richtextbox中的setselction字體大小vb.net中的多種字體

Question

我想使用組合框在richtextbox中更改爲字體大小，如果我們在使用此代碼的選擇文本中有一種字體，則可以輕鬆更改字體大小。

RichTextBox1.SelectionFont = New Font(SelectionFont.FontFamily, CInt(ToolStripComboBox3.Text), RichTextBox1.SelectionFont.Style) 

但是，如果我們在我們選擇多種字體也沒有作用。我有另一個代碼來解決這個問題。但是這個代碼的唯一問題是少於2000個字符，但是當選擇文本很大時，它是毫無價值的。代碼如下。任何幫助......

Public rtbTemp As New RichTextBox() 
    Public Sub ChangeFontSize(ByVal rtb As RichTextBox, ByVal fontSize As Single) 
     'This method should handle cases that occur when multiple fonts/styles are selected 
     ' Parameters:- 
     ' fontSize - the fontsize to be applied, eg 33.5 
     If fontSize <= 0.0 Then 
      Throw New System.InvalidProgramException("Invalid font size parameter to ChangeFontSize") 
     End If 
     Dim rtb1start As Integer = rtb.SelectionStart 
     Dim len As Integer = rtb.SelectionLength 
     Dim rtbTempStart As Integer = 0 
     ' If len <= 1 and there is a selection font, amend and return 
     If len <= 1 AndAlso rtb.SelectionFont IsNot Nothing Then 
      rtb.SelectionFont = New Font(rtb.SelectionFont.FontFamily, fontSize, rtb.SelectionFont.Style) 
      Return 
     End If 
     ' Step through the selected text one char at a time 
     rtbTemp.Rtf = rtb.SelectedRtf 
     For i As Integer = 0 To len - 1 
      rtbTemp.[Select](rtbTempStart + i, 1) 
      rtbTemp.SelectionFont = New Font(rtbTemp.SelectionFont.FontFamily, fontSize, rtbTemp.SelectionFont.Style) 
     Next 

     ' Replace & reselect 
     rtbTemp.[Select](rtbTempStart, len) 
     rtb.SelectedRtf = rtbTemp.SelectedRtf 
     rtb.[Select](rtb1start, len) 
     Return 
    End Sub 

Answer 1

下面是代碼： 的XAML字體大小組合框：

  <ComboBox Width="50" Name="FontsSizeCombo" FontSize="12" ItemsSource="{Binding}"> 
       <ComboBoxItem Content="8"/> 
       <ComboBoxItem Content="9" /> 
       <ComboBoxItem Content="10" /> 
       <ComboBoxItem Content="11" /> 
       <ComboBoxItem Content="12" /> 
       <ComboBoxItem Content="14" /> 
       <ComboBoxItem Content="16" /> 
       <ComboBoxItem Content="18" /> 
       <ComboBoxItem Content="22" /> 
       <ComboBoxItem Content="24" /> 
       <ComboBoxItem Content="26" /> 
       <ComboBoxItem Content="36" /> 
       <ComboBoxItem Content="48" /> 
       <ComboBoxItem Content="72" /> 
      </ComboBox> 

工作Vb.Net代碼：

Private Sub FontsSizeCombo_DropDownClosed(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FontsSizeCombo.DropDownClosed 
    mainRTB.Selection.ApplyPropertyValue(RichTextBox.FontSizeProperty, FontsSizeCombo.Text) 
End Sub 

mainRtb是我的富文本框。如果它是正確的，請檢查這個答案。謝謝。