我有一个文本块,我动态添加字符串。即使我添加了字符串的宽度并更新了文本块,文本块仍然没有显示适当的宽度,仍然有一些文字被截断。
如何测量要在文本块中显示的宽度?如何使其自动调整大小?
以下是关于如何获取文本大小的解决方案:
您可以使用FormattedText来测量文本的大小,以下是一个示例:
String text = "Here is my text";
Typeface myTypeface = new Typeface("Helvetica");
FormattedText ft = new FormattedText(text, CultureInfo.CurrentCulture,
FlowDirection.LeftToRight, myTypeface, 16, Brushes.Red);
Size textSize = new Size(ft.Width, ft.Height);
使用Graphics类(在这里找到):
System.Drawing.Font font = new System.Drawing.Font("Calibri", 12, FontStyle.Bold);
Bitmap bitmap = new Bitmap(1, 1);
Graphics g = Graphics.FromImage(bitmap);
SizeF measureString = g.MeasureString(text, font);
这里是你需要的内容!
没有指定高度或宽度的文本块将自动扩展,直到填满其容器。因此,请尝试这样做。
我写了一个类来实现这个功能。它只能自动缩小,但你可以添加你需要的功能。它使用父级边界或者如果设置了MaxHeight/MaxWidth,则使用它们。
public class TextBlockAutoShrink : TextBlock
{
// private Viewbox _viewBox;
private double _defaultMargin = 6;
private Typeface _typeface;
static TextBlockAutoShrink()
{
TextBlock.TextProperty.OverrideMetadata(typeof(TextBlockAutoShrink), new FrameworkPropertyMetadata(new PropertyChangedCallback(TextPropertyChanged)));
}
public TextBlockAutoShrink() : base()
{
_typeface = new Typeface(this.FontFamily, this.FontStyle, this.FontWeight, this.FontStretch, this.FontFamily);
base.DataContextChanged += new DependencyPropertyChangedEventHandler(TextBlockAutoShrink_DataContextChanged);
}
private static void TextPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
{
var t = sender as TextBlockAutoShrink;
if (t != null)
{
t.FitSize();
}
}
void TextBlockAutoShrink_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
FitSize();
}
protected override void OnRenderSizeChanged(SizeChangedInfo sizeInfo)
{
FitSize();
base.OnRenderSizeChanged(sizeInfo);
}
private void FitSize()
{
FrameworkElement parent = this.Parent as FrameworkElement;
if (parent != null)
{
var targetWidthSize = this.FontSize;
var targetHeightSize = this.FontSize;
var maxWidth = double.IsInfinity(this.MaxWidth) ? parent.ActualWidth : this.MaxWidth;
var maxHeight = double.IsInfinity(this.MaxHeight) ? parent.ActualHeight : this.MaxHeight;
if (this.ActualWidth > maxWidth)
{
targetWidthSize = (double)(this.FontSize * (maxWidth / (this.ActualWidth + _defaultMargin)));
}
if (this.ActualHeight > maxHeight)
{
var ratio = maxHeight / (this.ActualHeight);
// Normalize due to Height miscalculation. We do it step by step repeatedly until the requested height is reached. Once the fontsize is changed, this event is re-raised
// And the ActualHeight is lowered a bit more until it doesnt enter the enclosing If block.
ratio = (1 - ratio > 0.04) ? Math.Sqrt(ratio) : ratio;
targetHeightSize = (double)(this.FontSize * ratio);
}
this.FontSize = Math.Min(targetWidthSize, targetHeightSize);
}
}
}
这里提供一种解决该问题的不同方法。
设置yourTextBlock.Width = double.NaN
,同时设置Height
也是同样的方式。
默认情况下,元素具有HorizontalAligment
和VerticalAligment
属性,其设置为Stretch
,因此它们将适应其父级。
但是,如果您将这些设置为Center
,则元素将保持其自然大小,因此您可以测试此功能(或者使用代码而不是XAML设置属性):
<TextBlock Text="This is my text"
HorizontalAlignment="Center"
VerticalAlignment="Center"
/>
它在我的情况下起作用了,可能不是每种情况都适用。
MyTextBlock.TextWrapping = TextWrapping.Wrap;
我的文本块.TextWrapping = TextWrapping.Wrap;