如何画圆，使圆内的颜色为渐变色

[zx095x]

我是这样画圆的。只能填充一种颜色，希望填充渐变色：

    Picture1.FillStyle = 0
    Picture1.FillColor = RGB(160, 130, 0) '外圈填充色

    Picture1.DrawWidth = 1
    Picture1.Circle (BaseX, BaseY), printR2 * 1.3, RGB(143, 122, 16) '画外圈圆

[游子]

顶楼上。。。。。。。。。。

[zx095x]

谢谢这位朋友，俺想要的是从上到下渐变，不是这种同心渐变

[Quote=引用 2 楼 hnuqinhuan 的回复:]
路过 顶
[/Quote]

[bcrun]

楼主你没仔细看他的代码,他那个圆圈好像也是用的线性渐变,是多个三角形拼起来的.

当然,你如只需要直接从上到下渐变的,参考他这个代码就行了,注意,我在后面补充的参数(默认值是水平方向的)GRADIENT_FILL_RECT_V

Private Sub Command2_Click()
    DrawGradientRect Me.hDC, 10, 10, 200, 100, vbBlue, vbGreen, GRADIENT_FILL_RECT_V
    Me.Refresh
End Sub

[贝隆]

填充的思想就是将圆细微划分成很多部分，每个部分填充不同的颜色，颜色之间是渐渐变化的。

[zx095x]

我不会改啊

[Quote=引用 6 楼 bcrun 的回复:]
楼主你没仔细看他的代码,他那个圆圈好像也是用的线性渐变,是多个三角形拼起来的.

当然,你如只需要直接从上到下渐变的,参考他这个代码就行了,注意,我在后面补充的参数(默认值是水平方向的)GRADIENT_FILL_RECT_V


VB code
Private Sub Command2_Click()
DrawGradientRect Me.hDC, 10, 10, 200……
[/Quote]

[贝隆]

Private Sub Command1_Click()
    Dim bytR As Byte
    Dim bytG As Byte
    Dim bytB As Byte
    Dim hBrush As Long
    Dim OldMode As Integer
    Dim RetVal As Integer
    Dim StepSize As Integer
    Dim X As Integer
    Dim FillArea As RECT
    
    Dim BaseX As Long
    Dim BaseY As Long
    Dim R2 As Long
    Dim lngP As Long
    
    Picture1.AutoRedraw = True
    R2 = 1000
    BaseX = 0.5 * Picture1.Width
    BaseY = 0.5 * Picture1.Height
    Picture1.DrawWidth = 1
    For X = 255 To 1 Step -1
        Picture1.Circle (BaseX, BaseY), (R2 / 255) * X, RGB(X, 0, 0)
    Next X
    Picture1.Refresh
End Sub

这个方法比较简单，就是一圈一圈的绘制园，越细分效果越好。

[zx095x]

前面 说过了，是 自上向下渐变

[Quote=引用 9 楼 veron_04 的回复:]
VB code

Private Sub Command1_Click()
Dim bytR As Byte
Dim bytG As Byte
Dim bytB As Byte
Dim hBrush As Long
Dim OldMode As Integer
Dim RetVal As Integer
Dim StepSi……
[/Quote]

[zx095x]

[lyserver]

使用GDI+渐变色画笔或GDI中的CreatePatternBrush函数创建一个渐变色画刷填充即可。

[zx095x]

无代码无真相

[Quote=引用 12 楼 lyserver 的回复:]
使用GDI+渐变色画笔或GDI中的CreatePatternBrush函数创建一个渐变色画刷填充即可。
[/Quote]

[贝隆]

Option Explicit
Private Const PI = 3.1415926
Private Sub btnDrawCircle_Click()
    Dim intR As Integer     '圆的半径
    Dim intRed As Integer   'RGB的R
    Dim intGreen As Integer 'RGB的G
    Dim intBlue As Integer  'RGB的B
    Dim intP As Long
    Dim X1 As Double
    Dim Y1 As Double
    Dim X2 As Double
    Dim Y2 As Double
    Dim delta As Double
On Error GoTo errSub
    intR = 2000
    intRed = 143
    intGreen = 122
    intBlue = 16
    Rem 细分数：1000
    delta = PI / 1000
    For intP = 0 To 1000
        X1 = intR * Cos(delta * intP)
        Y1 = intR * Sin(delta * intP)
        X2 = intR * Cos(-delta * intP)
        Y2 = intR * Sin(-delta * intP)
        picMap.Line (X1, Y1)-(X2, Y2), RGB(intRed / 1000 * intP, intGreen / 1000 * intP, intBlue / 1000 * intP)
    Next intP
    Exit Sub
errSub:
End Sub

Private Sub Form_Load()
    With picMap
        .Appearance = 0
        .AutoRedraw = True
        .FillStyle = 1
        .DrawMode = 13
        .DrawWidth = 5
        .Width = 8000
        .Height = 6000
    End With
    picMap.Scale (-4000, 3000)-(4000, -3000)    '定义坐标系统，图片正中心是（0，0）
End Sub

这个方法效率比较低，但很好理解。

[h3225518]

厉害啊

[贝隆]

上面的是从右到左的渐变效果
这个是从上到下的渐变效果

Option Explicit
Private Const PI = 3.1415926
Private Sub btnDrawCircle_Click()
    Dim intR As Integer     '圆的半径
    Dim intRed As Integer   'RGB的R
    Dim intGreen As Integer 'RGB的G
    Dim intBlue As Integer  'RGB的B
    Dim intP As Long
    Dim X1 As Double
    Dim Y1 As Double
    Dim X2 As Double
    Dim Y2 As Double
    Dim delta As Double
    Dim lngCount As Long
On Error GoTo errSub
    intR = 2000
    intRed = 143
    intGreen = 122
    intBlue = 16
    lngCount = 1000
    Rem 细分数：lngCount
    delta = PI / lngCount
    For intP = 0 To lngCount
        X1 = intR * Cos(delta * intP + PI * 0.5)
        Y1 = intR * Sin(delta * intP + PI * 0.5)
        X2 = intR * Cos(-delta * intP + PI * 0.5)
        Y2 = intR * Sin(-delta * intP + PI * 0.5)
        picMap.Line (X1, Y1)-(X2, Y2), RGB(intRed / lngCount * intP, intGreen / lngCount * intP, intBlue / lngCount * intP)
    Next intP
    Exit Sub
errSub:
End Sub

Private Sub Form_Load()
    With picMap
        .Appearance = 0
        .AutoRedraw = True
        .FillStyle = 1
        .DrawMode = 13
        .DrawWidth = 5
        .Width = 8000
        .Height = 6000
    End With
    picMap.Scale (-4000, 3000)-(4000, -3000)    '定义坐标系统，图片正中心是（0，0）
End Sub

[zx095x]

运行不了，不知道picMap是啥

[Quote=引用 16 楼 veron_04 的回复:]
上面的是从右到左的渐变效果
这个是从上到下的渐变效果

VB code

Option Explicit
Private Const PI = 3.1415926
Private Sub btnDrawCircle_Click()
Dim intR As Integer '圆的半径
Dim intRed As Integer 'RGB的R
D……
[/Quote]

[zx095x]

能按上图45度角渐变么？

[Quote=引用 17 楼 zx095x 的回复:]
运行不了，不知道picMap是啥


引用 16 楼 veron_04 的回复:
上面的是从右到左的渐变效果
这个是从上到下的渐变效果

VB code

Option Explicit
Private Const PI = 3.1415926
Private Sub btnDrawCircle_Click()
Dim intR As Integer '圆的半径
Dim ……
[/Quote]

[ao5212]

都是高人 学习了

[贝隆]

可按45°变换，picMap是PictureBox的名字，我按自己的习惯改了名称。

Option Explicit
Private Const PI = 3.1415926
Private Sub btnDrawCircle_Click()
    Dim intR As Integer     '圆的半径
    Dim intRed As Integer   'RGB的R
    Dim intGreen As Integer 'RGB的G
    Dim intBlue As Integer  'RGB的B
    Dim intP As Long
    Dim X1 As Double
    Dim Y1 As Double
    Dim X2 As Double
    Dim Y2 As Double
    Dim delta As Double
    Dim lngCount As Long
On Error GoTo errSub
    intR = 2000
    intRed = 143
    intGreen = 122
    intBlue = 16
    lngCount = 1000
    Rem 细分数：lngCount
    delta = PI / lngCount
    For intP = 0 To lngCount
        X1 = intR * Cos(delta * intP + PI * 0.25)
        Y1 = intR * Sin(delta * intP + PI * 0.25)
        X2 = intR * Cos(-delta * intP + PI * 0.25)
        Y2 = intR * Sin(-delta * intP + PI * 0.25)
        picMap.Line (X1, Y1)-(X2, Y2), RGB(intRed / lngCount * intP, intGreen / lngCount * intP, intBlue / lngCount * intP)
    Next intP
    Exit Sub
errSub:
End Sub

Private Sub Form_Load()
    With picMap
        .Appearance = 0
        .AutoRedraw = True
        .FillStyle = 1
        .DrawMode = 13
        .DrawWidth = 1
        .Width = 8000
        .Height = 6000
    End With
    picMap.Scale (-4000, 3000)-(4000, -3000)    '定义坐标系统，图片正中心是（0，0）
End Sub

[贝隆]

上面是按右侧45°渐变

[zx095x]

要求左上角最淡，怎么改？有QQ么？

[Quote=引用 21 楼 veron_04 的回复:]
上面是按右侧45°渐变
[/Quote]

[贝隆]

18037803