滚轮翻页与传动的翻页更为方便，经过本人一番探讨与琢磨终于在XtraGrid的GridView中实现了鼠标滚轮翻页。
我新建了一个组件继承原本的GridControl，在组件中添加了一个ImageList,专门存放一些资源图片。用于实现动态图的效果。
添加一个自定义委托的参数与枚举，委托参数用于传递分页的信息。
public class PagingEventArgs : EventArgs
{ public int PageSize { get; set; } public int PageIndex { get; set; }
} public enum LoadState
{
/// <summary>
/// 就绪 /// </summary> Ready, /// <summary>
/// 正在读取 /// </summary> Loading, /// <summary>
/// 读取完成 /// </summary> Finish
}
在组件的类里面添加以下字段
/// <summary> /// 页面大小 /// </summary> private int _int_page_size=20; /// <summary> /// 当前页索引 /// </summary> private int _int_page_index=1; /// <summary> /// 总记录数 /// </summary> private int _int_record_count; /// <summary> /// 读取状态 /// </summary> private LoadState _LodaState_state;
添加以下属性
(!IsPaging) (!IsPaging) = (value>,
else
{
while (this.MainView.DataRowCount > 0)
GridView_main_view.DeleteRow(0);
this.RefreshDataSource();
}
}
} /// <summary>
/// 每次读取的行数 /// </summary>
public int PageSize
{ get
{ if (!IsPaging) return 0; return _int_page_size;
} set
{ if (!IsPaging) return ;
_int_page_size = value;
}
} /// <summary>
/// 总页数 /// </summary>
private int PageCount
{ get
{ if (RecordCount % PageSize == 0) return RecordCount / PageSize; return RecordCount / PageSize + 1;
}
} /// <summary>
/// Grid /// </summary>
private GridView _GridView_main_view
{ get { return (GridView)this.MainView; }
} /// <summary>
/// 是否启用分页 /// </summary>
public bool IsPaging { get; set; }
添加以下委托与事件
/// <summary> /// 内部使用的委托 /// </summary> private delegate void myDelegate(); /// <summary> /// 滚动翻页的委托 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> public delegate void ScrollingToPageEventHandler(object sender, PagingEventArgs e); /// <summary> /// 滚动翻页的事件 /// </summary> public event ScrollingToPageEventHandler OnScrollingToPage;
以下则是一些对控件的设置，按照各人喜好可以有所更改。
/// <summary>
/// 设置分页栏 /// </summary>
private void InitEmbeddedNavigator()
{this.EmbeddedNavigator.CustomButtons.AddRange(new DevExpress.XtraEditors.NavigatorCustomButton[] { new DevExpress.XtraEditors.NavigatorCustomButton(-1, -1, true, false, "", null)}); this.EmbeddedNavigator.TextStringFormat = " 当前 {1} 行数据 "; this.UseEmbeddedNavigator = true;
} /// <summary>
/// 设置gridView /// </summary>
private void InitGridView()
{
_GridView_main_view.TopRowChanged += new EventHandler(gridView_TopRowChanged);
}
为控件的事件注册以下方法
private void gridControl_Load(object sender, EventArgs e)
{ if (IsPaging)
{
_LodaState_state = LoadState.Ready;
InitEmbeddedNavigator();
InitGridView();
}
} private void gridView_TopRowChanged(object sender, EventArgs e)
{ lock (this)
{ if ( _int_page_index > PageCount || _LodaState_state != LoadState.Ready) return;
} //检查是否到达底部
if (_GridView_main_view.IsRowVisible(_GridView_main_view.RowCount - 1) == RowVisibleState.Visible||
_int_page_index==1)
{ lock (this)//设置成开始读取状态 {
_LodaState_state = LoadState.Loading;
}
Thread thread_load_data = new Thread(new ThreadStart(LoadData));
Thread thread_change_text = new Thread(new ThreadStart(ChangeLoadingImage));
thread_change_text.Start();
thread_load_data.Start();
}
}
TopRowChanged事件在grid的首行改变了就会触发，类似于滚动条的Scroll事件。这里开了两个线程，第一个线程用于读取数据，第二个线程用于实现动态图。两个线程调用的方法都在下面
top_row_index = focus_index = (== (OnScrollingToPage == Exception(= = = (.Parent.Invoke( myDelegate(== (= LoadState.Finish; image_index = (.Parent.InvokeRequired).Parent.Invoke( myDelegate(.EmbeddedNavigator.Buttons.CustomButtons[].Visible = () ( (_LodaState_state != LoadState.Loading) (image_index == = ++ ( .Parent.Invoke( myDelegate(.EmbeddedNavigator.Buttons.CustomButtons[].ImageIndex = (.Parent.InvokeRequired).Parent.Invoke( myDelegate(.EmbeddedNavigator.Buttons.CustomButtons[].Visible = (= ++
不过这个代码有点问题，当GridControl绑定的数据源有相同实例的子项时，随着RefreshData方法的调用会不停触发TopRowChanged事件，确切的原因还没搞清楚，解决这个问题就是要不去除数据源上相同的实例子项，要不就不调用RefreshData方法。还有更好的办法还请高手们的指点。
原文地址：http://zhanglida66.blog.51cto.com/12834458/1920867
