C#实现SHP文件读取与地图显示的完整教程

private void 打开ToolStripMenuItem_Click(object sender, EventArgs e)
{
    // 清空现有数据
    if (listPolygonshp != null) listPolygonshp.Clear();
    if (listPointShp != null) listPointShp.Clear();
    location = new PointF((this.Width - score) / 2, 25);

    // 打开文件对话框
    OpenFileDialog ofd = new OpenFileDialog();
    ofd.Filter = "shp文件|*.shp";
    if (ofd.ShowDialog() == DialogResult.Cancel) return;
    
    // 读取SHP文件
    kl.OpenShpFile(ofd.FileName);
    myds = kl.GetDataSet();//填充数据集
    
    // 显示文件头信息
    textBox1.Text = "";
    textBox1.Text += "文件代码：" + kl.GetFileCode() + "\r\n"
     + "文件长度：" + kl.GetFileLength() + "\r\n"
     // ... 其他文件头信息
}

private void transform(PointF[] points, int lenth)
{
    float width = (float)(kl.GetXMax() - kl.GetXMin());
    float height = (float)(kl.GetYMax() - kl.GetYMin());
    float wh = width / height;
    
    for (int i = 0; i < points.Length; i++)
    {
        points[i].X = (this.Width - lenth) / 2 + 
                     (points[i].X - (float)kl.GetXMin()) / width * lenth * wh;
        points[i].Y = lenth - (points[i].Y - (float)kl.GetYMin()) / height * lenth;
    }
}

public void DisplayShp()
{
    Bitmap bp = new Bitmap(pictureBox1.Width, pictureBox1.Height);
    Graphics g = Graphics.FromImage(bp);
    
    // 绘制点要素
    foreach (PointShp p in listPointShp)
    {
        SolidBrush bru = new SolidBrush(Color.Green);
        g.FillEllipse(bru, p.pf.X, p.pf.Y, 10, 10);
        // 添加标注
        g.DrawString(p.label, new Font("宋体", 9), Brushes.Black, 
                    new PointF(p.pf.X - 25, p.pf.Y));
    }
    
    // 绘制面要素
    foreach (PolygonShp ls in listPolygonshp)
    {
        Pen pen = new Pen(Color.Black, 2);
        g.DrawPolygon(pen, ls.Points);
        
        // 计算标注位置（面中心）
        float w = 0, h = 0;
        foreach (PointF pf in ls.Points)
        {
            w += pf.X;
            h += pf.Y;
        }
        g.DrawString(ls.label, new Font("宋体", 9), Brushes.Green, 
                    new PointF(w / ls.Points.Length - 25, h / ls.Points.Length));
    }
    
    pictureBox1.Image = bp;
    g.Dispose();
}

private void pictureBox1_MouseWheel(object sender, MouseEventArgs e)
{
    float zoomnum = e.Delta > 0 ? 1.1f : 0.9f;
    
    foreach(PolygonShp ls in listPolygonshp)
    {
        zoom(ls.Points, zoomnum);
    }
    
    foreach (PointShp p in listPointShp)
    {
        PointF[] pos = new PointF[1] { p.pf };
        zoom(pos, zoomnum);
        p.pf = pos[0];
    }
    
    DisplayShp();
}

private void zoom(PointF[] points, float zoomnum)
{
    for(int i = 0; i < points.Length; i++)
    {
        points[i].X = location.X + (points[i].X - location.X) * zoomnum;
        points[i].Y = location.Y + (points[i].Y - location.Y) * zoomnum;
    }
}

private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
    if(moving)
    {
        foreach(PolygonShp ls in listPolygonshp)
        {
            for(int i = 0; i < ls.Points.Length; i++)
            {
                ls.Points[i].X += e.X - xStart;
                ls.Points[i].Y += e.Y - yStart;
            }
        }
        
        foreach (PointShp p in listPointShp)
        {
            p.pf.X += e.X - xStart;
            p.pf.Y += e.Y - yStart;
        }
        
        xStart = e.X;
        yStart = e.Y;
        DisplayShp();
    }
}

public void FillProptyTable()
{
    dataGridView1.DataSource = myds.Tables[0];
}