无法在 Winform C# 中捕获 Label_Mouse 事件

Question

我有 2 个标签；我想捕捉标签来改变这个标签的文本。

你可以很容易地看到这个 gif。

这个 gif 图像创建了 2 个标签，但我只更改了第一个标签的文本。无法更改第二个标签的文本。

我认为问题是 SelectedControl 无法检测到控件被选中。

我的代码无论如何MouseDown，MouseMove，....

private void control_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        panel2.Invalidate(); //unselect other control
        SelectedControl = (Control) sender;
        Control control = (Control) sender;
        mouseX = -e.X;
        mouseY = -e.Y;
        control.Invalidate();
        DrawControlBorder(sender);
        propertyGrid1.SelectedObject = SelectedControl;
        control.TextChanged += new System.EventHandler(this.txtIDImg_TextChanged);
    }
}

这将在单击按钮添加新标签 (btnAddCharacter) 时创建新标签。

private Label SelectedLabel;
List<Label> activeLabels = new List<Label>();
public bool btnAddCharacterClick = false;
public List<String> lstLabelName = new List<string>();
public void btnAddCharacter_Click(object sender, EventArgs e)
{
    txtIDImg.Focus();
    SelectedLabel = new Label();
    Random rnd = new Random();
    int randNumber = rnd.Next(1, 1000);
    String LableName = "Lbl_" + activeLabels.Count();
    panel2.Invalidate(); //unselect other control
    SelectedControl = SelectedLabel;
    SelectedLabel.Invalidate();
    DrawControlBorder(SelectedLabel);
    SelectedLabel.Name = LableName;
    SelectedLabel.AutoSize = true;
    SelectedLabel.Text = txtIDImg.Text;
    SelectedLabel.BackColor = Color.Transparent;
    SelectedLabel.MouseEnter += new EventHandler(control_MouseEnter);
    SelectedLabel.MouseLeave += new EventHandler(control_MouseLeave);
    SelectedLabel.MouseDown += new MouseEventHandler(control_MouseDown);
    SelectedLabel.MouseMove += new MouseEventHandler(control_MouseMove);
    SelectedLabel.MouseUp += new MouseEventHandler(control_MouseUp);
    panel2.Controls.Add(SelectedLabel);
    activeLabels.Add(SelectedLabel);
    lstLabelName.Add(SelectedLabel.ToString());
    btnSave.Enabled = true;
    btnDelete.Enabled = true;
    btnDeleteAll.Enabled = true;
    btnAddCharacterClick = true;
    txtIDImg.Text = "";
}

Point postPoint;
private void control_MouseMove(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        postPoint = new Point();
        Control control = (Control) sender;
        Point nextPosition = new Point();
        nextPosition = panel2.PointToClient(MousePosition);
        nextPosition.Offset(mouseX, mouseY);
        control.Location = nextPosition;
        postPoint = nextPosition;        
        Invalidate();
    }
}

private void DrawControlBorder(object sender)
{
    Control control = (Control) sender;
    Rectangle Border = new Rectangle(
        new Point(control.Location.X - DRAG_HANDLE_SIZE/2,
            control.Location.Y - DRAG_HANDLE_SIZE/2),
        new Size(control.Size.Width + DRAG_HANDLE_SIZE,
            control.Size.Height + DRAG_HANDLE_SIZE));
    Rectangle NW = new Rectangle(
        new Point(control.Location.X - DRAG_HANDLE_SIZE,
            control.Location.Y - DRAG_HANDLE_SIZE),
        new Size(DRAG_HANDLE_SIZE, DRAG_HANDLE_SIZE));
    Rectangle N = new Rectangle(
        new Point(control.Location.X + control.Width/2 - DRAG_HANDLE_SIZE/2,
            control.Location.Y - DRAG_HANDLE_SIZE),
        new Size(DRAG_HANDLE_SIZE, DRAG_HANDLE_SIZE));
    Rectangle NE = new Rectangle(
        new Point(control.Location.X + control.Width,
            control.Location.Y - DRAG_HANDLE_SIZE),
        new Size(DRAG_HANDLE_SIZE, DRAG_HANDLE_SIZE));
    Rectangle W = new Rectangle(
        new Point(control.Location.X - DRAG_HANDLE_SIZE,
            control.Location.Y + control.Height/2 - DRAG_HANDLE_SIZE/2),
        new Size(DRAG_HANDLE_SIZE, DRAG_HANDLE_SIZE));
    Rectangle E = new Rectangle(
        new Point(control.Location.X + control.Width,
            control.Location.Y + control.Height/2 - DRAG_HANDLE_SIZE/2),
        new Size(DRAG_HANDLE_SIZE, DRAG_HANDLE_SIZE));
    Rectangle SW = new Rectangle(
        new Point(control.Location.X - DRAG_HANDLE_SIZE,
            control.Location.Y + control.Height),
        new Size(DRAG_HANDLE_SIZE, DRAG_HANDLE_SIZE));
    Rectangle S = new Rectangle(
        new Point(control.Location.X + control.Width/2 - DRAG_HANDLE_SIZE/2,
            control.Location.Y + control.Height),
        new Size(DRAG_HANDLE_SIZE, DRAG_HANDLE_SIZE));
    Rectangle SE = new Rectangle(
        new Point(control.Location.X + control.Width,
            control.Location.Y + control.Height),
        new Size(DRAG_HANDLE_SIZE, DRAG_HANDLE_SIZE));

    Graphics g = panel2.CreateGraphics();
    ControlPaint.DrawBorder(g, Border, Color.Gray, ButtonBorderStyle.Dotted);
    ControlPaint.DrawGrabHandle(g, NW, true, true);
    ControlPaint.DrawGrabHandle(g, N, true, true);
    ControlPaint.DrawGrabHandle(g, NE, true, true);
    ControlPaint.DrawGrabHandle(g, W, true, true);
    ControlPaint.DrawGrabHandle(g, E, true, true);
    ControlPaint.DrawGrabHandle(g, SW, true, true);
    ControlPaint.DrawGrabHandle(g, S, true, true);
    ControlPaint.DrawGrabHandle(g, SE, true, true);
    g.Dispose();
}

这里是TextBox_TextChanged 事件：

private void txtIDImg_TextChanged(object sender, EventArgs e)
{
    if (SelectedLabel == null) return;
    SelectedLabel.Text = txtIDImg.Text;
}

Answer 1

在您的control_MouseDown 中，您正在更改SelectedControl 和propertyGrid1.SelectedObject 属性，但在txtIDImg_TextChanged 中您设置了SelectedLabel.Text。 SelectedLabel 未在control_MouseDown 中设置。