printer如何使用drawtext这个API涵数
以下内容：
call drawtext(obj.hdc,"aaa",-,trc,tformat)
当obj为picturebox时，可以画出aaa这个字符在对应的trc里面，但当obj为printer时，却打印不出来，我查了一些相关的内容，确实有这种情况，也看过有个方法是先在drawtext运行之前加入obj.line (0,0)-(100,100),vbwhite进行先画线来激活printer，但我试了还是不行，请问各位还有什么好方法能让drawtext可以使用printer对象呢？
如果没有，那能用哪个API代替drawtext呢？（必须能定义水平对齐、自动换行等方式，因为编写的需要）
衷心感激各位！
[解决办法]
我使用drawtext打印，一切正常
[解决办法]
'Example Name: Changing the Dropdown Width of a Combo Box, Advanced'------------------------------------------'' BAS Moduel Code''------------------------------------------Option ExplicitPublic Declare Function SendMessage Lib "user32" _ Alias "SendMessageA" _ (ByVal hwnd As Long, _ ByVal wMsg As Long, _ ByVal wParam As Long, _ lParam As Long) As LongPublic Const CB_GETLBTEXTLEN = &H149Public Const CB_SHOWDROPDOWN = &H14FPublic Const CB_GETDROPPEDWIDTH = &H15FPublic Const CB_SETDROPPEDWIDTH = &H160Public Const ANSI_FIXED_FONT = 11Public Const ANSI_VAR_FONT = 12Public Const SYSTEM_FONT = 13Public Const DEFAULT_GUI_FONT = 17 'win95/98 onlyPublic Const SM_CXHSCROLL = 21Public Const SM_CXHTHUMB = 10Public Const SM_CXVSCROLL = 2Public Type SIZE cx As Long cy As LongEnd TypePublic Type RECT Left As Long Top As Long Right As Long Bottom As LongEnd TypePublic Declare Function DrawText Lib "user32" _ Alias "DrawTextA" _ (ByVal hDC As Long, _ ByVal lpStr As String, _ ByVal nCount As Long, _ lpRect As RECT, _ ByVal wFormat As Long) As LongPublic Const DT_CALCRECT = &H400Public Declare Function SelectObject Lib "gdi32" _ (ByVal hDC As Long, ByVal hObject As Long) As LongPublic Declare Function GetTextExtentPoint32 Lib "gdi32" _ Alias "GetTextExtentPoint32A" _ (ByVal hDC As Long, _ ByVal lpsz As String, _ ByVal cbString As Long, _ lpSize As SIZE) As LongPublic Declare Function GetStockObject Lib "gdi32" _ (ByVal nIndex As Long) As Long Public Declare Function DeleteObject Lib "gdi32" _ (ByVal hObject As Long) As Long Public Declare Function ReleaseDC Lib "user32" _ (ByVal hwnd As Long, _ ByVal hDC As Long) As Long Public Declare Function GetDC Lib "user32" _ (ByVal hwnd As Long) As Long Public Declare Function GetSystemMetrics Lib "user32" _ (ByVal nIndex As Long) As LongPublic Function GetFontDialogUnits() As Long Dim hFont As Long Dim hFontOld As Long Dim r As Long Dim avgWidth As Long Dim hDc As Long Dim tmp As String Dim sz As SIZE 'get the hdc to the main window hDc = GetDC(Form1.hwnd) 'with the current font attributes, select the font hFont = GetStockObject(ANSI_VAR_FONT) hFontOld = SelectObject(hDc, hFont&) 'get its length, then calculate the average character width tmp = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" GetTextExtentPoint32(hDc, tmp, 52, sz) avgWidth = (sz.cx \ 52) 're-select the previous font & delete the hDc SelectObject(hDc, hFontOld) DeleteObject(hFont) ReleaseDC(Form1.hwnd, hDc) 'return the average character width GetFontDialogUnits = avgWidthEnd Function'--end block--''------------------------------------------'' Form Code''------------------------------------------Option ExplicitPrivate Sub Command1_Click() Dim cwidth As Long Dim NewDropDownWidth As Long 'check if a number is entered into Text1. 'If not, bail out. If Val(Text1.Text) 'here we simply set the dropdown list size to 'the value entered in Text1. Note: If the proposed 'width this is less than the width of the combo 'portion, the combo width is used (the dropdown 'can never be narrower than the combobox) NewDropDownWidth = Val(Text1.Text) 'resize the dropdown portion of the combo box using SendMessage Call SendMessage(Combo1.hwnd, CB_SETDROPPEDWIDTH, NewDropDownWidth, ByVal 0) 'reflect the new dropdown list width in the Label cwidth = SendMessage(Combo1.hwnd, CB_GETDROPPEDWIDTH, 0, ByVal 0) Label1.Caption = "Current dropdown width = " & cwidth & " pixels." 'drop the list down by code to show the new size Call SendMessage(Combo1.hwnd, CB_SHOWDROPDOWN, True, ByVal 0)End SubPrivate Sub Command2_Click() Dim cwidth As Long Dim i As Long Dim NumOfChars As Long Dim LongestComboItem As Long Dim avgCharWidth As Long Dim NewDropDownWidth As Long 'loop through the combo entries, using SendMessage 'with CB_GETLBTEXTLEN to determine the longest item 'in the dropdown portion of the combo For i = 0 To Combo1.ListCount - 1 NumOfChars = SendMessage(Combo1.hwnd, CB_GETLBTEXTLEN, i, ByVal 0) If NumOfChars > LongestComboItem Then LongestComboItem = NumOfChars Next 'get the average size of the characters using the 'GetFontDialogUnits API. Because a dummy string is 'used in GetFontDialogUnits, avgCharWidth is an 'approximation based on that string. avgCharWidth = GetFontDialogUnits() 'compute the size the dropdown needs to be to accommodate 'the longest string. Here I subtract 2 because I find that 'on my system, using the dummy string in GetFontDialogUnits, 'the width is just a bit too wide. NewDropDownWidth = (LongestComboItem - 2) * avgCharWidth 'resize the dropdown portion of the combo box Call SendMessage(Combo1.hwnd, CB_SETDROPPEDWIDTH, NewDropDownWidth, ByVal 0) 'reflect the new dropdown list width in Label2 and in Text1 cwidth = SendMessage(Combo1.hwnd, CB_GETDROPPEDWIDTH, 0, ByVal 0) Label1.Caption = "Current dropdown width = " & cwidth & " pixels." Text1.Text = cwidth 'finally, drop the list down by code to show the new size Call SendMessage(Combo1.hwnd, CB_SHOWDROPDOWN, True, ByVal 0)End Sub
