Question

我是计算机科学家的学生。对于一个项目，我想在我的Winform上动态绘制线条，问题是我只能在winform上绘制并且其中的控件隐藏了我的绘图：

所以我做了很多研究，发现solution。几乎我发现的每个帖子都会导致这个链接。我直接在帖子的评论中问过，但似乎没有人对此感兴趣，所以我来到这里。

解决方案工作正常，但不是我希望它工作的方式。当Form加载时，它会在控件的顶部绘制我的线条，但之后它不再执行任何操作。我想尽可能多地刷新它。

我已经从上面的Code Project链接中复制了代码，并根据我的需要稍微改了一下，所以这就是我到目前为止所做的:(作为绘制我的线条的函数）

private void graphicalOverlay_Paint(object sender, PaintEventArgs e)
{
    Pen myPen;
    myPen = new Pen(Color.Red, 10);
    Graphics formGraphics = this.CreateGraphics();
    formGraphics.Clear(Color.White);
    formGraphics.DrawLine(myPen, Arm_1.PointA.X, Arm_1.PointA.Y, Arm_1.PointB.X, Arm_1.PointB.Y);
    myPen.Color = Color.Blue;
    formGraphics.DrawLine(myPen, Arm_2.PointA.X, Arm_2.PointA.Y, Arm_2.PointB.X, Arm_2.PointB.Y);


    Rectangle rect = this.ClientRectangle;
    rect.Inflate(-10, -10);

    Pen pen;

    pen = new Pen(Color.Red, 5);
    e.Graphics.DrawLine(pen, Arm_1.PointA.X, Arm_1.PointA.Y, Arm_1.PointB.X, Arm_1.PointB.Y);
    pen = new Pen(Color.Blue, 5);
    e.Graphics.DrawLine(pen, Arm_2.PointA.X, Arm_2.PointA.Y, Arm_2.PointB.X, Arm_2.PointB.Y);

    pen.Dispose();
    e.Dispose();
    myPen.Dispose();
    formGraphics.Dispose();

}

这是graphOverlay控件（直接从Code Project复制）

namespace CodeProject
{
    using System;
    using System.ComponentModel;
    using System.Drawing;
    using System.Windows.Forms;

    public partial class GraphicalOverlay : Component
    {
        public event EventHandler<PaintEventArgs> Paint;
        private Form form;

        public GraphicalOverlay()
        {
            InitializeComponent();
        }

        public GraphicalOverlay(IContainer container)
        {
            container.Add(this);

            InitializeComponent();
        }

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public Form Owner
        {
            get { return form; }
            set 
            {
                // The owner form cannot be set to null.
                if (value == null)
                    throw new ArgumentNullException();

                // The owner form can only be set once.
                if (form != null)
                    throw new InvalidOperationException();

                // Save the form for future reference.
                form = value;

                // Handle the form's Resize event.
                form.Resize += new EventHandler(Form_Resize);

                // Handle the Paint event for each of the controls in the form's hierarchy.
                ConnectPaintEventHandlers(form);
            }
        }

        private void Form_Resize(object sender, EventArgs e)
        {
            form.Invalidate(true);
        }

        private void ConnectPaintEventHandlers(Control control)
        {
            // Connect the paint event handler for this control.
            // Remove the existing handler first (if one exists) and replace it.
            control.Paint -= new PaintEventHandler(Control_Paint);
            control.Paint += new PaintEventHandler(Control_Paint);

            control.ControlAdded -= new ControlEventHandler(Control_ControlAdded);
            control.ControlAdded += new ControlEventHandler(Control_ControlAdded);

            // Recurse the hierarchy.
            foreach (Control child in control.Controls)
                ConnectPaintEventHandlers(child);
        }

        private void Control_ControlAdded(object sender, ControlEventArgs e)
        {
            // Connect the paint event handler for the new control.
            ConnectPaintEventHandlers(e.Control);
        }

        private void Control_Paint(object sender, PaintEventArgs e)
        {
            // As each control on the form is repainted, this handler is called.

            Control control = sender as Control;
            Point location;

            // Determine the location of the control's client area relative to the form's client area.
            if (control == form)
                // The form's client area is already form-relative.
                location = control.Location;
            else
            {
                // The control may be in a hierarchy, so convert to screen coordinates and then back to form coordinates.
                location = form.PointToClient(control.Parent.PointToScreen(control.Location));

                // If the control has a border shift the location of the control's client area.
                location += new Size((control.Width - control.ClientSize.Width) / 2, (control.Height - control.ClientSize.Height) / 2);
            }

            // Translate the location so that we can use form-relative coordinates to draw on the control.
            if (control != form)
                e.Graphics.TranslateTransform(-location.X, -location.Y);

            // Fire a paint event.
            OnPaint(sender, e);
        }

        private void OnPaint(object sender, PaintEventArgs e)
        {
            // Fire a paint event.
            // The paint event will be handled in     Form1.graphicalOverlay1_Paint().

            if (Paint != null)
                Paint(sender, e);
        }
    }
    }

namespace System.Windows.Forms
{
    using System.Drawing;

    public static class Extensions
    {
        public static Rectangle Coordinates(this Control control)
        {
            // Extend System.Windows.Forms.Control to have a Coordinates property.
            // The Coordinates property contains the control's form-relative location.
            Rectangle coordinates;
            Form form = (Form)control.TopLevelControl;

            if (control == form)
                coordinates = form.ClientRectangle;
            else
                coordinates = form.RectangleToClient(control.Parent.RectangleToScreen(control.Bounds));

            return coordinates;
        }
    }
}

所以我的问题是在启动程序时只调用一次“graphicalOverlay_Paint”函数。有人知道怎么称呼它吗？

我希望我一直都是具体的。这是我在这个论坛上的第一个问题，告诉我，如果我做错了什么。另外，英语不是我的母亲，对不起的错误。我希望有一个人可以帮助我。非常感谢阅读，并度过了美好的一天！

二万

编辑1：代码项目链接中RocketScientist的所有信用。

在Winform C中动态绘制控件##

0 个答案: