private void Form1_MouseClick(object sender, MouseEventArgs e)
{//点击空间对象显示属性信息
//根据鼠标的点击创建节点信息
GISVertex onevertex = new GISVertex((double)e.X, (double)e.Y);
double mindistance = Double.MaxValue;
int findid = -1;
//通过循环计算找出features数组中元素的中心点与点击位置最近的点
for (int i = 0; i < features.Count; i++)
{
double distance = features[i].spatialpart.centroid.Distance(onevertex);
if (distance < mindistance)
{
mindistance = distance;
findid = i;
}
}
if (mindistance > 5 || findid == -1)
{
MessageBox.Show("没有点实体或鼠标点击位置不准确！");
}
else
{
MessageBox.Show(features[findid].getAttribute(0).ToString());
}
}
private void button3_Click(object sender, EventArgs e)
{
double x = Convert.ToDouble(textBox1.Text);
double y = Convert.ToDouble(textBox2.Text);
GISVertex onevertex = new GISVertex(x, y);
polyvertexes.Add(onevertex);
GISPolygon onepoly = new GISPolygon(polyvertexes);
//获取属性信息
//string attribute = textBox3.Text;
//GISAttribute oneattribute = new GISAttribute();
//oneattribute.AddValue(attribute);
//新建一个GISFeature 并添加到features数组中
GISFeature onefeature = new GISFeature(onepoly, null);
features.Add(onefeature);
//画出这个GISFeature
Graphics graphics = this.CreateGraphics();
onefeature.draw(graphics, false, 0);
//参数分别是画笔 是否绘制属性 属性列表values的索引
}
public double Distance(GISVertex anothervertex)
{
return(centroid.Distance(anothervertex));
}
//public GISVertex Location; **previous code
//public string Attribute;
public GISPoint(GISVertex onevertex)
{
centroid = onevertex;
extent = new GISExtent(onevertex, onevertex);
}
public double Distance(GISVertex anothervertex)
{
return(Math.Sqrt((x - anothervertex.x) * (x - anothervertex.x)
- (y - anothervertex.y) * (y - anothervertex.y)));
}
public GISVertex upright; //外接矩形的左下和右上角的节点
public GISExtent(GISVertex _bottomleft, GISVertex _upright)
{
bottomleft = _bottomleft;
upright = _upright;
}
public void draw(Graphics graphics, GISVertex location, int index)
{
graphics.DrawString(values[index].ToString(), new Font("宋体", 20),
new SolidBrush(Color.Green), new PointF((int)(location.x), (int)(location.y)));
}
