在Panel中SendMessage移动Label,AutoScroll=true,但不出现滚动条,求解.

[guojh021]

public partial class Form1 : Form
    {
        [DllImport("user32.dll")]
        public static extern bool ReleaseCapture();
        [DllImport("user32.dll")]
        public static extern bool SendMessage(System.IntPtr hwnd, int wMsg, int wParam, int lParam);
        public const int WM_SYSCOMMAND = 0x0112;
        public const int SC_MOVE = 0xF010;
        public const int HTCAPTION = 0x0002;
        public Form1()
        {
            InitializeComponent();
            this.panel1.AutoScroll = true;
        }

        private void label1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == System.Windows.Forms.MouseButtons.Left)
            {
                ReleaseCapture();
                SendMessage(label1.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0x0);
                this.panel1.Refresh();
                //如果label超出panel范围,不会出现滚动条,为什么?
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            label1.Left = this.panel1.Width - 20;///会出现滚动条
        }
    }

[guojh021]

顶起来吧~

[feiyun0112]

if (e.Button == System.Windows.Forms.MouseButtons.Left) { ReleaseCapture(); SendMessage(label1.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0x0); this.panel1.Refresh(); //如果label超出panel范围,不会出现滚动条,为什么? label1.Location = new Point(label1.Location.X+1, label1.Location.Y); label1.Location = new Point(label1.Location.X - 1, label1.Location.Y); }

[guojh021]

引用 2 楼 feiyun0112 的回复:

if (e.Button == System.Windows.Forms.MouseButtons.Left) { ReleaseCapture(); SendMessage(label1.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0x0); this.panel1.Refresh(); //如果label超出panel范围,不会出现滚动条,为什么? label1.Location = new Point(label1.Location.X+1, label1.Location.Y); label1.Location = new Point(label1.Location.X - 1, label1.Location.Y); }

我也想这样做.觉得有点傻....所以发个贴问问原因.

[guojh021]

label1.Left = label1.Left+1;
label1.Left = label1.Left-1;

[guojh021]