C#函数调用的一个问题

[云中客]

函数定义：
public static void ThoroughCollisionDetection(List<BaseLabel> labels)
{

}

函数调用：
layCityLabel.LabelFilter = LabelCollisionDetection.ThoroughCollisionDetection;

问题：
为什么这里的LabelCollisionDetection.ThoroughCollisionDetection;函数调用没有给参数也能执行

[快溜]

还有上下文吗

[风骑士之怒]

public event Action<List<BaseLabel>> LabelFilter;

有个事件

[云中客]

[Quote=引用 1 楼 ssp2009 的回复:]
还有上下文吗
[/Quote]
有的，就是代码太长，没贴出来

[云中客]

[Quote=引用 2 楼 wknight_it 的回复:]
public event Action<List<BaseLabel>> LabelFilter;

有个事件
[/Quote]

函数定义部分在一个类中
你所说的这个定义是在那个类中还是在当前代码中？

[风骑士之怒]

你查看下layCityLabel类中，关于LabelFilter定义就好了

[PaulyJiang]

[Quote=引用 3 楼 sxycgxj 的回复:]
引用 1 楼 ssp2009 的回复:
还有上下文吗

有的，就是代码太长，没贴出来
[/Quote]
在 layCityLabel 这个对象的Class 中或者在其父类中

[云中客]

using System.Collections.Generic;

namespace SharpMap.Rendering
{
    /// <summary>
    /// Class defining delegate for label collision detection and static predefined methods
    /// </summary>
    public class LabelCollisionDetection
    {
        #region Delegates

        /// <summary>
        /// Delegate method for filtering labels. Useful for performing custom collision detection on labels
        /// </summary>
        /// <param name="labels"></param>
        /// <returns></returns>
        public delegate void LabelFilterMethod(List<BaseLabel> labels);

        #endregion

        #region Label filter methods

        /// <summary>
        /// Simple and fast label collision detection.
        /// </summary>
        /// <param name="labels"></param>
        public static void SimpleCollisionDetection(List<BaseLabel> labels)
        {
            labels.Sort(); // sort labels by intersectiontests of labelbox
            //remove labels that intersect other labels
            for (int i = labels.Count - 1; i > 0; i--)
                if (labels[i].CompareTo(labels[i - 1]) == 0)
                {
                    if (labels[i].Priority == labels[i - 1].Priority) continue;

                    if (labels[i].Priority > labels[i - 1].Priority)
                        labels.RemoveAt(i - 1);
                    else
                        labels.RemoveAt(i);
                }
        }

        /// <summary>
        /// Thorough label collision detection.
        /// </summary>
        /// <param name="labels"></param>
        public static void ThoroughCollisionDetection(List<BaseLabel> labels)
        {
            labels.Sort(); // sort labels by intersectiontests of labelbox
            //remove labels that intersect other labels
            for (int i = labels.Count - 1; i > 0; i--)
            {
                if (!labels[i].Show) continue;
                for (int j = i - 1; j >= 0; j--)
                {
                    if (!labels[j].Show) continue;
                    if (labels[i].CompareTo(labels[j]) == 0)
                        if (labels[i].Priority >= labels[j].Priority)
                        {
                            labels[j].Show = false;
                            //labels.RemoveAt(j);
                            //i--;
                        }
                        else
                        {
                            labels[i].Show = false;
                            //labels.RemoveAt(i);
                            //i--;
                            break;
                        }
                }
            }
        }

        #endregion
    }
}

[风骑士之怒]

看错了，委托

class LayCityLabel
    {
        public delegate void A(List<int> i);
        public A LabelFilter
        {
            get;
            set;
        }
    }

    class Program
    {
        public static void ThoroughCollisionDetection(List<int> labels)
        {
            foreach (int item in labels)
            {
                Console.WriteLine(item);
            }
        }
        static void Main(string[] args)
        {
            LayCityLabel layCityLabel = new LayCityLabel();
            layCityLabel.LabelFilter = ThoroughCollisionDetection;
            layCityLabel.LabelFilter(new List<int>() { 1, 2, 3, 4 });
            Console.Read();
        }
    }

[SQL777]

[Quote=引用 7 楼 sxycgxj 的回复:]
C# code

using System.Collections.Generic;

namespace SharpMap.Rendering
{
/// <summary>
/// Class defining delegate for label collision detection and static predefined methods
///……
[/Quote]
就是一个方法赋值给一个委托..

[gxmark]

[Quote=引用楼主 sxycgxj 的回复:]
函数定义：
public static void ThoroughCollisionDetection(List<BaseLabel> labels)
{

}

函数调用：
layCityLabel.LabelFilter = LabelCollisionDetection.ThoroughCollisionDetection;

问题：
为什么这里的LabelCollisi……
[/Quote]

这里应该不是函数调用，实际上是实例化一个委托对象，只是传递的参数是一个方法（函数）名

[迈克尔1998]

学习~