如果在进入控件时 MouseButton 按下，C# 如何触发 MouseMove 或 MouseEnter 事件？

Question

我需要在鼠标左键按下时触发 MouseMove 或 MouseEnter 事件。不幸的是，当鼠标左键按下时，这些事件不会被触发。

我已经尝试过此线程中的解决方案： C# triggering MouseEnter even even if mouse button is held down

但它不起作用，因为它只对窗体起作用，对控件不起作用。这个想法很简单，假设我有 10 个标签并排放置。在我在一个标签上按下鼠标后 --> 它的背景颜色变为红色，然后我按住 MouseLeftButton 并继续将鼠标移动到其他标签，我希望这些标签的背景色也变为红色，而无需松开鼠标任何一点。

我尝试使用一个布尔变量来存储鼠标按钮的状态，在 MouseDown 事件中 --> MouseDown = true; 然后在 MouseEnter 或 MouseMove 处使用该布尔值，但根本不会触发这些事件。谢谢大家

Answer 1

必须在MouseDown事件中使用Label.Capture = false;表示此事件允许其他事件运行。

完整代码我放上

public partial class Form1 : Form
{
   bool Ispressed = false; 
   public Form1()
   {
      InitializeComponent();
      for(int i=1; i<=10;i++)
      {
          Label lbl = new Label();
          lbl.Name = "lbl" + i;
          lbl.Text = "Label " + i;
          lbl.Location = new System.Drawing.Point(150, i * 40);
          lbl.MouseDown += new MouseEventHandler(Lbl_MouseDown);
          lbl.MouseUp += new MouseEventHandler(Lbl_MouseUp);
          lbl.MouseMove += new MouseEventHandler(Lbl_MouseMove);
          lbl.MouseLeave += new System.EventHandler(Lbl_MouseLeave);
          this.Controls.Add(lbl);
      }
   }
   private void Lbl_MouseMove(object sender, MouseEventArgs e)
   {
      if (Ispressed)
      {
          Label lbl = sender as Label;
          lbl.BackColor = Color.Red;
      }
   }

   private void Lbl_MouseLeave(object sender, EventArgs e)
   {
      Label lbl = sender as Label;
      lbl.BackColor = Color.Transparent;
   }       
   private void Lbl_MouseDown(object sender, MouseEventArgs e)
   {
      Label lbl = sender as Label;
      lbl.BackColor = Color.Red;

      lbl.Capture = false;
      Ispressed = true;
   }
   private void Lbl_MouseUp(object sender, MouseEventArgs e)
   {
       Ispressed = false;
       foreach(Control ctr in this.Controls)
       {
          if(ctr is Label)
          {
             ctr.BackColor = Color.Transparent;
          }
       }
   }
 }

如果在进入控件时 MouseButton 按下，C# 如何触发 MouseMove 或 MouseEnter 事件？

C# how to trigger MouseMove or MouseEnter events if MouseButton is down when entering a control?

c#

eventtrigger