windows 文件监控

本文深入探讨了Windows环境下文件监控的实现方式,包括FileSystemWatcher、SHChangeNotifyRegister和ReadDirectoryChangesW三个关键技术点,详细解释了它们的工作原理及应用场景。
前言: 最近学Windows shell外壳,偶然发现了SHChangeNotifyRegister这个神奇的函数,于是便用它写了个例程。 本帖不少思想来自帖子:未公开Windows API SHChangeNotifyRegister实现文件监控 基本介绍: 在Windows实现文件监控有三种方法,第一种是“虚拟文件系统驱动”方法,如windows 下的filemon,网上有很多关于他的分析。第二种方法是“HOOK API”方法,钩子技术。第三种方法是“消息机制”,从windows的文件通知消息获取系统的文件操作。但是这是文件操作完成以后,才通知的。所以只能进行监视监视,不能进行完全的控制。而消息机制当中,也有三种方法,(1)通过使用“未公开API SHChangeNotifyRegister 实现”;(2)通过 FindFirstChangeNotification 实现;(3)通过 ReadDirectoryChangesW 实现。第(2)(3)种方法只能针对一个在指定目录或子目录下发生的更改符合过滤条件时,进行监视。 而现在,易语言 中大部分消息机制监视文件使用FindFirstChangeNotification或ReadDirectoryChangesW + 线程实现的(例如:文件监控精灵 - 监控目录文件新建删除重命名修改 ),该方法效率较低,而且如果很多文件在短时间内发生变更,则有可能会丢失部分通知,且监视的文件信息有限,所以,我写了一份使用SHChangeNotifyRegister来监视文件的例程。 特性: 代码几乎是全注释,清晰明了: 程序很多命令和常量是翻译自MSDN,规范程度高: 监视多种消息(比如USB接口信息),很多问题一个命令即可解决:
//1.mesh构建 using System.Collections; using System.Collections.Generic; using UnityEngine; [RequireComponent(typeof(MeshFilter), typeof(MeshRenderer), typeof(MeshCollider))] public class Potteryprototype : MonoBehaviour {     MeshFilter meshFilter;     MeshRenderer meshRenderer;     MeshCollider meshCollider;     Mesh mesh;       public int details = 40;     public int layer = 20;     public float Height = 0.1f;       public float OuterRadius = 1.0f;     public float InnerRadius = 0.9f;       List<Vector3> vertices;     List<Vector2> UV;     List<int> triangles;       float EachAngle ;     int SideCount;       public MouseControl mouse;       void Start()     {         meshFilter = GetComponent<MeshFilter>();         meshCollider = GetComponent<MeshCollider>();         meshRenderer = GetComponent<MeshRenderer>();     }       [ContextMenu("GeneratePottery")]     void GeneratePrototype()     {         vertices = new List<Vector3>();         triangles = new List<int>();         UV = new List<Vector2>();           EachAngle = Mathf.PI * 2 / details;         for (int i = 0; i < layer; i++)         {             GenerateCircle(i);         }         Capping();                 mesh = new Mesh();         mesh.vertices = vertices.ToArray();         mesh.triangles = triangles.ToArray();         mesh.uv = UV.ToArray();           mesh.RecalculateBounds();         mesh.RecalculateTangents();           meshFilter.mesh = mesh;         mesh.RecalculateNormals();         meshCollider.sharedMesh = mesh;     }       void GenerateCircle(int _layer)     {         //外顶点与内顶点分开存储,方便变化操作时的计算         List<Vector3> vertices_outside = new List<Vector3>();         List<Vector3> vertices_inside = new List<Vector3>();                  List<Vector2> UV_outside = new List<Vector2>();         List<Vector2> UV_inside = new List<Vector2>();             //外侧和内侧顶点计算         //注意这里让每一圈的首尾重合了,也就是开始和结尾的顶点坐标一致         //目的是计算UV坐标时不会出现空缺         for (float i = 0; i <= Mathf.PI * 2+EachAngle; i += EachAngle)         {             Vector3 v1 = new Vector3(OuterRadius * Mathf.Sin(i),  _layer * Height, OuterRadius * Mathf.Cos(i));             Vector3 v2 = new Vector3(OuterRadius * Mathf.Sin(i),  (_layer +1)* Height, OuterRadius * Mathf.Cos(i));             Vector3 v3 = new Vector3(InnerRadius * Mathf.Sin(i),  _layer * Height, InnerRadius * Mathf.Cos(i));             Vector3 v4 = new Vector3(InnerRadius * Mathf.Sin(i),  (_layer+1) * Height, InnerRadius * Mathf.Cos(i));             vertices_outside.Add(v1); vertices_outside.Add(v2);             vertices_inside.Add(v3); vertices_inside.Add(v4);               Vector2 uv1 = new Vector2(i / Mathf.PI*2, _layer*1.0f / layer * 1.0f);             Vector2 uv2 = new Vector2(i / Mathf.PI*2, (_layer + 1)*1.0f / layer * 1.0f);             Vector2 uv3 = new Vector2(i / Mathf.PI*2, _layer*1.0f / layer * 1.0f);             Vector2 uv4 = new Vector2(i / Mathf.PI*2, (_layer + 1) *1.0f/ layer * 1.0f);             UV_outside.Add(uv1); UV_outside.Add(uv2);             UV_inside.Add(uv3); UV_inside.Add(uv4);         }         vertices.AddRange(vertices_outside);         vertices.AddRange(vertices_inside);           UV.AddRange(UV_outside);         UV.AddRange(UV_inside);           SideCount = vertices_outside.Count;         int j = vertices_outside.Count * _layer * 2;         int n = vertices_outside.Count;         for (int i = j; i < j + vertices_outside.Count - 2; i += 2)         {               triangles.Add(i); triangles.Add(i + 2); triangles.Add(i + 1);             triangles.Add(i + 2); triangles.Add(i + 3); triangles.Add(i + 1);               triangles.Add(i + n); triangles.Add(i + n + 1); triangles.Add(i + n + 2);             triangles.Add(i + n + 2); triangles.Add(i + n + 1); triangles.Add(i + n + 3);         }          }     //封顶,底面由于看不见就不用管了     void Capping()     {                 for (float i = 0; i <= Mathf.PI * 2+EachAngle; i += EachAngle)         {             Vector3 outer = new Vector3(OuterRadius * Mathf.Sin(i),layer * Height, OuterRadius * Mathf.Cos(i));             Vector3 inner= new Vector3(InnerRadius * Mathf.Sin(i), layer * Height, InnerRadius * Mathf.Cos(i));               vertices.Add(outer);vertices.Add(inner);               Vector2 uv1 = new Vector2(i / Mathf.PI * 2,0); Vector2 uv2 = new Vector2(i / Mathf.PI * 2, 1);                         UV.Add(uv1); UV.Add(uv2);         }         int j = SideCount * layer * 2;         for (int i=j;i<vertices.Count-2;i+=2)         {             triangles.Add(i);triangles.Add(i + 3);triangles.Add(i + 1);             triangles.Add(i);triangles.Add(i + 2);triangles.Add(i + 3);         }         triangles.Add(vertices.Count - 2);triangles.Add(j + 1);triangles.Add(vertices.Count - 1);         triangles.Add(vertices.Count - 2);triangles.Add(j);triangles.Add(j + 1);             } }   //2.动态改变形状 //这个函数放在Update()里调用     void GetMouseControlTransform()     {         //从屏幕鼠标位置发射一条射线到模型上,获取这个坐标         Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);         RaycastHit info;           if (Physics.Raycast(ray.origin, ray.direction, out info))         {               //在Unity中无法直接修改MeshFilter中Mesh的信息,需要新建一个Mesh修改其引用关系             Mesh mesh = meshFilter.mesh;             Vector3[] _vertices = mesh.vertices;               for (int i = 0; i < _vertices.Length; i++)             {                   //x,z平面变换                 //顶点移动与Y值的关系限制在5倍单层高度                 //这里可以自行修改,限制高度越大,曲线越平滑                 if (Mathf.Abs(info.point.y - transform.TransformPoint(_vertices[i]).y) < (5 * Height))                 {                     //计算顶点移动方向的向量                     Vector3 v_xz = (transform.TransformPoint(_vertices[i]) - new Vector3(transform.position.x, transform.TransformPoint(_vertices[i]).y, transform.position.z));                       //外顶点与内顶点移动时相对距离应该保持不变                     //因为我们知道顶点数组内的顺序关系,所以可以通过计算总顶点数除以每层单侧顶点数的商的奇偶关系来判断是外顶点还是内顶点                     int n = i / SideCount;                     bool side = n % 2 == 0;                     //判断顶面顶点内外关系                     bool caps = (i - (SideCount * layer * 2)) % 2 == 0;                       //限制每个顶点最大和最小的移动距离                     float max;                     float min;                     if (i < SideCount * layer * 2)                     {                         max = side ? 2f * OuterRadius : 2f * OuterRadius - (OuterRadius - InnerRadius);                           min = side ? 0.5f * OuterRadius : 0.5f * OuterRadius - (OuterRadius - InnerRadius);                     }                     else                     {                         max = caps ? 2f * OuterRadius : 2f * OuterRadius - (OuterRadius - InnerRadius); ;                         min = caps ? 0.5f * OuterRadius : 0.5f * OuterRadius - (OuterRadius - InnerRadius);                     }                     //计算当前顶点到鼠标Y值之间的距离,再用余弦函数算出实际位移距离                     float dif = Mathf.Abs(info.point.y - transform.TransformPoint(_vertices[i]).y);                     if (Input.GetKey(KeyCode.RightArrow))                     {                         float outer = max - v_xz.magnitude;                         _vertices[i] += v_xz.normalized * Mathf.Min(0.01f * Mathf.Cos(((dif / 5 * Height) * Mathf.PI) / 2), outer);                     }                     else if (Input.GetKey(KeyCode.LeftArrow))                     {                         float inner = v_xz.magnitude - min;                         _vertices[i] -= v_xz.normalized * Mathf.Min(0.01f * Mathf.Cos(((dif / 5 * Height) * Mathf.PI) / 2), inner);                     }                       //Y轴变换                     float scale_y = transform.localScale.y;                     if (Input.GetKey(KeyCode.UpArrow))                     {                         scale_y = Mathf.Min(transform.localScale.y + 0.000001f, 2.0f);                     }                     else if (Input.GetKey(KeyCode.DownArrow))                     {                           scale_y = Mathf.Max(transform.localScale.y - 0.000001f, 0.3f);                     }                     transform.localScale = new Vector3(transform.localScale.x, scale_y, transform.localScale.z);                   }                   mesh.vertices = _vertices;                 mesh.RecalculateBounds();                 mesh.RecalculateNormals();                 meshFilter.mesh = mesh;                 meshCollider.sharedMesh = mesh;             }         }     } }   //计算时就把顶点坐标系转换为自身坐标系,求得向量后再转换为世界坐标系     Vector3 v_xz = transform.TransformDirection(transform.InverseTransformPoint(_vertices[i]) - transform.InverseTransformPoint(new Vector3(0, _vertices[i].y, 0)));   //3.法线平均化 IEnumerator Print_Normals()     {              for (int i = 0; i < meshFilter.mesh.vertices.Length; i++)         {                if (i % 2 == 0)             {                 Debug.DrawRay(transform.TransformPoint(meshFilter.mesh.vertices[i]), transform.TransformDirection(meshFilter.mesh.normals[i] * 0.3f), Color.green, 1000f);             }             else             {                 Debug.DrawRay(transform.TransformPoint(meshFilter.mesh.vertices[i]), transform.TransformDirection(meshFilter.mesh.normals[i] * 0.3f), Color.blue, 1000f);             }               yield return new WaitForSeconds(Time.deltaTime);           }     }   //回到项目上来。这段法线计算的代码就不放上来了,大致就是根据顶点在数组中的下标去判断位置是否相同,然后把该顶点的法线相加即可。大家自己构建Mesh时的顶点顺序可能会不太一样。 以上代码是否有问题,请帮我完善
08-30
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