Question

如何让用VB制作一个简单的画图板???有简单的制作过程和源代码......求高人指导！

要求当按下鼠标左键时能在窗体上画出对应的线条，且可以改变线条的颜色和粗细，就这三个要求

Answer 1

Dim a As Double
Dim b As Double
Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
a = X
b = Y
End Sub
Private Sub Form_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button <> 1 Then Exit Sub
Me.Line (a, b)-(X, Y)
a = X
b = Y
End Sub
Private Sub Label1_Click(Index As Integer) '多放几个背景色不同的label1()控件组
Me.ForeColor = Label1(Index).BackColor
End Sub
Private Sub Text1_Change() '根据输入的数字改变线条宽度
Me.DrawWidth = Val(Text1.Text)
End Sub
'自己刚调试的代码，希望能帮助到你。

Answer 2

'form1窗体内放置两个TextBox和一个Picturebox
'代码只是演示了简单画图板画线功能，可变色，粗细。
'说明：text1 设置色，text2 设置粗细，Picture1只用作后台画图板，form1作显示图板。
Option ExplicitDim x1 As Long, y1 As Long, x2 As Long, y2 As Long, Col As Long, Bi As Long
Private Sub Form_Load()
Picture1.Visible = False
Picture1.AutoRedraw = True
Picture1.BorderStyle = 0
Picture1.Appearance = 0

Bi = Form1.DrawWidth
Col = vbBlack

Text1.Text = Col
Text2.Text = Bi
End Sub

Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button = vbKeyLButton Then
x1 = X
y1 = Y

End If
End Sub

Private Sub Form_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button = vbKeyLButton Then
x2 = X
y2 = Y
Cls
PaintPicture Picture1.Image, 0, 0
Line (x1, y1)-(x2, y2), Col
End If
End Sub

Private Sub Form_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button = vbKeyLButton Then
Picture1.Line (x1, y1)-(x2, y2), Col
End If
End Sub

Private Sub Form_Paint()
Picture1.Move 0, 0, Form1.ScaleWidth, Form1.ScaleHeight

End Sub

Private Sub Text1_Change()
On Error Resume Next
Col = CLng(Text1.Text) '设置色
End Sub

Private Sub Text2_Change()
On Error Resume Next
Bi = CLng(Text2.Text) '设置粗细
Form1.DrawWidth = Bi
Picture1.DrawWidth = Bi

End Sub

追问

您好，我按照你给我的程序运行后只能画出直线，不能画曲线，而且线条的颜色不能改变，只能变线条的粗细，有什么需要改的地方吗？能帮忙指导一下嘛？

追答

col 变量 用来设置颜色。
颜色的值可用：
rgb(0-255,0-255,0-255) 表示，如：rgb(255,0,0) 是红色；rgb(0,255,0)是绿色

画曲线，复杂些：
画的只是曲线（非弧线），在上述代码的基础上，定义几个动态储存点，捕捉鼠标的双击事件，用它来确定曲线的最终点。