在TextBox中是否可以对文本进行对齐 (不是居中)?我知道
Justify (两端对齐)
txt.TextAlign = HorizontalAlignment.Left;
例如,但是左右两端都对齐的可能吗?
在TextBox中是否可以对文本进行对齐 (不是居中)?我知道
Justify (两端对齐)
txt.TextAlign = HorizontalAlignment.Left;
这是一个很棘手的问题,正如先前所述,需要一个自定义控件来解决。然而,如果你像我一样只想在对话框或关于框中显示文本框数据(例如居中显示),那么可以使用PictureBox并将其渲染到其中,同时保持实际的文本框隐藏。需要将空格替换为特殊代码以指示间距的像素宽度。作为许多打印机驱动程序的老手,这对我来说已经很熟悉了。我将在下面提供执行此操作的代码,尽管我不确定它在此网页上的呈现效果如何。也许他们可以重新格式化它,或者如果他们要求,我会发送给他们原始代码。虽然我是一名汇编语言和C/C++开发人员,但我已经爱上了VB.NET,并用VB编写了它(我可以在两个小时内完成以前需要两周才能完成的工作)。
要使用这段代码,包括一个JustifyTextBox()方法和一个JustifyText_Paint()事件,只需放置所需的文本框并按照您想要的格式进行格式化。然后通过提供文本框调用JustifyTextBox()方法,例如JustifyTextBox(Me.MyTextBox),就可以开始工作了。它会处理所有PictureBox对象的创建和绘制工作。您可以将其应用于所需的任意数量的文本框。它不仅限于一个对象(这将违背面向对象的范例,无论如何)。
以下是所需的两个方法:
'*******************************************************************************
' Method Name : JustifyTextBox
' Copyright (c) David Ross GOben March 10, 2013. All rights reserved.
'
' Purpose : Reformat spacing in a textbox to allow for variable spacing, exactly
' : as a printer driver will process spacing for justification.
' : Having written many dozens of printer drivers over the years, this
' : is old hat. By the way, though you can do this with a RichTextBox,
' : you really should consider interpreting the RTF code to properly
' : render everything else, otherwise, if you were to simply replace
' : the TextBox casting to a RichTextBox, it would only process the
' : data from its Text property, so pretty text and coloring and font
' : typeface, size, and enhancements will not display in the PictureBox.
'*******************************************************************************
' Set up your code to use the JustifyTextBox() method and the JustifyText_Paint() event like this:
'
' JustifyTextBox(TextBoxObjectToJustify) 'create a PictureBox control to justify the text, and hide this TextBox
' 'This will also link the created PictureBox's Paint() event to JustifyText_Paint
'-------------------------------------------------------------------------------
' NOTE: You can duplicate the above code for as many text boxes as you require.
' Also, there is no need to render them ReadOnly, because the user will not
' be able to access them through the user itnerface.
'*******************************************************************************
Private Sub JustifyTextBox(ByRef TxtBox As TextBox)
Dim picImage As PictureBox = New PictureBox 'create a PictureBox object (The textBox data will be painted to this)
With picImage
.Location = TxtBox.Location 'locate the PictureBox to the provided TextBox control
.Size = TxtBox.Size 'size it to the textbox boundaries
.Tag = TxtBox 'save a reference to the textbox for use during printing
.Parent = TxtBox.Parent 'set parent so it will display when the parent is displayed
AddHandler picImage.Paint, AddressOf JustifyText_Paint 'attach an event handler to the picture box's paint event
TxtBox.Visible = False 'render the associated textbox invisible
End With
'=======================================================================
With TxtBox
Dim TextSize As Size = TextRenderer.MeasureText("W y", .Font) 'get pixel width of "W y"
Dim Yinc As Int32 = TextSize.Height 'get vertical spacing to increment lines
Dim SpcSize As Int32 = TextSize.Width 'save measurement (we will adust the Space Size variable property in a second)
TextSize = TextRenderer.MeasureText("Wy", .Font) 'get pixel width of "Wy", without the space
SpcSize = SpcSize - TextSize.Width - 1 'compute the width of a space (drop 1 more for proper rendering)
Dim SpcInit As Int32 = 128 + SpcSize 'initial size of space and ecoding of space codes (spacing size + 128)
Dim CurlineIdx, NxtLineIdx, cAsc As Int32 'used variables
Dim LastLine As Int32 = .GetLineFromCharIndex(Len(.Text)) 'get the last line index of the TextBox, offset from zero
Dim Result As String = Nothing 'init encoded result
Dim Txt As String = Nothing 'string to hold each line of text in the TextBox
Dim Tmptext As String 'copy of Txt that is altered
For Idx As Int32 = 0 To LastLine 'process each line (offset from 0)
CurlineIdx = .GetFirstCharIndexFromLine(Idx) 'get start of the indicated line number line
If Idx = LastLine Then 'at the last line of text data in the TextBox (if so, we do not need to justify it?
Txt = RTrim(.Text.Substring(CurlineIdx)) 'yes, so simply grab the text of the line from the start character index to the end of the text data
Tmptext = Txt 'make a copy to TmpText
Else 'otherwise... grab the current line of text from the TextBox
NxtLineIdx = .GetFirstCharIndexFromLine(Idx + 1) 'not the last line, so get the index to the start of the next line
Txt = RTrim(.Text.Substring(CurlineIdx, NxtLineIdx - CurlineIdx)) 'grab the text of the current line. Also remove any trailing spaces
If Len(Txt) <> 0 AndAlso VB.Right(Txt, 2) = vbCrLf Then 'does the current line end with CR/LF?
Tmptext = RTrim(VB.Left(Txt, Len(Txt) - 2)) 'yes, so strip CR/LF and strip any spaced leading them. There is no need to justify this line
ElseIf Len(Txt) = 0 Then 'otherwise, if the text notains NO data...
Tmptext = Nothing 'then simply make the line blank and do nothing else
Else 'otherwise... we have to encode the line to justify it
Tmptext = Txt 'get a copy of this string, which we will use to encode
TextSize = TextRenderer.MeasureText(Tmptext, .Font) 'get its current size
Dim SpcNeeded As Int32 = .Width - TextSize.Width 'compute number of pixels to add
If SpcNeeded > 0 Then 'do we need to add spacing? (allow for negative result)
Tmptext = Join(Split(Tmptext, " "), Chr(SpcInit)) 'yes, so first replace spaces with special code for point-size spacing
Dim Idy As Int32 = 1 'init column start index (used to skip over leading spaces)
Do While Asc(Mid(Tmptext, Idy, 1)) > 127
Idy += 1 'skip past leading spaces (indent)
Loop
'---------------------------------------------------
Dim AddedSpacing As Boolean = False 'set up a flag to deterct if we added any spacing to the line
Do While SpcNeeded <> 0 'now loop through and add a pixel to each space in the text until there are none left to add
For Idz As Int32 = Idy To Len(Tmptext) 'scan through line data
cAsc = Asc(Mid(Tmptext, Idz, 1)) 'get code
If cAsc > 127 Then 'special space character?
cAsc += 1 'add 1 pixel to its size
Mid(Tmptext, Idz, 1) = Chr(cAsc) 'stuff result back
AddedSpacing = True
SpcNeeded -= 1 'drop 1 from count of spacing needed
If SpcNeeded = 0 Then 'have we added all the spaces we need?
Exit For 'yes, so do not add any more
End If
End If
Next
If Not AddedSpacing Then 'if we could not add any space...
Exit Do 'then exit the loop
End If
AddedSpacing = False
'-----------------------------------------------
Loop 'loop through the line again to add additional spacing
End If
End If
End If
'---------------------------------------------------------------
Result &= vbCrLf & Tmptext 'add TmpText data, manipulated or not, to the Result accumulator string
Next 'process the next line of code
.Text = Mid(Result, 3) 'stuff the result back to the TextBox for storage, less the leading CR+LF
End With
End Sub
'*******************************************************************************
' Method Name : JustifyText_Paint
' Purpose : Draw text from a textbox onto a PictureBox control (created in the
' : setup code), using special spacing codes inserted by JustifyTextBox().
' :
' NOTE : A reference to the associated Textbox is stored in the PictureBox's Tag property
'*******************************************************************************
' NOTE: You may notice that we seem to add 1 pixel to the width of the space character,
' below, but we subtracted 1 pixel in the the JustifyTextBox() method. This is
' originally subtracting 1. It also allows the right margin to reamin at its
' straightest. I realize that this actually has to do something with the margins
' applied in the TextRender.MeasureText() process, and even though I have tried to
' set theTextFormatFlags to NoPadding and in various other ways, and even none
' at all (as it is now), it dors not make one bit of difference, at all. However,
' on average, with or without using the TextFormatFlags, if we subtract a pixel from
' the space size and subtract 6 (typical margin of 3 pixels on either side) from
' measuring each word, the alignment is about perfect. However, a side effect is
' that some long words seem to almost butt up against a fllowing word. A hack around
' that is to simply manually insert an extra space between these words in the textbox.
'*******************************************************************************
Private Sub JustifyText_Paint(sender As Object, e As PaintEventArgs)
With DirectCast(DirectCast(sender, PictureBox).Tag, TextBox)
Dim TextSize As Size = TextRenderer.MeasureText("X y", .Font) 'get size of sample text
Dim Yinc As Single = CSng(TextSize.Height) 'keep height for adding lines in the picturebox
Dim SpcSize As Single = CSng(TextSize.Width) 'save the length result
TextSize = TextRenderer.MeasureText("Xy", .Font) 'grab the same text, but without the space (drop 1 more for proper rendering)
SpcSize = SpcSize - CSng(TextSize.Width + 1) 'compute space width (we are actually subtracting an addtional pixel)
Dim txtMargin As Single = CSng(.Margin.Left + .Margin.Right) 'compute the margin allowance (MeasureText adds this to the width)
Dim PosnX As Single = CSng(e.ClipRectangle.Left) 'start postion to draw text in the picturebox
Dim PosnY As Single = CSng(e.ClipRectangle.Top)
Dim Tmptxt As String = Nothing 'init temporary text holder
Dim Brsh As New SolidBrush(.ForeColor) 'get the brush for the text color to use from the textbox
For Idx As Int32 = 1 To Len(.Text) 'scan each character in the master text
Dim iChar As Int32 = Asc(Mid(.Text, Idx, 1)) 'grab the cascii code for the currently indexed character
Select Case iChar
Case Is > 127 'special spacing character?
If Len(Tmptxt) <> 0 Then 'yes, so dump the temp text if it has accumulated data
TextSize = TextRenderer.MeasureText(Tmptxt, .Font) 'first grab the size of the text
e.Graphics.DrawString(Tmptxt, .Font, Brsh, PosnX, PosnY) 'then draw it
PosnX += CSng(TextSize.Width - txtMargin) 'then bump the x offset, less the margin allowance
Tmptxt = Nothing 'clear the temp text buffer
End If
PosnX += CSng((iChar And 127)) 'finally, bump the x offset by the spaceing code (pixel count + 128)
Case 13 'vbCr?
If Len(Tmptxt) <> 0 Then 'yes, so dump the temp text if it has accumulated data
e.Graphics.DrawString(Tmptxt, .Font, Brsh, PosnX, PosnY) 'then draw it
Tmptxt = Nothing 'clear the temp text buffer
End If
PosnX = CSng(e.ClipRectangle.Left) 'reset the X offset to the left side
PosnY += Yinc 'bump the line index to the next line position
Case 32 'Space?
If Len(Tmptxt) <> 0 Then 'yes, so dump the temp text if it has accumulated data
TextSize = TextRenderer.MeasureText(Tmptxt, .Font) 'first grab the size of the text
e.Graphics.DrawString(Tmptxt, .Font, Brsh, PosnX, PosnY) 'then draw it
PosnX += CSng(TextSize.Width - txtMargin) 'then bump the x offset, less the margin allowance
Tmptxt = Nothing 'clear the temp text buffer
End If
PosnX += SpcSize 'bump index by a space size
Case 10 'vbLf? If so, ignore it
Case Else 'normal character
Tmptxt &= Chr(iChar) 'add the character to the temp text buffer
End Select
Next
If Len(Tmptxt) <> 0 Then 'dump the temp text if it has accumulated data
e.Graphics.DrawString(Tmptxt, .Font, Brsh, PosnX, PosnY) 'then draw it
End If
Brsh.Dispose() 'finally, dispose of the used brush resource
End With
End Sub
对齐方式可以设置为居中,以便左右两端对齐
textBox1.TextAlign = HorizontalAlignment.Center;