Question

我正在尝试创建一个程序，当您单击鼠标时会创建多个圆圈。问题是每次我点击另一个地方时它们都会消失（删除）。我创建了一个名为Ellipse的类，保存了我的圆圈。然后我把所有放在一个名为Ellipses的堆栈中。我已经查看了不同的解决方案，但仍删除旧的省略号。我想知道我做错了什么。

这是我的代码。

 public partial class Form1 : Form
{
    int x,y;
    Queue<MyEllipce> ellipses = new Queue<MyEllipce>();
    MyEllipce ellipse;

    public Form1()
    {
        InitializeComponent();
        this.MouseClick += new MouseEventHandler(Form1_MouseClick);

    }
    private void Form1_Load(object sender, EventArgs e)
    {
    }
    void Form1_MouseClick(object sender, MouseEventArgs e)
    {
        x = e.X;
        y = e.Y;
        ellipse = new MyEllipce(x, y);
        ellipses.Enqueue(ellipse);
        Invalidate();
    }

    private void btnTaBort_Click(object sender, EventArgs e)
    {
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);
        foreach (MyEllipce item in ellipses)
        {
            Graphics g = e.Graphics;
            MyEllipce ellipse= ellipses.Peek();
            ellipse.Draw(g, x, y);
        }
    }
}


class MyEllipce
{
    int x = 0;
    int y = 0;
    int diameter = 5;

    //Constructor
    public MyEllipce(int x, int y)
    {
        this.x = x;
        this.y = y;
    }

   public void Draw(Graphics g, int x, int y)
    {
        SolidBrush brush = new SolidBrush(Color.Red);
        g.FillEllipse(brush,x,y,diameter,diameter);
    }
}

Answer 1

更改此

SELECT DISTINCT 
          gastos.gastoID, 
          gastos.userID,
          tiposPagoGastos.tiposPagoID,
          tiposPago.tipoPago
FROM      gastos
LEFT JOIN tiposPagoGastos
ON gastos.gastoID = tiposPagoGastos.gastoID
LEFT JOIN tiposPago
ON tiposPagoGastos.tiposPagoID = tiposPago.tiposPagoID
WHERE     gastos.userID = 8

到此

ellipse.Draw(g, x, y);

删除“偷看”行。

在表单上绘制多个圆圈

1 个答案: