Question

编辑：这不是“如何在C＃中使用OnPaint事件”的副本，因为我甚至不知道它存在。当我不知道答案时，我问了一个问题。这就像是在询问“我怎么检查汽车里的油”时，我甚至不知道什么是蘸棒。如果这样做是为了解释为什么它不是重复的话，请删除重复的标志。

我正在尝试制作一个随机地形生成器。目前，我正在使用Windows Forms Graphics来绘制所有内容。我似乎无法使引擎工作。运行以下代码不会在窗体上显示任何内容，即使它应该绘制一个从0,0到50,50的黑色矩形。谁能解决？

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Random_Terrain_Generator
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            Engine e = new Engine(100, 100);
            e.Color3(Color.Blue);
            e.rect(new Rectangle(0,0,50,50));
            Graphics fg = this.CreateGraphics();
            fg.DrawImage(e.getBuffer(), 1, 100, 100, 100);
        }
    }

    public class Engine
    {
        Color fillColor;
        Bitmap buffer;
        Graphics bufferGraphics;

        public Engine(int bufferWidth, int bufferHeight)
        {
            buffer = new Bitmap(bufferWidth, bufferHeight);
            bufferGraphics = Graphics.FromImage(buffer);
        }

        public void fRect(Rectangle r)
        {
            bufferGraphics.FillRectangle(new SolidBrush(fillColor), r);
        }

        public void rect(Rectangle r)
        {
            bufferGraphics.DrawRectangle(new Pen(fillColor), r);
        }

        public void Color3(Color c)
        {
            fillColor = c;
        }

        public Bitmap getBuffer()
        {
            return buffer;
        }
    }
}

Answer 1

这很有效！感谢TyCobb的快速回答。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Random_Terrain_Generator
{
    public partial class Form1 : Form
    {
        Engine e;

        public Form1()
        {
            InitializeComponent();

            e = new Engine(100, 100);
            e.Color3(Color.Blue);
            e.fRect(new Rectangle(0,0,50,50));
        }

        protected override void OnPaint(PaintEventArgs pe)
        {
            // Call the OnPaint method of the base class.
            base.OnPaint(pe);
            pe.Graphics.DrawImage(e.getBuffer(), 1, 1, 100, 100);

        }
    }

    public class Engine
    {
        Color fillColor;
        Bitmap buffer;
        Graphics bufferGraphics;

        public Engine(int bufferWidth, int bufferHeight)
        {
            buffer = new Bitmap(bufferWidth, bufferHeight);
            bufferGraphics = Graphics.FromImage(buffer);
        }

        public void fRect(Rectangle r)
        {
            bufferGraphics.FillRectangle(new SolidBrush(fillColor), r);
        }

        public void rect(Rectangle r)
        {
            bufferGraphics.DrawRectangle(new Pen(fillColor), r);
        }

        public void Color3(Color c)
        {
            fillColor = c;
        }

        public Bitmap getBuffer()
        {
            return buffer;
        }
    }
}

我覆盖了表单的OnPaint事件，该事件每帧重绘一次矩形。问题是表单是在矩形上绘画。 How to use the OnPaint event in C#?

为什么在构造函数中的表单上绘制不会在表单上显示任何内容？

1 个答案: