WPF 文本块部分高亮突出显示

WPF 文本块部分高亮突出显示

实现思路

• 利用TextBlock可以使用Run来组成Text内容的特性实现。

  public class HighlightTextblock : TextBlock
    {
        public string DefaultText { get; set; }

        public string HiText
        {
            get { return (string)GetValue(HiTextProperty); }
            set { SetValue(HiTextProperty, value); }
        }

        // Using a DependencyProperty as the backing store for HiText.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty HiTextProperty =
            DependencyProperty.Register("HiText", typeof(string), typeof(HighlightTextblock), new PropertyMetadata(string.Empty, OnHiTextChanged));

        private static void OnHiTextChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            HighlightTextblock block = d as HighlightTextblock;
            block.UpdateHighText(e.NewValue.ToString());
        }

        private void UpdateHighText(string hiText)
        {
            if (string.IsNullOrEmpty(DefaultText) || DefaultText != Text)
            {
                DefaultText = Text;
            }

            if (!string.IsNullOrEmpty(hiText))
            {
                Text = string.Empty;

                string[] spli = Regex.Split(DefaultText, hiText, RegexOptions.IgnoreCase);
                for (int i = 0; i < spli.Length; i++)
                {
                    Inlines.Add(new Run(spli[i]));

                    if (i < spli.Length - 1)
                    {
                        int searchstart = Text.Length;
                        var iCaseTextIndex = DefaultText.IndexOf(hiText, searchstart, StringComparison.OrdinalIgnoreCase);
                        if (iCaseTextIndex < 0)
                        {
                            continue;
                        }
                        string caseText = DefaultText.Substring(iCaseTextIndex, hiText.Length);
                        Inlines.Add(new Run(caseText) { Background = Brushes.Yellow });
                    }
                }
            }
            else
            {
                Text = DefaultText;
            }
        }
    }

使用代码

  <local:HighlightTextblock Text="basguabdgadsofas" HiText="{Binding ElementName=Hi, Path=Text}"/>
            <TextBox x:Name="Hi" Height="30"/>