Question

我正在尝试构建简单的应用程序，它围绕某个枢轴旋转机器人手臂。但我的结果真的很奇怪。我该怎么做才能改变它以给出正确的价值？我的意思是现在它漂浮在一些我无法识别的奇怪点上，但我已经提供了它应该旋转哪个点的信息。 PS。对不起这段代码中的“乱七八糟”，最终版本会更好。但如果我不能继续简单的草图我怎么能前进：
的 XAML：

<DockPanel>
    <Grid DockPanel.Dock="Top">
      <Border>
        <Canvas Name="plotno" RenderTransformOrigin="0,0" Width="856" Height="520">
          <Slider x:Name="slider1" Canvas.Left="631" Canvas.Top="100" Height="21" Width="198" ValueChanged="slider1_ValueChanged" TickPlacement="Both" SmallChange="1" Maximum="360"/>
        </Canvas>
      </Border>
    </Grid>
  </DockPanel>

C＃

public partial class MainWindow : Window
      {
      public MainWindow()
      {
      InitializeComponent();
      }
      Line myLine = new Line();
      Line myLine2 = new Line();
      long centerheight;
      long centerwidth;
      private void Window_Loaded(object sender, RoutedEventArgs e)
      {

      myLine.Stroke = Brushes.LightSteelBlue;
      centerwidth = Convert.ToInt64(plotno.Width / 2);
      centerheight = Convert.ToInt64(plotno.Height / 2);
      myLine.X1 = centerwidth;
      myLine.X2 = myLine.X1+100;
      myLine.Y1 = centerheight;
      myLine.Y2 = myLine.Y1 + 100;
      myLine.StrokeThickness = 10;
      plotno.Children.Add(myLine);
      //rotate by a degree
      myLine.RenderTransformOrigin = new Point(myLine.X1, myLine.Y1);
      //RotateTransform r = new RotateTransform(0);
      //myLine.RenderTransform = r;
      //this should stick my second line to first one but first one disappears
      var newP1 = myLine.RenderTransform.Transform(new Point(myLine.X2, myLine.Y2));
      myLine2.X1 = newP1.X;
      myLine2.Y1 = newP1.Y;
      myLine2.X2 = myLine2.X1+100;
      myLine2.Y2 = myLine2.Y1 + 100;
      System.Diagnostics.Debug.WriteLine(myLine.X1);
      System.Diagnostics.Debug.WriteLine(myLine.Y1);
      System.Diagnostics.Debug.WriteLine(myLine.X2);
      System.Diagnostics.Debug.WriteLine(myLine.Y2);
      myLine2.Stroke = Brushes.Red;
      myLine2.StrokeThickness = 10;
      Line whereshouldbeminerotationpivot = new Line();
      whereshouldbeminerotationpivot.X1 = myLine.RenderTransformOrigin.X;
      whereshouldbeminerotationpivot.X2 = myLine.RenderTransformOrigin.X + 10;
      whereshouldbeminerotationpivot.Y1 = myLine.RenderTransformOrigin.Y;
      whereshouldbeminerotationpivot.Y2 = myLine.RenderTransformOrigin.Y + 10;
      whereshouldbeminerotationpivot.Stroke = Brushes.Red;
      whereshouldbeminerotationpivot.StrokeThickness = 20;

      plotno.Children.Add(whereshouldbeminerotationpivot);
      plotno.Children.Add(myLine2);

    }

    private void slider1_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
    {
      var linie = plotno.Children.OfType<Line>().ToList();
      foreach (var linia in linie)
      {
        plotno.Children.Remove(linia);
      }
      for (int i = 0; i < plotno.Children.Capacity; i++)
      { System.Diagnostics.Debug.WriteLine(plotno.Children.Count); }

      myLine.X1 = centerwidth;
      myLine.X2 = myLine.X1+100;
      myLine.Y1 = centerheight;
      myLine.Y2 = myLine.Y1 + 100;
myLine.Stroke = Brushes.LightSteelBlue;
      myLine.StrokeThickness = 10;
      plotno.Children.Add(myLine);
      //myLine.LayoutTransform = new RotateTransform(30,0.5,0.5);
      //rotate by a degree
      myLine.RenderTransformOrigin = new Point(myLine.X1, myLine.Y1);
      RotateTransform r = new RotateTransform(e.NewValue);
      myLine.RenderTransform = r;
      //this should stick my second line to first one but first one disappears
      var newP1 = myLine.RenderTransform.Transform(new Point(myLine.X2, myLine.Y2));
      myLine2.X1 = newP1.X;
      myLine2.Y1 = newP1.Y;
      myLine2.X2 = newP1.X+100;
      myLine2.Y2 = newP1.Y+100;
      System.Diagnostics.Debug.WriteLine(myLine.X1);
      System.Diagnostics.Debug.WriteLine(myLine.Y1);
      System.Diagnostics.Debug.WriteLine(myLine.X2);
      System.Diagnostics.Debug.WriteLine(myLine.Y2);
      myLine2.Stroke = Brushes.Gray;
      myLine2.StrokeThickness = 10;
      Line whereshouldbeminerotationpivot=new Line();
      whereshouldbeminerotationpivot.X1 = myLine.RenderTransformOrigin.X;
      whereshouldbeminerotationpivot.X2 = myLine.RenderTransformOrigin.X+10;
      whereshouldbeminerotationpivot.Y1 = myLine.RenderTransformOrigin.Y;
      whereshouldbeminerotationpivot.Y2 = myLine.RenderTransformOrigin.Y+10;
whereshouldbeminerotationpivot.Stroke = Brushes.Red;
      whereshouldbeminerotationpivot.StrokeThickness = 20;

      plotno.Children.Add(whereshouldbeminerotationpivot);
      plotno.Children.Add(myLine2);
    }

  }

Answer 1

正如我之前在评论中提到的那样 - 我只是脑力激荡并忘记了我必须实际使用RotateTransform对象的重载构造函数。它看起来像这样：

Line 93 RotateTransform r = new RotateTransform(e.NewValue, centerwidth,centerheight);

但是，尽管它正确旋转（在线的一端附近），当第二个与第一个重叠时，线消失。谁知道为什么？我尝试改变添加（可视化）儿童的顺序，但它不起作用。我只有第一行的问题。我在画布中间的标记和第二行总是可以正确显示

绕某些枢轴旋转线的问题

1 个答案: