当另一个标签在同一方向上找到时，请停止移动标签

Question

我在一个picturebox上有很多标签。我想移动的标签相对于光标，但标签上应停止移动时，有在移动方向

这里的另一个标签是我的代码

void lbl_MouseClick(object sender, MouseEventArgs e) 
    { 
     try 
     { 
      lblCutPaste = sender as Control; 
     } 
     catch (Exception err) 
     { 
      MessageBox.Show(err.Message); 
     } 
    } 

    void lbl_MouseDown(object sender, MouseEventArgs e) 
    { 
     try 
     { 
      activeControl = sender as Control; 
      previousLocation = e.Location; 
      // preloc = activeControl.Location; 
      Cursor = Cursors.Hand; 



     } 
     catch (Exception err) 
     { 
      MessageBox.Show(err.Message); 
     } 
    } 

    void lbl_MouseMove(object sender, MouseEventArgs e) 
    { 
     try 
     { 
      bool isCollide = false; 
      if (activeControl == null || activeControl != sender) 
       return; 
      var location = activeControl.Location; 
      location.Offset(e.Location.X - previousLocation.X, e.Location.Y - previousLocation.Y); 

      if (location.X >= 0 && location.X <= activeControl.Parent.Width - activeControl.Width && location.Y >= 0 && location.Y <= activeControl.Parent.Height - activeControl.Height) 
      { 
       activeControl.Location = location; 

      } 
     } 
     catch (Exception err) 
     { 
      MessageBox.Show(err.Message); 
     } 
    } 

    void lbl_MouseUp(object sender, MouseEventArgs e) 
    { 
     activeControl = null; 
     Cursor = Cursors.Default; 

    } 

Answer 1

这里是一个工作示例;学习之后，你将不得不调整你的代码。将lambda放入事件并不难。

它首先创建20 Labels并将它们添加到PictureBox。它将每个Label与三个事件挂钩。当它被拖动时，它会激活当前的Label。

每个Label也被添加到班级List<T>，所以我们可以很容易地做我们需要的检查。该检查使用LINQ来计算所有重叠标签。

它使用的Rectangle.IntersectsWith和Point.Subtract方法..

List<Label> myLabels = new List<Label>(); 
Label movingLabel = null; 
Point mDown = Point.Empty; 

private void button11_Click(object sender, EventArgs e) 
{ 
    Random R = new Random(8); 
    Size sz = pictureBox1.ClientSize; 
    for (int i = 0; i < 20; i++) 
    { 
     Label lbl = new Label() {Text = "L " + i}; 
     lbl.Location = new Point(R.Next(sz.Width), R.Next(sz.Height)); 
     lbl.Parent = pictureBox1; 
     myLabels.Add(lbl); 

     lbl.BorderStyle = BorderStyle.FixedSingle; 

     lbl.MouseDown += (ss, ee) => 
      { 
       movingLabel = lbl; 
       lbl.BackColor = Color.Bisque; 
       mDown = ee.Location; 
      }; 

     lbl.MouseMove += (ss, ee) => 
      { 
       if (ee.Button == MouseButtons.Left) 
       { 
        Point nLoc = Point.Subtract(lbl.Location, 
             new Size(mDown.X - ee.X, mDown.Y - ee.Y)); 
        Rectangle rlbNew = new Rectangle(nLoc, lbl.Size); 
        var overlapped = myLabels.Where(x => x != lbl && 
           rlbNew.IntersectsWith(new Rectangle(x.Location, x.Size))); 
        if (overlapped.Count() == 0) lbl.Location = nLoc; 
       } 
      }; 

     lbl.MouseUp += (ss, ee) => 
      { 
       movingLabel = null; 
       lbl.BackColor = Color.Transparent; 
      }; 
    } 
} 

请注意，我并不在意是否创建Labels重叠，所以一些做，因为他们不能，除非你除了感动继续拖动，直到达到“合法”的一个;那么它将跳过重叠的标签并跳转到新位置。

如果您想要编码逻辑以允许在移动时重叠，请将背景颜色设为红色以显示此操作不正常，并使其跳回MouseUp如果它仍然重叠。您需要为此存储原始位置..但拖动到合法位置，因为它可能是足够好，imo ..