WPF,richtextbox highlight text

Question

I save the information on the location of the sort algorithm changes into an array.

if (sorting[j] > sorting[j + 1])
{
      Swap(sorting, j, j + 1);

      SortingTraceInfo sortInfo = new SortingTraceInfo(); // struct Variable
      sortInfo.Position = j;  // change position save
      sortInfo.TargetPosition = j + 1;    // changed position save
      sortInfo.SortingNumbers = sorting.ToArray();    // 
      sortingInfos.Add(sortInfo);     
}

I know the index of the changed position. And it outputs the result was the richtextbox.

It applied the index(sortInfo.position) that was saved in the result(in richtextbox).

result in richtextbox. It is applied to the index. The result I want is

Output one line and color changes each time you click the button.

23 59 59 70 12 92 19 14 77 51 -> 70 < color red, 12 color blue

index ( position = 3, tartgetposition = 4),

23 59 59 12 70 92 19 14 77 51 -> 92 < color red, 19 color blue

index ( position = 5, tartgetposition = 6),

23 59 59 12 70 19 92 14 77 51 -> 92 < color red, 14 color blue

index ( position = 6, tartgetposition = 7),

However, I failed........

Answer 1

If i understood you properly, your problem is how to render texts in a RichTextBox with different Colors ! To do that you could use a TextRange for each Array item and apply brush color based on the item situation (Position -> Red, TargetPosition -> Blue, others -> Black), so for the following RichTextBox:

<StackPanel>
    <RichTextBox Name="Output">
    </RichTextBox>
    <Button Content="Next" Click="Next_OnClick"/>
</StackPanel>

you need at each Next's Button Click :

• Clear the Output RichTetex
• Iterate through the Sorting Array, and create a TextRang based on the item index

• A loop break operation should be executed each time a swap operation occurred to properly visualize the output

  public struct SortingTraceInfo
  {
    public int Position;
    public int TargetPosition;
    public int[] SortingNumbers;
  }
  
  public int[] Sorting = new[] { 23, 59, 59, 70, 12, 92, 19, 14, 77, 51 };        
  public List<SortingTraceInfo> SortingInfos=new List<SortingTraceInfo>();
  
  private void Next_OnClick(object sender, RoutedEventArgs e)
  {            
      Output.Document.Blocks.Clear();
      for (int j = 0; j < Sorting.Count()-1; j++)
      {
          if (Sorting[j] > Sorting[j + 1])
          {                   
              //render to RTB
              for (int i = 0; i < Sorting.Count(); i++)
              {
                  if (i==j)
                  {
                      //render the number red 
                      var textRange = new TextRange(Output.Document.ContentEnd, Output.Document.ContentEnd);
                      textRange.Text = Sorting[i] + " ";
                      textRange.ApplyPropertyValue(TextElement.ForegroundProperty, Brushes.Red);                            
                  }
                  else if(i==j+1)
                  {
                      //render the number blue 
                      var textRange = new TextRange(Output.Document.ContentEnd, Output.Document.ContentEnd);
                      textRange.Text = Sorting[i]+ " ";
                      textRange.ApplyPropertyValue(TextElement.ForegroundProperty, Brushes.Blue); 
  
                  }
                  else
                  {
                      //render the number black 
                      var textRange = new TextRange(Output.Document.ContentEnd, Output.Document.ContentEnd);
                      textRange.Text = Sorting[i] + " ";
                      textRange.ApplyPropertyValue(TextElement.ForegroundProperty, Brushes.Black);                             
                  }
              }
  
  
              //Swap(Sorting, j, j + 1);
              int tmp=Sorting[j];
              Sorting[j] = Sorting[j+1];
              Sorting[j + 1] = tmp;
  
              var sortInfo = new SortingTraceInfo(); // struct Variable
              sortInfo.Position = j; // change position save
              sortInfo.TargetPosition = j + 1; // changed position save
              sortInfo.SortingNumbers = Sorting.ToArray(); // 
              SortingInfos.Add(sortInfo);
  
              //handle one sorting operation one at a time 
              break;
          }               
      }           
  }
  

the result :

etc...