UserControl的标签隐藏了MouseEnter事件

debugcn 发表于 Dev

塔蒂亚娜M

由于标签在顶部，因此我无法激活事件鼠标的输入。我尝试分配相同的事件，但是当我调用MyUserControl myUserControl =（MyUserControl）sender时；导致错误。这是我的代码：

foreach (Control ctrl in MyUserControl.Controls)
{
     ctrl.MouseEnter += MyUserControl_MouseEnter;
}    

private void MyUserControl_MouseEnter(object sender, EventArgs e)
{
   MyUserControl myUC = (MyUserControl)sender;
   int test = myUC .Codigo;
}

事件（Form_MouseEnter）在表单中发生时起作用，但在组件中它返回诸如'System.InvalidCastException'的错误

public partial class MyUserControl : UserControl
{
    int g_intCodEquip;
    public int Codigo
    {
        set { g_intCodEquip = value; }
        get { return g_intCodEquip; }
    }
}

IV软件

为了确保正确处理MyUserControl的所有子控件，我们可以迭代MyUserControl的控件树并订阅MouseEnter事件。

我们将所有这些事件路由到集中式Any_MouseEnter处理程序，该处理程序又触发Form1订阅的新自定义事件：

public partial class MyUserControl : UserControl
{
    public MyUserControl()
    {
        InitializeComponent();
        IterateControlTree();
    }

    void IterateControlTree(Control control = null)
    {
        if (control == null)
        {
            control = this;
        }
        control.MouseEnter += Any_MouseEnter;
        foreach (Control child in control.Controls)
        {
            IterateControlTree(child);
        }
    }

    private void Any_MouseEnter(object sender, EventArgs e)
    {
        // Before calling Invoke we need to make sure that
        // MyUserControlMouseEnter is not null as would be
        // the case if there are no subscribers to the event.
        // The '?' syntax performs this important check.
        MyUserControlMouseEnter?.Invoke(this, EventArgs.Empty);
    }

    // A custom event that this custom control can fire.
    public event EventHandler MyUserControlMouseEnter;

    public int Codigo
    {
        set
        {
            test = value;
        }
        get
        {
            return test;
        }
    }
    int test = 0;
}

注意：这是您上一篇文章的后续问题，因此我在“ Codigo”属性上进行了复制。

好，现在在主Form1中，我们订阅MyUserControl触发的新事件。现在，发送者的类型为MyUserControl，强制转换成功，并且无论鼠标进入哪个控件，通知都有效。

private void MyUserControl_MouseEnter(object sender, EventArgs e)
{
    MyUserControl myUserControl = (MyUserControl)sender;
    Debug.WriteLine(
        "MouseEnter Detected: " + myUserControl.Name + 
        " - Value of Codigo is: " + myUserControl.Codigo);
}

作为测试跑步者，我们可以设置4 x 3的MyUserControl数组（工作示例MyUserControl包含一个Label和一个Button）。

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    TableLayoutPanel tableLayoutPanel1 = new TableLayoutPanel() { ColumnCount = 4, RowCount = 4, Dock = DockStyle.Fill };
    protected override void OnHandleCreated(EventArgs e)
    {
        base.OnHandleCreated(e);
        Controls.Add(tableLayoutPanel1);
        int row, column;
        for (int count = 0; count < 12; count++)
        {
            row = count / 4; column = count % 4;

            MyUserControl myUserControl = new MyUserControl();
            myUserControl.Name = "MyUserControl_" + count.ToString("D2"); // Name it! (Default is "") 

            // vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv  
            // Subscribe to custom event fired by MyUserControl             
            myUserControl.MyUserControlMouseEnter += MyUserControl_MouseEnter;
            // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^        

            myUserControl.Codigo = 1000 + count;                         // Example to set Codigo

            tableLayoutPanel1.Controls.Add(myUserControl, column, row);
        }
    }
}

该行为遵循此10秒剪辑。

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