Question

我想用图像渲染地图。（不使用Map API）

所以我使用React-leaflet的ImageOverlay。

但是这使ImageOverlay的高度固定。

我认为图像的高度和宽度带有“ bounds”属性。

void __fastcall Tviewer_ui::viewerPageMouseMove(TObject *Sender, TShiftState Shift, int X, int Y)
{
  if (_selecting)
  {
    TColor to_color = 0;
    TColor from_color = 0; 
    Tviewer_page* vp = static_cast<Tviewer_page *>(Sender);
    Tsel_data* sel_data = &vp->_sel_datas[vp->_c_sel];

    // Scroll window if needed
    int sb_pos = _scrollBox->VertScrollBar->Position;
    if (Y > sb_pos - vp->_top + _scrollBox->Height - 10)
      _scrollBox->VertScrollBar->Position += 10;
    else 
      if (Y < sb_pos - vp->_top + 10)
        _scrollBox->VertScrollBar->Position -= 10;

    int y1 = 0;
    int y2 = 0;
    if (Y > sel_data->_start_y)
    {
      if (Y > sel_data->_last_y)
      {
        y1 = sel_data->_last_y;
        y2 = Y;
        from_color = clWhite;
        to_color = clHighlight;
      }
      else if (Y < sel_data->_last_y)
      {
        y1 = Y;
        y2 = sel_data->_last_y;
        from_color = clHighlight;
        to_color = clWhite;
      }
      sel_data->_rect.Bottom = Y;
    }
    else if (Y < sel_data->_start_y)
    {
      if (Y < sel_data->_last_y)
      {
        y1 = Y;
        y2 = sel_data->_last_y;
        from_color = clWhite;
        to_color = clHighlight;
      }
      else if (Y > sel_data->_last_y)
      {
        y1 = sel_data->_last_y;
        y2 = Y;
        from_color = clHighlight;
        to_color = clWhite;
      }
      sel_data->_rect.Top = Y;
    }
    int height = abs(y1 - y2);
    if (height > 0)
    {
      TRect srect = Rect(sel_data->_rect.Left, y1, sel_data->_rect.Right, y2);
      int width = srect.Width();
      TRect drect = Rect(sel_data->_rect.Left,0,sel_data->_rect.Right, height);
      Graphics::TBitmap* bm1 = new Graphics::TBitmap;
      bm1->Width = width;
      bm1->Height = height;
      Graphics::TBitmap* bm2 = new Graphics::TBitmap;
      bm2->Width = width;
      bm2->Height = height;

      bm1->Canvas->CopyRect(drect, vp->Canvas, srect);
      bm2->Canvas->Brush->Color = to_color;
      bm2->Canvas->BrushCopy(drect, bm1, drect, from_color);

      BitBlt(vp->Canvas->Handle, srect.Left, srect.Top, width, height, bm2->Canvas->Handle, 0, 0, SRCCOPY);  
      vp->Refresh();
      delete bm1;
      delete bm2;
    } 
    sel_data->_last_y = Y;
  }
}

这是代码。这就是图片。

然后，我将范围更改为100，

最后，我将范围更改为300

出了什么问题？？然后，标记的位置是[90,200]

React-leaflet ImageOverlay不会使父级高100％

0 个答案: