VB API 之 第七课 字体应用四

SelectClipRgn

功能：选取一个区域新的剪切区域

Declare Function SelectClipRgn Lib "gdi32" Alias "SelectClipRgn" (ByVal hdc As Long, ByVal hRgn As Long) As Long

参数

hdc：设备环境句柄。

hrgn：标识被选择的区域。

返回值：返回一个剪辑区域复杂度，可以是下列值之一。

NULLREGION：区域为空；

SIMPLEREGION：区域为单个矩形；

COMPLEXREGION：区域为多个矩形；

ERROR：发生错误（以前的剪切区域不受影响）。

CreateRectRgn

创建一个由点X1，Y1和X2，Y2描述的矩形区域

Declare Function CreateRectRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long

参数

X1,Y1 Long，矩形左上角X，Y坐标

X2,Y2 Long，矩形右下角X，Y坐标

返回值

执行成功为区域句柄，失败则为零

 

SetTextAlign

该函数为指定设备环境设置文字对齐

Declare Function SetTextAlign Lib "gdi32" Alias "SetTextAlign" (ByVal hdc As Long, ByVal wFlags As Long) As Long

参数

HDC hdc, // 设备环境句柄

UINT fMode // 文本对齐选项

TA_BASELINE

基准点在正文的基线上。

TA_BOTTOM

基准点在限定矩形的下边界上。

TA_TOP

基准点在限定矩形的上边界上。

TA_CENTER

基准点与限定矩形的中心水平对齐。

TA_LEFT

基准点在限定矩形的左边界上。

TA_RIGHT

基准点在限定矩形的右边界上。

TA_RTLREADING

对于中东Windows版，正文从右到左的阅读顺序排列，与缺省的从左到右正好相反。

只有当被选择的字体是Hebrew或Arabic时，此值才有用。

TA_NOUPDATECP

每次文字输出调用后当前基准点不改变。基准点是传输给正文输出函数的位置。

TA_UPDATECP

每次文字输出调用后当前基准点改变。当前位置作为基准点。

若当前字体有一条缺省的垂直基线（如Kanji），下列值用于取代TA_BASELINE和TA_CENTER，各值含义为：

VTA_BASELINE

基准点在正文的基线上。

VTA_CENTER

基准点与限定矩形的中心垂直对齐。

缺省值是TA_LEFT, TA_TOP和TA_NOUPDATECP。

如果函数调用成功，返回值是文字对齐方式的前一个设置；

如果函数调用失败，返回值是GDI_ERROR

文本应用示例 

Option Explicit

Private Declare Function SelectClipRgn Lib "gdi32" (ByVal hdc As Long, ByVal hRgn As Long) As Long
Private Declare Function CreateRectRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function SetTextColor Lib "gdi32" (ByVal hdc As Long, ByVal crColor As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function CreateFontIndirect Lib "gdi32" Alias "CreateFontIndirectA" (lpLogFont As LOGFONT) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function SetTextAlign Lib "gdi32" (ByVal hdc As Long, ByVal wFlags As Long) As Long
Private Declare Function TextOut Lib "gdi32" Alias "TextOutA" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal lpString As String, ByVal nCount As Long) As Long
Private Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
  Private Const TA_LEFT = 0
  Private Const TA_RIGHT = 2
  Private Const TA_CENTER = 6
  Private Const TA_TOP = 0
  Private Const TA_BOTTOM = 8
  Private Const TA_BASELINE = 24
Private Type LOGFONT
lfHeight As Long
lfWidth As Long
lfEscapement As Long
lfOrientation As Long
lfWeight As Long
lfItalic As Byte
lfUnderline As Byte
lfStrikeOut As Byte
lfCharSet As Byte
lfOutPrecision As Byte
lfClipPrecision As Byte
lfQuality As Byte
lfPitchAndFamily As Byte
lfFaceName As String * 50
End Type
Private m_LF As LOGFONT
Private NewFont As Long
Private OrgFont As Long
Public Sub CharPlace(o As Object, txt, x, y)
Dim Throw As Long
Dim hregion As Long
Dim R As RECT
R.Left = x
     R.Right = x + o.TextWidth(txt) * 2
R.Top = y
R.Bottom = y + o.TextHeight(txt) * 2
hregion = CreateRectRgn(R.Left, R.Top, R.Right, R.Bottom)
Throw = SelectClipRgn(o.hdc, hregion)
Throw = TextOut(o.hdc, x, y, txt, Len(txt))
DeleteObject (hregion)
End Sub
Public Sub SetAlign(o As Object, Top, BaseLine, Bottom, Left, Center, Right)
Dim Vert As Long
Dim Horz As Long
If Top = True Then Vert = TA_TOP
If BaseLine = True Then Vert = TA_BASELINE
If Bottom = True Then Vert = TA_BOTTOM
If Left = True Then Horz = TA_LEFT
If Center = True Then Horz = TA_CENTER
If Right = True Then Horz = TA_RIGHT
SetTextAlign o.hdc, Vert Or Horz
End Sub
    Public Sub setcolor(o As Object, CValue As Long)
Dim Throw As Long
Throw = SetTextColor(o.hdc, CValue)
End Sub
Public Sub SelectOrg(o As Object)
Dim Throw As Long
NewFont = SelectObject(o.hdc, OrgFont)
Throw = DeleteObject(NewFont)
End Sub
Public Sub SelectFont(o As Object)
NewFont = CreateFontIndirect(m_LF)
OrgFont = SelectObject(o.hdc, NewFont)
End Sub
    Public Sub FontOut(text, o As Control, XX, YY)
Dim Throw As Long
Throw = TextOut(o.hdc, XX, YY, text, Len(text))
End Sub
Public Property Get Width() As Long
Width = m_LF.lfWidth
End Property
    Public Property Let Width(ByVal W As Long)
m_LF.lfWidth = W
End Property
Public Property Get Height() As Long
Height = m_LF.lfHeight
End Property
    Public Property Let Height(ByVal vNewValue As Long)
m_LF.lfHeight = vNewValue
End Property
Public Property Get Escapement() As Long
Escapement = m_LF.lfEscapement
End Property
    Public Property Let Escapement(ByVal vNewValue As Long)
m_LF.lfEscapement = vNewValue
End Property
Public Property Get Weight() As Long
Weight = m_LF.lfWeight
End Property
    Public Property Let Weight(ByVal vNewValue As Long)
m_LF.lfWeight = vNewValue
End Property
Public Property Get Italic() As Byte
Italic = m_LF.lfItalic
End Property
    Public Property Let Italic(ByVal vNewValue As Byte)
m_LF.lfItalic = vNewValue
End Property
Public Property Get UnderLine() As Byte
UnderLine = m_LF.lfUnderline
End Property
    Public Property Let UnderLine(ByVal vNewValue As Byte)
m_LF.lfUnderline = vNewValue
End Property
Public Property Get StrikeOut() As Byte
StrikeOut = m_LF.lfStrikeOut
End Property
    Public Property Let StrikeOut(ByVal vNewValue As Byte)
m_LF.lfStrikeOut = vNewValue
End Property
Public Property Get FaceName() As String
FaceName = m_LF.lfFaceName
End Property
    Public Property Let FaceName(ByVal vNewValue As String)
m_LF.lfFaceName = vNewValue
End Property
Private Sub Class_Initialize()
m_LF.lfHeight = 15
m_LF.lfWidth = 15
m_LF.lfEscapement = 0
m_LF.lfWeight = 400
m_LF.lfItalic = 0
m_LF.lfUnderline = 0
m_LF.lfStrikeOut = 0
m_LF.lfOutPrecision = 0
m_LF.lfClipPrecision = 0
m_LF.lfQuality = 0
m_LF.lfPitchAndFamily = 0
m_LF.lfCharSet = 0
m_LF.lfFaceName = "Arial" + Chr(0)
End Sub

消息响应函数

Option Explicit
Dim af As APIFont
Dim x, y As Integer

Private Sub cmdAngle_Click()
Dim i As Integer
Set af = Nothing
Set af = New APIFont
Picture1.Cls
     For i = 0 To 3600 Step 90
af.Escapement = i
af.SelectFont Picture1
x = Picture1.ScaleWidth / 2
y = Picture1.ScaleHeight / 2
af.FontOut "Comrade Studio", Picture1, x, y
af.SelectOrg Picture1
Next i
End Sub

Private Sub cmdHeight_Click()
  Dim i As Integer
Set af = Nothing
Set af = New APIFont
Picture1.Cls
     For i = 0 To 360 Step 1
Picture1.Cls
af.Height = i
af.SelectFont Picture1
x = Picture1.ScaleWidth / 2
y = Picture1.ScaleHeight / 2
af.FontOut "Comrade Studio", Picture1, x, y
af.SelectOrg Picture1
Next i
End Sub

Private Sub cmdWeight_Click()
Dim i As Integer
i = 0
Set af = Nothing
Set af = New APIFont
Picture1.Cls
     For i = 0 To 3600 Step 1
Picture1.Cls
af.Weight = i * 5
af.SelectFont Picture1
x = Picture1.ScaleWidth / 2
y = Picture1.ScaleHeight / 2
af.FontOut "Comrade Studio", Picture1, x, y
af.SelectOrg Picture1
Next i
End Sub

Private Sub cmdWidth_Click()
Dim i As Integer
Set af = Nothing
Set af = New APIFont
Picture1.Cls
     For i = 0 To 360 Step 1
Picture1.Cls
af.Width = i
af.SelectFont Picture1
x = Picture1.ScaleWidth / 2
y = Picture1.ScaleHeight / 2
'在字符串后面要加入5个空格
af.FontOut "同志工作室     ", Picture1, x, y
af.SelectOrg Picture1
Next i
End Sub



Private Sub Form_Load()
Picture1.ScaleMode = 3
End Sub

运行结果如图：