C#实现listview Group收缩扩展的方法_c#

本文实例讲述了c#实现listview group收缩扩展的方法。分享给大家供大家参考，具体如下：

1、本实例是完善了codeprofect上面charju老师“add group collapse behavior on a listview control”的一个限制（点击分组后面的图标不能收缩和扩展）；

2、本实列适用于win2008,vista；

3、仅供参考，如有更好的方法，望大家不吝交流~

完整代码如下（只需建一个windows工程，在窗体上拖一个listview控件，取名为aoc，右击编辑代码，把下面的代码粘到窗口就可以了~，但需要注意事件对应）：

using system;
using system.collections.generic;
using system.componentmodel;
using system.data;
using system.drawing;
using system.text;
using system.windows.forms;
using system.runtime.interopservices;
using system.diagnostics;
namespace listviewgroup
{
  public partial class mainform : form
  {
    public mainform()
    {
      initializecomponent();
    }
    [dllimport("user32.dll")]
    static extern int sendmessage(intptr window, int message, int wparam, ref lvhittestinfo lparam);
    [dllimport("user32.dll")]
    static extern int sendmessage(intptr window, int message, int wparam, intptr lparam);
    private void btcollapse_click(object sender, eventargs e)
    {
      setgroupcollapse(groupstate.collapsed | groupstate.collapsible);
    }
    private void btexpand_click(object sender, eventargs e)
    {
      setgroupcollapse(groupstate.expanded | groupstate.collapsible);
    }
    private void setgroupcollapse(groupstate state)
    {
      for (int i = 0; i <= aoc.groups.count; i++)
      {
        lvgroup group = new lvgroup();
        group.cbsize = marshal.sizeof(group);
        group.state = (int)state; // lvgs_collapsible 
        group.mask = 4; // lvgf_state 
        group.igroupid = i;
        intptr ip = intptr.zero;
        try
        {
          ip = marshal.allochglobal(group.cbsize);
          marshal.structuretoptr(group, ip, true);
          sendmessage(aoc.handle, 0x1000 + 147, i, ip); // #define lvm_setgroupinfo (lvm_first + 147) 
        }
        catch (exception ex)
        {
          system.diagnostics.trace.writeline(ex.message + environment.newline + ex.stacktrace);
        }
        finally
        {
          if (null != ip) marshal.freehglobal(ip);
        }
      }
    }
    private void mainform_load(object sender, eventargs e)
    {
      setgroupcollapse(groupstate.collapsible);
      for (int i = 0; i < aoc.groups.count; i++)
      {
        aoc.groups[i].tag = "expanded";
      }
    }
    private void aoc_mousedown(object sender, mouseeventargs e)
    {
      lvhittestinfo lvhitinfo = new lvhittestinfo();
      point p = new point(e.x, e.y);
      lvhitinfo.pt = p;
      try
      {
        int id = sendmessage(aoc.handle, 0x1000 + 18, -1, ref lvhitinfo);
        if (lvhitinfo.flags == 0x50000000)
        {
          if (aoc.groups[id].tag.tostring() =="expanded")
          {
            setgroupcollapseex(id, groupstate.collapsed | groupstate.collapsible);
            aoc.groups[id].tag = "collapsed";
          }
          else if ( aoc.groups[id].tag.tostring() == "collapsed")
          {
            setgroupcollapseex(id, groupstate.expanded | groupstate.collapsible);
            aoc.groups[id].tag = "expanded";
          }
        }
        //messagebox.show(string.format("result={0}   flags=0x{1:x}", id, lvhitinfo.flags));
      }
      catch (exception ex)
      {
        trace.writeline(ex.message + environment.newline + ex.stacktrace);
      }
      finally
      {
        ;
      }
    }
    private void setgroupcollapseex(int id, groupstate groupstate)
    {
      int i = id;
      lvgroup group = new lvgroup();
      group.cbsize = marshal.sizeof(group);
      group.state = (int)groupstate; // lvgs_collapsible 
      group.mask = 4; // lvgf_state 
      group.igroupid = i;
      intptr ip = intptr.zero;
      try
      {
        ip = marshal.allochglobal(group.cbsize);
        marshal.structuretoptr(group, ip, true);
        sendmessage(aoc.handle, 0x1000 + 147, i, ip); // #define lvm_setgroupinfo (lvm_first + 147) 
      }
      catch (exception ex)
      {
        system.diagnostics.trace.writeline(ex.message + environment.newline + ex.stacktrace);
      }
      finally
      {
        if (null != ip) marshal.freehglobal(ip);
      }
    }
  }
  [structlayout(layoutkind.sequential)]
  public struct lvgroup
  {
    public int cbsize;
    public int mask;
    [marshalas(unmanagedtype.lptstr)]
    public string pszheader;
    public int cchheader;
    [marshalas(unmanagedtype.lptstr)]
    public string pszfooter;
    public int cchfooter;
    public int igroupid;
    public int statemask;
    public int state;
    public int ualign;
  }
  public enum groupstate
  {
    collapsible = 8,
    collapsed = 1,
    expanded = 0
  }
  [structlayout(layoutkind.sequential)]
  public struct lvhittestinfo
  {
    public point pt;
    public int flags;
    public int iitem;
    public int isubitem;
    public int igroup;
  }
}

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