Question

我想使用组合框更改为richtextbox中的字体大小，如果我们在选择文本中使用此代码有一种字体，则可以轻松更改字体大小。

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

但是如果我们的选择中有多种字体，它就不起作用了。我有另一个代码来解决这个问题。但是这个代码的唯一问题是它不仅仅是2000个字符，但是当选择文本很大时它就没用了。代码如下。任何帮助...

 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

这是代码：用于字体大小组合框的Xaml：

            <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代码：

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。如果正确，请将此作为答案进行检查。谢谢。

在richtextbox中为vb.net中的多种字体设置字体大小

1 个答案: