c#代码问题

[ladygaga1090]

 private void panel1_Paint(object sender, PaintEventArgs e)
        {
            Bitmap buffermap = new Bitmap(50, 50);
            Graphics buffergrp = Graphics.FromImage(buffermap);

            int m_gridspace = 20;

            Pen gridpen = new System.Drawing.Pen(Color.Red);
            for (int column = 0; column < (int)Math.Ceiling((double)this.panel1.Width / (double)m_gridspace); column++)
            {
                buffergrp.DrawLine(gridpen, new Point(column * m_gridspace, 0), new Point(column * m_gridspace, this.Height));
            }
            for (int row = 0; row < (int)Math.Ceiling((double)this.panel1.Height / (double)m_gridspace); row++)
            {
                buffergrp.DrawLine(gridpen, new Point(0, row * m_gridspace), new Point(this.Width, row * m_gridspace));
            }
        }

怎么就看不到画的线条呢？

[ladygaga1090]

感觉 Graphics和Panel么有什么关系。。学习中。

[白雪公猪905]

Graphics buffergrp = Graphics.FromImage(buffermap);
换成
Graphics buffergrp = e.Graphics;

[白雪公猪905]

如果你非要画在图像上。可以这样。

private void panel1_Paint(object sender, PaintEventArgs e)
        {
            //贴图位置
            Point p = new Point(50, 50);
            //画图
            e.Graphics.DrawImage(buffermap, p);
        }
        /// <summary>
        /// 图像
        /// </summary>
        private Bitmap buffermap;
        /// <summary>
        /// 绘图方法
        /// </summary>
        private void DrawImage()
        {
            buffermap = new Bitmap(50, 50);
            Graphics buffergrp = Graphics.FromImage(buffermap);

            int m_gridspace = 20;

            Pen gridpen = new System.Drawing.Pen(Color.Red);
            for (int column = 0; column < (int)Math.Ceiling((double)this.panel1.Width / (double)m_gridspace); column++)
            {
                buffergrp.DrawLine(gridpen, new Point(column * m_gridspace, 0), new Point(column * m_gridspace, this.Height));
            }
            for (int row = 0; row < (int)Math.Ceiling((double)this.panel1.Height / (double)m_gridspace); row++)
            {
                buffergrp.DrawLine(gridpen, new Point(0, row * m_gridspace), new Point(this.Width, row * m_gridspace));
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            DrawImage();
        }

楼主多看看GDI+的书吧