c# – TextBlock,其中一些文本左对齐,其余文本右对齐

>填写空格以给出对齐的外观.
>使用InlineUIContainer在TextBlock中添加实际的UI元素(可以对齐).

我将通过创建具有LeftAlignedText和RightAlignedText属性的ExtendedTextBlock控件给出每个示例.用法是这样的：

<my:ExtendedTextBlock RightAlignedText=":" LeftAlignedText="My associated textbox is" />

1)用空格填充.

对于这种方法,我从this answer借来获得文本字符串的实际宽度.这个想法基本上是从控件的实际宽度中减去文本的总宽度,并在它们之间插入适当数量的空格.

public class ExtendedTextBlock : TextBlock
{
    public string RightAlignedText
    {
        get { return (string)GetValue(RightAlignedTextProperty); }
        set { SetValue(RightAlignedTextProperty,value); }
    }
    public static readonly DependencyProperty RightAlignedTextProperty =
        DependencyProperty.Register("RightAlignedText",typeof(string),typeof(ExtendedTextBlock),new PropertyMetadata(SetText));

    public string LeftAlignedText
    {
        get { return (string)GetValue(LeftAlignedTextProperty); }
        set { SetValue(LeftAlignedTextProperty,value); }
    }
    public static readonly DependencyProperty LeftAlignedTextProperty =
        DependencyProperty.Register("LeftAlignedText",new PropertyMetadata(SetText));

    public static void SetText(object sender,DependencyPropertyChangedEventArgs args)
    {
        SetText((ExtendedTextBlock)sender);
    }

    public static void SetText(ExtendedTextBlock owner)
    {
        if (owner.ActualWidth == 0)
            return;

        // helper function to get the width of a text string
        Func<string,double> getTextWidth = text =>
        {
            var formattedText = new FormattedText(text,CultureInfo.CurrentUICulture,FlowDirection.LeftToRight,new Typeface(owner.FontFamily,owner.FontStyle,owner.FontWeight,owner.FontStretch),owner.FontSize,Brushes.Black);
            return formattedText.Width;
        };

        // calculate the space needed to fill in
        double spaceNeeded = owner.ActualWidth - getTextWidth(owner.LeftAlignedText ?? "") - getTextWidth(owner.RightAlignedText ?? "");

        // get the width of an empty space (have to cheat a bit since the width of an empty space returns zero)
        double spaceWidth = getTextWidth(" .") - getTextWidth(".");
        int spaces = (int)Math.Round(spaceNeeded / spaceWidth);

        owner.Text = owner.LeftAlignedText + new string(Enumerable.Repeat(' ',spaces).ToArray()) + owner.RightAlignedText;
    }

    public ExtendedTextBlock()
    {
        SizeChanged += (sender,args) => SetText(this);
    }
}

2)使用InlineUIContainer添加对齐的文本

这里的想法是在TextBlock中添加一个面板,它将负责对齐每个文本字符串.这是基本的想法：

<TextBlock>
    <InlineUIContainer>
        <Grid Width="{Binding RelativeSource={RelativeSource AncestorType=TextBlock},Path=ActualWidth}">
            <TextBlock Text="Hello" />
            <TextBlock Text="World" TextAlignment="Right" />
        </Grid>
    </InlineUIContainer>
</TextBlock>

因此,此版本的控件重新创建上述内容但隐藏了实现.它将InlineUIContainer控件添加到基本TextBlock,并保持对“左”和“右”TextBlocks的引用,根据需要设置其文本.

public class ExtendedTextBlock2 : TextBlock
{
    private TextBlock _left,_right;

    public string RightAlignedText
    {
        get { return (string)GetValue(RightAlignedTextProperty); }
        set { SetValue(RightAlignedTextProperty,typeof(ExtendedTextBlock2),new PropertyMetadata(SetText));

            public static void SetText(object sender,DependencyPropertyChangedEventArgs args)
    {
        ((ExtendedTextBlock2)sender).SetText();
    }

    public void SetText()
    {
        if (_left == null || _right == null)
            return;
        _left.Text = LeftAlignedText;
        _right.Text = RightAlignedText;
    }

    public ExtendedTextBlock2()
    {
        Loaded += ExtendedTextBlock2_Loaded;
    }

    void ExtendedTextBlock2_Loaded(object sender,RoutedEventArgs e)
    {
        Inlines.Clear();
        var child = new InlineUIContainer();
        var container = new Grid();
        var widthBinding = new Binding { Source = this,Path = new PropertyPath(TextBlock.ActualWidthProperty) };
        container.SetBinding(Grid.WidthProperty,widthBinding);
        child.Child = container;
        container.Children.Add(_left = new TextBlock { HorizontalAlignment = System.Windows.HorizontalAlignment.Left });
        container.Children.Add(_right = new TextBlock { HorizontalAlignment = System.Windows.HorizontalAlignment.Right });
        Inlines.Add(child);

        SetText();
    }
}