask ("", "save another file name", "Save directory", "task comment", "reference address", "Start mode", "Download from original address only ", "Number of threads downloaded from the original address") 'Add a download task

Thundereng. committasks () 'submit the download task

2. Use Xunlei to call objects to query download task information

Sfilesize = thundereng. gettaskinfo (txturl. Text, "filesize") 'to get the downloaded file size

Sdownedsize = thundereng. gettaskinfo (txturl. Text, "completedsize") 'to get the completed size

Sfilename = thundereng. gettaskinfo (txturl. Text, "FILENAME") 'get the file name

Ii. Definition of interfaces of the thunder Platform

Obtain information

1. BSTR getinfo (BSTR pinfoname)

Function: obtain information about thunder or platform.

Parameters:

Parameter Name	Description
Pinfoname	Information name, which has the following four types: ◆ "Thunderexists": Does thunder exist? ◆ "Thunderrunning": whether or not thunder runs ◆ "Thunderversion": the thunder version number ◆ "Platformversion": Platform version number

Return Value: The returned value is a string that corresponds to the pinfoname parameter.

Parameters	Return Value
"Thunderexists"	"True" exists, and "false" does not exist
"Thunderrunning"	"True" is running, and "false" is not running
"Thunderversion"	Thunder version "x. x"
"Platformversion"	Platform version "x. x"

2. hresult getinfostruct (INT pinfo)

Function: obtain all information related to thunder or platform.

Parameters:

Parameter Name

Description

Pinfo

It is actually a structure pointer of the thunder_info type. It is converted to the int type before calling. The platform information will be filled in the structure after calling, which is defined as follows: Typedef struct _ thunder_info { Bool bthunderexists; Bool bthunderrunning; Char szthunderversion [32]; Char szplatformversion [32]; } Thunder_info; After the function is called, the corresponding information is filled in the structure.

Return Value:

0	Obtained successfully
Non-0	Failed to get

Task operations

3. Add a task

Hresult addtask

(BSTR Purl,

BSTR pfilename = "",

BSTR ppath = "",

BSTR pcomments = "",

BSTR preferurl = "",

Int nstartmode =-1,

Int nonlyfromorigin = 0,

Int noriginthreadcount =-1 );

Function:

Add the download task information to the platform, which is not yet reflected in thunder.

Parameters:

Parameter Name	Description
Purl	Target URL, required Parameter
Pfilename	Another storage name. The default value is null, indicating that it is processed by thunder. Optional Parameter
Ppath	Storage directory. It is empty by default, indicating that it is processed by thunder. Optional Parameter
Pcomments	Download comments. The default value is null. Optional.
Preferurl	URL of the reference page. The default value is null. Optional.
Nstartmode	Start mode. The value 0 starts manually. The value 1 starts immediately. The default value is-1, indicating that it is processed by thunder. An optional parameter.
Nonlyfromorigin	Whether to download from the original URL, 1 from the original URL, more than 0 resources, 0 by default, optional parameter
Noriginthreadcount	Number of download threads from the original address. The value range is 1-10. The default value is-1, indicating that the thread is processed by thunder. Optional Parameter

 

 

4. Start the task

Hresult committaskss ()

Function:

Submit the information of the addtask download task to thunder for download and delete it from the platform.

Note: If the task added by addtask is not submitted and canceled (canceltasks is called), the agent object is blocked during analysis, therefore, the caller should not leave any unsubmitted or canceled tasks to prevent the script executor from stopping the response.

5. Cancel the task

Hresult canceltasks ()

Function:

Cancel all download task information added by addtask on the platform

6. Query Task Information

BSTR gettaskinfo (BSTR Purl, BSTR pinfoname );

Parameters:

Parameter Name	Description
Purl	Download URL Information to be queried
Pinfoname	Status name, which can be any of the following ◆ "Exists": whether purl is in the thunder task list ◆ "Path": storage directory ◆ "FILENAME": File Name ◆ "Filesize": File Size ◆ "Completedsize": downloaded size ◆ "Percent": download progress ◆ "Status": Task status

Return Value: The returned value is a string that corresponds to the pinfoname parameter.

Parameters	Return Value
"Exists"	"True" exists, "false" does not exist
"Path"	Storage directory, with backslash \, for example: C: \ tddownload \
"Filename"	File Name
"Filesize"	File size, in bytes, 0 indicates the size is unknown
"Completedsize"	Downloaded size, in bytes
"Percent"	Download progress, with 1 decimal point, for example: 70.0
"Status"	Task status, which has the following six statuses: . "Running": running status . "Stopped": stopped . "Failed": failure status . "Success": Successful . "Creatingfile": creating a data file . "Connecting": Connecting

7. gettaskinfostruct (INT ptaskinfo)

Function: Query all information of a task.

Parameter Name

Description

Ptaskinfo

It is actually a structure pointer of the thunder_taskinfo type. It is converted to the int type before calling. After calling, the structure will fill in the platform information, which is defined as follows: Typedef struct _ thunder_taskinfo { Char szurl [1024]; // task URL, prefilled Bool btaskexists; // whether the task exists. True indicates that the task exists. Char szpath [256]; // Local save path for download Char szfilename [256]; // local file name Ulonglong nfilesize; // File Size Ulonglong ncompletedsize; // completed size Char szpercent [16]; // percentage of completion, in the "56.8" Format Char szstatus [16]; // The Current Status, defining the same function as gettaskinfo } Thunder_taskinfo; The caller fills in the szurl member in the structure to specify the URL of the task to be queried. Then, after the function returns, the caller can obtain information about the task from other members.

In this example, allCode:

Imports system Imports system. Text Public class frmthunderclass frmthunder Private _ istartmode as integer 'thunder task download start Mode Private thundereng as new thunderagentlib. AGENT: Creates a record call object. Private sub frmthunder_load () sub frmthunder_load (byval sender as system. object, Byval e as system. eventargs) handles mybase. Load End sub Private sub btncancel_click () sub btncancel_click (byval sender as system. object, Byval e as system. eventargs) handles btncancel. Click Close () End sub 'Start the download task Private sub btnstartdown_click () sub btnstartdown_click (byval sender as system. object, Byval e as system. eventargs) handles btnstartdown. Click Dim ionlyfromorigin, ioriginthreadcount as integer Ionlyfromorigin = IIF (chkonlyfromorigin. Checked = true, 1, 0) Ioriginthreadcount = CINT (txtoriginthreadcounts. Text) If chkdefault. Checked then Ioriginthreadcount =-1 End if Thundereng. addtask (txturl. Text, txtsaveasfilename. Text, txtsavedir. Text, Txtcomment. Text, _ txtreferencepage. Text, _ istartmode, ionlyfromorigin, Ioriginthreadcount) Thundereng. committasks () Timer1.enabled = true End sub Private sub radmaual_click () sub radmaual_click (byval sender as system. object, Byval e as system. eventargs) handles radmaual. Click, radimmediate. Click, raddefault. click dim rad as radiobutton = ctype (sender, radiobutton) _ istartmode = CINT (rad. tag) end sub 'query task download information regularly when the task starts. private sub timer1_tick () sub timereffectick (byval sender as system. object, byval e as system. eventargs) handles timer1.tick dim sfilesize, sdownedsize, sStatus, sfilename, spercent as string try sStatus = thundereng. gettaskinfo (txturl. text, "status") sfilesize = thundereng. gettaskinfo (txturl. text, "filesize") sdownedsize = thundereng. gettaskinfo (txturl. text, "completedsize") sfilename = thundereng. gettaskinfo (txturl. text, "FILENAME") lbldownedsize. TEXT = string. format (lbldownedsize. tag, sdownedsize) lblfilesize. TEXT = string. format (lblfilesize. tag, sfilesize) lbltaskstatus. TEXT = string. format (lbltaskstatus. tag, sStatus) lblfilename. TEXT = string. format (lblfilename. tag, sfilename) spercent = thundereng. gettaskinfo (txturl. text, "percent") 'Get the download percentage lblprogress. TEXT = string. format (lblprogress. tag, Spercent. Remove (3, Len (spercent)-3 )) Catch ex as exception End try End sub Private sub chkonlyfromorigin_checkedchanged_1 () sub Chkonlyfromorigin_checkedchanged_1 (byval sender as system. object, Byval e as system. eventargs) handles chkonlyfromorigin. checkedchanged Panel1.enabled = chkonlyfromorigin. Checked End sub Private sub groupboxincluenter () sub groupboxincluenter (byval sender as system. object, Byval e as system. eventargs) handles groupbox1.enter End sub End Class