c# - 如何在WinForms中按下按钮来绘制图像？

Question

我必须做这个编辑器(BPMN 编辑器)，但我被卡住了。我在表单中有这个按钮，上面有一个图像，我想要这个:当我单击该按钮，然后在 Canvas 上按下单击时(绘图区域)将按钮中的图像放在那里。

Answer 1

public class Shape
{
    public float X { get; set; }
    public float Y { get; set; }
    public Image Image { get; set; }
}

和代码:

    private string _currentTool;
    private readonly List<Shape> _shapes;

    private void Button1Click(object sender, EventArgs e)
    {
        _currentTool = "img";
    }

    private void PictureBox1MouseDown(object sender, MouseEventArgs e)
    {
        switch (_currentTool)
        {
            case "img":
                _shapes.Add(new Shape {Image = button1.Image, X = e.X, Y = e.Y});
                pictureBox1.Invalidate();
                break;
        }
    }

    private void PictureBox1Paint(object sender, PaintEventArgs e)
    {
        foreach (var shape in _shapes)
        {
            e.Graphics.DrawImage(shape.Image, shape.X, shape.Y);
        }
    }