我有 WritableBitmap 图像，我已经在图像控件 src 中设置了。当用户在选定的文本区域上移动时，我正在创建矩形。我还使用 PDFtron SDK 从 PDF 文档中获取选定的文本。 我们从 PDF 中获取 WritableBitmap 图像。我们必须在线选择文本。

我正在使用这段代码绘制屏幕:

System.Drawing.Rectangle rectangle = new System.Drawing.Rectangle((int)Math.Min(_downX, x),
                             (int)Math.Min(_downY, y),
                             (int)Math.Abs(_downX - x),
                             (int)Math.Abs(_downY - y));

System.Drawing.Bitmap myBitmap = new System.Drawing.Bitmap(@"D:\PDF\ScreenDraw\WpfApplication1\WpfApplication1\Image\Capture.PNG");

using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(myBitmap))
{
    System.Drawing.Color customColor = System.Drawing.Color.FromArgb(50, System.Drawing.Color.Red);
    System.Drawing.SolidBrush shadowBrush = new System.Drawing.SolidBrush(customColor);
    g.FillRectangles(shadowBrush, new System.Drawing.Rectangle[] { rectangle });
}

//myBitmap.Save(@"D:\PDF\abc.png");
//bitmapSource = new BitmapImage(new Uri(@"D:\PDF\abc.png", UriKind.Absolute));

using (var memory = new System.IO.MemoryStream())
{
    myBitmap.Save(memory, System.Drawing.Imaging.ImageFormat.Png);
    memory.Position = 0;

    var bitmapImage = new BitmapImage();
    bitmapImage.BeginInit();
    bitmapImage.StreamSource = memory;
    bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
    bitmapImage.EndInit();
    Img.Source = bitmapImage;
}

我如何选择线而不是 Rect 的文本？

我必须选择如上图所示的文本。

最佳答案

你想要的是不可能的。你有一个位图，它并没有神奇地意识到其中的文本，并且没有任何改变。 虽然并不是说你无能为力。 我没有时间提供完整的解决方案，但我可以提供有关如何实现最佳解决方案的分步说明。

你可以做的是:

1. 文本尺寸定义 - 创建带有覆盖在图像上的网格的控件，具有可编辑的 X 轴和 Y 轴步长和偏移量。然后您将能够使用文本行 (Y) 校准网格。和字符宽度 (X)。 应该做这样的事情(我想你会明白一般的想法):

   public int XGridStep
   {
       get { return (int)base.GetValue(XGridStepProperty); }
       set
       {
           base.SetValue(XGridStepProperty, value);
           RepaintGrid();
       }
   }
   
   public static readonly DependencyProperty XGridStepProperty = DependencyProperty.Register("XGridStepProperty", typeof(int), typeof(PlanLayout), new PropertyMetadata(100));
   
   public int XGridOffset
   {
       get { return (int)base.GetValue(XGridOffsetProperty); }
       set
       {
           base.SetValue(XGridOffsetProperty, value);
           RepaintGrid();
       }
   }
   
   public static readonly DependencyProperty XGridOffsetProperty = DependencyProperty.Register("XGridOffsetProperty", typeof(int), typeof(PlanLayout), new PropertyMetadata(0));
   
   public bool XGridVisible
   {
       get { return (bool)base.GetValue(XGridVisibleProperty); }
       set
       {
           base.SetValue(XGridVisibleProperty, value);
           RepaintGrid();
       }
   }
   
   public static readonly DependencyProperty XGridVisibleProperty = DependencyProperty.Register("XGridVisibleProperty", typeof(bool), typeof(PlanLayout), new PropertyMetadata(false));
   
   public int YGridStep
   {
       get { return (int)base.GetValue(YGridStepProperty); }
       set
       {
           base.SetValue(YGridStepProperty, value);
           RepaintGrid();
       }
   }
   
   public static readonly DependencyProperty YGridStepProperty = DependencyProperty.Register("YGridStepProperty", typeof(int), typeof(PlanLayout), new PropertyMetadata(100));
   
   public int YGridOffset
   {
       get { return (int)base.GetValue(YGridOffsetProperty); }
       set
       {
           base.SetValue(YGridOffsetProperty, value);
           RepaintGrid();
       }
   }
   
   public static readonly DependencyProperty YGridOffsetProperty = DependencyProperty.Register("YGridOffsetProperty", typeof(int), typeof(PlanLayout), new PropertyMetadata(0));
   
   public bool YGridVisible
   {
       get { return (bool)base.GetValue(YGridVisibleProperty); }
       set
       {
           base.SetValue(YGridVisibleProperty, value);
           RepaintGrid();
       }
   }
   
   public static readonly DependencyProperty YGridVisibleProperty = DependencyProperty.Register("YGridVisibleProperty", typeof(bool), typeof(PlanLayout), new PropertyMetadata(false));
   
   private void RepaintGrid()
   {
       if (!IsEditable)
           return;
   
       foreach (Line l in _gridXLines)
           content.Children.Remove(l);
       _gridXLines.Clear();
       if (XGridVisible)
           for (int i = XGridOffset; i < content.ActualWidth; i += XGridStep)
           {
               Line line = new Line();
               line.IsHitTestVisible = false;
               line.Stroke = Brushes.Black;
               line.Y1 = 0;
               line.Y2 = content.ActualHeight;
               line.X1 = line.X2 = i;
               if (Math.Abs(line.X1 - content.ActualWidth) < XGridStep * 0.5 || line.X1 < XGridStep * 0.5)
                   continue;
               _gridXLines.Add(line);
               content.Children.Add(line);
               Canvas.SetZIndex(line, 0);
           }
   
       foreach (Line l in _gridYLines)
           content.Children.Remove(l);
       _gridYLines.Clear();
       if (YGridVisible)
           for (int i = YGridOffset; i < content.ActualHeight; i += YGridStep)
           {
               Line line = new Line();
               line.IsHitTestVisible = false;
               line.Stroke = Brushes.Black;
               line.X1 = 0;
               line.X2 = content.ActualWidth;
               line.Y1 = line.Y2 = i;
               if (Math.Abs(line.Y1 - content.ActualHeight) < YGridStep * 0.5 || line.Y1 < YGridStep * 0.5)
                   continue;
               _gridYLines.Add(line);
               content.Children.Add(line);
               Canvas.SetZIndex(line, 0);
           }
   }
   

2. 文本选择 - 您现在要做的就是向您的控件添加“对齐网格”功能。同样，仅供引用:

   private void elementWrapper_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
   {
       if (_mouseHandlingMode != MouseHandlingMode.Dragging)
           return;
   
       SelectableElement element = (SelectableElement)sender;
   
       Point curContentPoint = e.GetPosition(content);
       //Vector elementDragVector = curContentPoint - _origContentMouseDownPoint;
   
       _origContentMouseDownPoint = curContentPoint;
   
       //double destinationLeft = Canvas.GetLeft(element) + elementDragVector.X;
       //double destinationTop = Canvas.GetTop(element) + elementDragVector.Y;
       double destinationLeft = curContentPoint.X - element.ActualWidth / 2;
       double destinationTop = curContentPoint.Y - element.ActualHeight / 2;
   
       if (SnapToGrid)
       {
           if (XGridVisible)
           {
               foreach (Line l in _gridXLines)
                   l.StrokeThickness = 1;
   
               Line nearest = GetNearestXGridLine((int)curContentPoint.X);
   
               if (Math.Abs(curContentPoint.X - nearest.X1) < XGridStep * 0.2)
               {
                   destinationLeft = nearest.X1 - element.ActualWidth / 2;
                   nearest.StrokeThickness = 3;
               }
           }
   
           if (YGridVisible)
           {
               foreach (Line l in _gridYLines)
                   l.StrokeThickness = 1;
   
               Line nearest = GetNearestYGridLine((int)curContentPoint.Y);
   
               if (Math.Abs(curContentPoint.Y - nearest.Y1) < YGridStep * 0.2)
               {
                   destinationTop = nearest.Y1 - element.ActualHeight / 2;
                   nearest.StrokeThickness = 3;
               }
           }
       }
   
       if (destinationLeft < 0)
           destinationLeft = 0;
   
       if (destinationLeft > content.ActualWidth - element.ActualWidth)
           destinationLeft = content.ActualWidth - element.ActualWidth;
   
       if (destinationTop < 0)
           destinationTop = 0;
   
       if (destinationTop > content.ActualHeight - element.ActualHeight)
           destinationTop = content.ActualHeight - element.ActualHeight;
   
       Canvas.SetLeft(element, destinationLeft);
       Canvas.SetTop(element, destinationTop);
   
       element.ElementContent.Position.X = curContentPoint.X;
       element.ElementContent.Position.Y = curContentPoint.Y;
   
       e.Handled = true;
   }
   
   private Line GetNearestXGridLine(int xpos)
   {
       return _gridXLines.OrderBy(gl => Math.Abs((int)gl.X1 - xpos)).First();
   }
   
   private Line GetNearestYGridLine(int Ypos)
   {
       return _gridYLines.OrderBy(gl => Math.Abs((int)gl.Y1 - Ypos)).First();
   }
   

3. 选择的图形表示 - 现在绘制(最多)3 个矩形:从选择的左上点到相关文本行的右下点，下一行的左上点到最后选择的前一行的右下点和最后一行的左上点到选择的右下角

4. 获取文本 - 从这些矩形中获取部分文本数据并加入。

关于c# - 如何在 wpf c# 中的 WritableBitmap 中选择或突出显示鼠标移动事件中的文本，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31579033/