又一个用VB编写ActiveX自定义控件的例子——进度条控件

设计方法：

1.在UserControl中添加一个Label控件Label1，将它设为平面，用来做外框。添加两个PictureBox控件PictureBox1做为进度指示，PictureBox2控件做为控件背景。

2.加入以下代码

Option Explicit

''定义私有变量用于存储属性值
Private mvarMax As Long
Private mvarMin As Long
Private mvarValue As Long

Private Rate As String

Private Sub UserControl_Initialize()
''初始化
Picture2.BackColor = vbBlue
End Sub

Public Property Get BackColor() As OLE_COLOR
''读取BackColor属性
BackColor = Picture1.BackColor
End Property

Public Property Let BackColor(ByVal vNewValue As OLE_COLOR)
''设置BackColor属性
Picture1.BackColor = vNewValue
End Property

Private Sub UserControl_InitProperties()
''初始化属性
Max = 100
Min = 0
Value = 0
End Sub

Private Sub UserControl_ReadProperties(PropBag As PropertyBag)
''读取从属性窗体中设置的属性值
mvarMax = PropBag.ReadProperty("Max", 100)
mvarMin = PropBag.ReadProperty("Min", 0)
''Value属性值这里未提供，主要是模仿VB自带的进度条控件
''mvarValue = PropBag.ReadProperty("Value", 0)
End Sub

Private Sub UserControl_WriteProperties(PropBag As PropertyBag)
''保存从属性窗体中设置的属性值
PropBag.WriteProperty "Max", mvarMax, 100
PropBag.WriteProperty "Min", mvarMin, 0
''PropBag.WriteProperty "Value", mvarValue, 0
End Sub

Private Sub UserControl_Resize()
''Resize事件
Label1.Move 0, 0, UserControl.Width / Screen.TwipsPerPixelX, UserControl.Height / Screen.TwipsPerPixelY
Picture1.Move 1, 1, UserControl.Width / Screen.TwipsPerPixelX - 2, UserControl.Height / Screen.TwipsPerPixelY - 2
Picture2.Move 1, 1, 1, UserControl.Height / Screen.TwipsPerPixelY - 2
End Sub

Public Property Get Max() As Long
''读取Max属性
Max = mvarMax
End Property

Public Property Let Max(ByVal vNewValue As Long)
''设置Max属性
mvarMax = vNewValue
If vNewValue < Min Then Err.Raise "1001", , "Max必须大于Min"
End Property

Public Property Get Min() As Long
''读取Min属性
Min = mvarMin
End Property

Public Property Let Min(ByVal vNewValue As Long)
''设置Min属性
If vNewValue > Max Then Err.Raise "1000", , "Min必须小于Max"
mvarMin = vNewValue
End Property

Public Property Get Value() As Long
''读取Value属性
Value = mvarValue
End Property

Public Property Let Value(ByVal vNewValue As Long)
''设置Value属性
''原理就是在两个PictureBox中以不同颜色打印百分比进度
Dim DX As Long, DY As Long

If vNewValue > Max Then Err.Raise "1002", , "Value不能大于Max"
mvarValue = vNewValue

Picture2.Width = Value / (Max - Min) * (UserControl.Width / Screen.TwipsPerPixelX - 2)
Rate = Int(Value / (Max - Min) * 100) & "%"
DX = (Picture1.Width - Picture1.TextWidth(Rate)) / 2
DY = (Picture1.Height - Picture1.TextHeight(Rate)) / 2
Picture1.ForeColor = vbBlack
Picture2.ForeColor = vbWhite
If DX < Picture2.Width Then
Picture2.Cls
Picture2.CurrentX = DX
Picture2.CurrentY = DY
Picture2.Print Rate
Else
Picture1.Cls
Picture1.CurrentX = DX
Picture1.CurrentY = DY
Picture1.Print Rate
End If
End Property

3.新建另一个测试工程，加入一个自己的进度条控件和一个系统的进度条控件，加入以下代码：

Option Explicit

Private Sub Command1_Click()
Unload Me
End Sub

Private Sub Timer1_Timer()
myProgressBar1.Value = myProgressBar1.Value + 2
ProgressBar1.Value = ProgressBar1.Value + 2
If myProgressBar1.Value = myProgressBar1.Max Then Timer1.Enabled = False
End Sub

OK.运行看看效果吧。