如何调用API函数？

该程序演示了如何用鼠标来获得任何像素的RGB颜色。该程序使用了计时器，间尘嫌隔设置为0.01秒来捕捉事件，使用了GetPixel

,

GetCursorPos

和GetDC

WinAPI调用，来获得屏幕上任何地方的像素的御扮颜色。

option

Explicit

'在表单镇兄灶中加入计时器，使用鼠标移动到屏幕上任何一处，RGB颜色就会显示在表单中的Caption中

'

private

Type

POINTAPI

x

as

Long

y

as

Long

End

Type

'

private

Declare

Function

GetPixel

Lib

"gdi32"

(byval

hdc

as

Long,

_

byval

x

as

Long,

byval

y

as

Long)

as

Long

private

Declare

Function

GetCursorPos

Lib

"user32"

(lpPoint

as

POINTAPI)

as

Long

private

Declare

Function

GetWindowDC

Lib

"user32"

(byval

hwnd

as

Long)

as

Long

'

private

Sub

Form_Load()

Timer1.Interval

=

100

End

Sub

'

private

Sub

Timer1_Timer()

Dim

tPOS

as

POINTAPI

Dim

sTmp

as

string

Dim

lColor

as

Long

Dim

lDC

as

Long

'

lDC

=

GetWindowDC(0)

Call

GetCursorPos(tPOS)

lColor

=

GetPixel(lDC,

tPOS.x,

tPOS.y)

Label2.BackColor

=

lColor

'

sTmp

=

Right$("000000"

&

Hex(lColor),

6)

Caption

=

"R:"

&

Right$(sTmp,

2)

&

"

G:"

&

mid$(sTmp,

3,

2)

&

"

B:"

&

Left$(sTmp,

2)

End

Sub

至于获取当前窗口,可以使用

Public

Declare

Function

GetForegroundWindow

Lib

"user32"

()

As

Long

获取当前活动窗体的句柄,再使用GetWindowText的API能获取到相应的标题啦!

Public

Declare

Function

GetForegroundWindow

Lib

"user32"

()

As

Long

Public

Declare

Function

SendMessage

Lib

"user32"

Alias

"SendMessageA"

(ByVal

hwnd

As

Long,

ByVal

wMsg

As

Long,

ByVal

wParam

As

Long,

lParam

As

Any)

As

Long

Public

Const

WM_GETTEXT

=

&HD

Public

Function

GetWin()

As

String

Dim

tmp

As

Long

Dim

iLen

As

Long

Dim

Txt

As

String

tmp

=

GetForegroundWindow

Txt

=

String(255,

Chr(0))

iLen

=

SendMessage(tmp,

WM_GETTEXT,

Len(Txt),

ByVal

Txt)

Txt

=

Left(Txt,

iLen)

GetWin=Txt

End

Function

以上代码是获取当前窗体的标题代码!(这里没使用GetWindowText的API)

程序依靠调用外部shutdown实现关机。本例中定时100秒。槐判枯

将冲春100改为0，实现立铅洞即关机。

方法一：

#include

#include

void

main(void)

{

system("shutdown.exe

-s

-t

100")

getch()

system("shutdown.exe

-a")

}

方法二：

打开txt文档，输入

shutdown

-s

-t

100

保存。将文件扩展名保存为.bat。

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