from here?https://blog.csdn.net/weixin_3210910...ails/117191984
This may be the original link that I can't open to view.
http://vbcity.com/forums/t/73200.aspx
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This may be the original link that I can't open to view.
http://vbcity.com/forums/t/73200.aspx
Code:
Dim r As RECT
r.Left = 10
r.Top = 10
r.Right = 300
r.Bottom = 550
Call gdiDrawGradient(Me.hdc, r, vbRed, vbBlue, True)Code:
Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Declare Function timeGetTime Lib "winmm.dll" () As Long
Declare Function timeBeginPeriod Lib "winmm.dll" (ByVal uPeriod As Long) As Long
Declare Function timeEndPeriod Lib "winmm.dll" (ByVal uPeriod As Long) As Long
Public PauseTime As Long
Public Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
Private Declare Function CreateSolidBrush Lib "gdi32" (ByVal crColor As Long) As Long
Private Declare Function FillRect Lib "user32" (ByVal hdc As Long, lpRect As RECT, ByVal hBrush As Long) As Long
Public Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Function Pause(HowLong As Long)
Dim tick As Long
tick = timeGetTime()
Do
DoEvents
Sleep 1
Loop Until tick + HowLong < timeGetTime
End Function
Public Sub gdiDrawGradient( _
ByVal hdc As Long, _
ByRef rct As RECT, _
ByVal lEndColor As Long, _
ByVal lStartColor As Long, _
ByVal bVertical As Boolean)
Dim lStep As Long
Dim lPos As Long, lSize As Long
Dim bRGB(1 To 3) As Integer
Dim bRGBStart(1 To 3) As Integer
Dim dR(1 To 3) As Double
Dim dPos As Double, d As Double
Dim hBr As Long
Dim tR As RECT
LSet tR = rct
If bVertical Then
lSize = (tR.Bottom - tR.Top)
Else
lSize = (tR.Right - tR.Left)
End If
lStep = lSize \ 255
If (lStep < 3) Then
lStep = 3
End If
bRGB(1) = lStartColor And &HFF&
bRGB(2) = (lStartColor And &HFF00&) \ &H100&
bRGB(3) = (lStartColor And &HFF0000) \ &H10000
bRGBStart(1) = bRGB(1): bRGBStart(2) = bRGB(2): bRGBStart(3) = bRGB(3)
dR(1) = (lEndColor And &HFF&) - bRGB(1)
dR(2) = ((lEndColor And &HFF00&) \ &H100&) - bRGB(2)
dR(3) = ((lEndColor And &HFF0000) \ &H10000) - bRGB(3)
For lPos = lSize To 0 Step -lStep '
' Draw bar
If bVertical Then
tR.Top = tR.Bottom - lStep
Else
tR.Left = tR.Right - lStep
End If
If tR.Top < rct.Top Then
tR.Top = rct.Top
End If
If tR.Left < rct.Left Then
tR.Left = rct.Left
End If
hBr = CreateSolidBrush((bRGB(3) * &H10000 + bRGB(2) * &H100& + bRGB(1)))
FillRect hdc, tR, hBr
DeleteObject hBr
' Adjust colour '
dPos = ((lSize - lPos) / lSize)
If bVertical Then
tR.Bottom = tR.Top
bRGB(1) = bRGBStart(1) + dR(1) * dPos
bRGB(2) = bRGBStart(2) + dR(2) * dPos
bRGB(3) = bRGBStart(3) + dR(3) * dPos
Else
tR.Right = tR.Left
bRGB(1) = bRGBStart(1) + dR(1) * dPos
bRGB(2) = bRGBStart(2) + dR(2) * dPos
bRGB(3) = bRGBStart(3) + dR(3) * dPos
End If
If PauseTime > 0 Then Pause PauseTime
Next lPos
End Sub