Question

我在尝试在面板上绘制矩形时遇到问题。我创建了一个具有执行此功能的类，但是当我调用它时没有任何反应。当我使用函数中的代码而不是实际函数时，它可以工作。有任何想法吗？这是代码

    class Snake : Form1
    {
        public static int x = 20;
        public static int y = 20;
        public static int r = 20;

        public void Draw()
        {
            SolidBrush brush = new SolidBrush(Color.Green);
            Graphics G = panel1.CreateGraphics();
            G.FillRectangle(brush, x, y, r, r);
        }
    }

    //...

    private void panel1_MouseClick(object sender, MouseEventArgs e)
    {
        Snake s = new Snake();
        s.Draw();
    }

Answer 1

Snake对象在其自己的图形上下文中绘制，这与您单击的面板的上下文不同。要解决此问题，面板必须为<table class="tableau"> <thead> <tr><th>xxx</th><th><?=implode("</th><th>",array_column($lesFraisForfait, "libelle"))?></th></tr> </thead> <tbody> <tr><td>id frais</td><td><?=implode("</td><td>",array_column($lesFraisForfait, "idfrais"))?></td></tr> <tr><td>quantité</td><td><?=implode("</td><td>",array_column($lesFraisForfait, "quantite"))?></td></tr> </tbody> </table>函数提供图形：

Draw

在相关说明中，请务必始终处置class Snake { public static int x = 20; public static int y = 20; public static int r = 20; public void Draw(Graphics G) { SolidBrush brush = new SolidBrush(Color.Green); G.FillRectangle(brush, x, y, r, r); } } //... private void panel1_MouseClick(object sender, MouseEventArgs e) { using (Graphics G = panel1.CreateGraphics()) { Snake s = new Snake(); s.Draw(G); } }对象。

Answer 2

实施Panel Paint事件：

class Snake : Form1
{
    public static int x = 20;
    public static int y = 20;
    public static int r = 20;

    public void Draw()
    {
      panel1.Refresh() ;
    }

     private void panel1_Paint(object sender, PaintEventArgs e)
     {
        SolidBrush brush = new SolidBrush(Color.Green);
        Graphics G = panel1.CreateGraphics();
        G.FillRectangle(brush, x, y, r, r);
     }

}

Visual C＃ - 从类中调用函数什么都不做

2 个答案: