WPF DataPager控件

最近在项目中遇到远程加载数据的问题,由于服务器采用分页方式返回数据,因此客户端也相应的制作了一个分页控件.代码相对简单,算做入门级的源码.

 

效果如图:

初步分析,分页功能只需要3个核心变量:PageIndex,PageSize,TotalCount,2个事件:PageChanging,PageChanged,1个方法InitData.

PageIndex:记录当前所在页

PageSize:记录每页显示的条目数

TotalCount:条目总数

由TotalCount和PageSize可以得到PageCount

PageChanging事件作为分页的预处理事件,修改事件参数PageChangingEventArgs的IsCancel属性可以取消分页,这个是参考其他分页控件的属性

PageChanged事件是分页后的处理事件,应用程序可以在此时获取PageIndex进行操作.

InitData方法在数据加载时调用(主要是TotalCount属性),用于初始化上面提到的核心变量.

 

WPF提供了很强大和实用的Binding功能,在开发控件时,应该尽量把属性设计成依赖属性.因此我把PageIndex,PageSize,TotalCount属性全部设计成依赖属性,并注册了部分回调方法.这样也可以很方便的实现控件和ViewModel的绑定.

 

核心代码如下:

 

 

///
    /// DataPager.xaml 的交互逻辑
    ///
    public  partial  class  DataPager : UserControl, INotifyPropertyChanged
    {
        public  DataPager()
        {
            InitializeComponent();
        }
        ///
        /// 分页前处理的事件,如果设置e.IsCancel=True将取消分页
        ///
        public  event  PageChangingRouteEventHandler PageChanging;
        ///
        /// 分页后处理的事件
        ///
        public  event  PageChangedRouteEventHandler PageChanged;

        #region 依赖属性
        ///
        /// 当前页
        ///
        public  int  PageIndex
        {
            get  {  return  ( int )GetValue(PageIndexProperty); }
            set  { SetValue(PageIndexProperty, value); }
        }

        // Using a DependencyProperty as the backing store for CurrentPage.  This enables animation, styling, binding, etc...
        public  static  readonly  DependencyProperty PageIndexProperty =
            DependencyProperty.Register( "PageIndex" ,  typeof ( int ),  typeof (DataPager),  new  UIPropertyMetadata(1, (sender, e) =>
            {
                var  dp = sender  as  DataPager;
                dp.ChangeNavigationButtonState();
            }));


        ///
        /// 每页显示数据大小
        ///
        public  int  PageSize
        {
            get  {  return  ( int )GetValue(PageSizeProperty); }
            set  { SetValue(PageSizeProperty, value); InitData(); }
        }

        // Using a DependencyProperty as the backing store for PageSize.  This enables animation, styling, binding, etc...
        public  static  readonly  DependencyProperty PageSizeProperty =
            DependencyProperty.Register( "PageSize" ,  typeof ( int ),  typeof (DataPager),  new  UIPropertyMetadata(20, (sender, e) =>
            {
                var  dp = sender  as  DataPager;
                if  (dp ==  null )  return ;
                dp.ChangeNavigationButtonState();
            }));


        ///
        /// 记录数量
        ///
        public  int  TotalCount
        {
            get  {  return  ( int )GetValue(TotalCountProperty); }
            set
            {
                SetValue(TotalCountProperty, value);
            }
        }

        // Using a DependencyProperty as the backing store for TotalCount.  This enables animation, styling, binding, etc...
        public  static  readonly  DependencyProperty TotalCountProperty =
            DependencyProperty.Register( "TotalCount" ,  typeof ( int ),  typeof (DataPager),  new  UIPropertyMetadata(0, (sender, e) =>
            {
                var  dp = sender  as  DataPager;
                if  (dp ==  null )  return ;
                dp.InitData();
                dp.ChangeNavigationButtonState();
            }));


        ///
        /// 总页数
        ///
        public  int  PageCount
        {
            get  {  return  ( int )GetValue(PageCountProperty); }
            private  set  { SetValue(PageCountProperty, value); }
        }

        // Using a DependencyProperty as the backing store for PageCount.  This enables animation, styling, binding, etc...
        public  static  readonly  DependencyProperty PageCountProperty =
            DependencyProperty.Register( "PageCount" ,  typeof ( int ),  typeof (DataPager),  new  UIPropertyMetadata(1));



        ///
        /// 是否可以点击首页和上一页按钮
        ///
        public  bool  CanGoFirstOrPrev
        {
            get
            {
                if  (PageIndex <= 1)  return  false ;
                return  true ;
            }
        }
        ///
        /// 是否可以点击最后页和下一页按钮
        ///
        public  bool  CanGoLastOrNext
        {
            get
            {
                if  (PageIndex >= PageCount)  return  false ;
                return  true ;
            }
        }
        #endregion
        ///
        /// 点击首页按钮
        ///
        ///
        ///
        private  void  btnFirst_Click( object  sender, RoutedEventArgs e)
        {
            OnPageChanging(1);
        }
        ///
        /// 点击上一页按钮
        ///
        ///
        ///
        private  void  btnPrev_Click( object  sender, RoutedEventArgs e)
        {
            OnPageChanging( this .PageIndex - 1);
        }
        ///
        /// 点击下一页按钮
        ///
        ///
        ///
        private  void  btnNext_Click( object  sender, RoutedEventArgs e)
        {
            OnPageChanging( this .PageIndex + 1);
        }
        ///
        /// 点击末页按钮
        ///
        ///
        ///
        private  void  btnLast_Click( object  sender, RoutedEventArgs e)
        {
            OnPageChanging( this .PageCount);
        }
        ///
        /// 点击跳转按钮
        ///
        ///
        ///
        private  void  btnGoTo_Click( object  sender, RoutedEventArgs e)
        {
            int  pageIndex = 1;
            try
            {
                pageIndex = Convert.ToInt32(txtPageIndex.Text);
            }
            catch
            {

            }
            finally
            {
                OnPageChanging(pageIndex);
            }
        }
        ///
        /// 页码更改
        ///
        ///
        internal  void  OnPageChanging( int  pageIndex)
        {
            if  (pageIndex < 1) pageIndex = 1;
            if  (pageIndex >  this .PageCount) pageIndex =  this .PageCount;

            var  oldPageIndex =  this .PageIndex;
            var  newPageIndex = pageIndex;
            var  eventArgs =  new  PageChangingEventArgs() { OldPageIndex = oldPageIndex, NewPageIndex = newPageIndex };
            if  ( this .PageChanging !=  null )
            {
                this .PageChanging( this , eventArgs);
            }
            if  (!eventArgs.IsCancel)
            {
                this .PageIndex = newPageIndex;
                if  ( this .PageChanged !=  null )
                {
                    this .PageChanged.Invoke( this ,  new  PageChangedEventArgs() { CurrentPageIndex =  this .PageIndex });
                }
            }
        }
        ///
        /// 通知导航按钮(首页,上一页,下一页,末页)状态的更改
        ///
        void  ChangeNavigationButtonState()
        {
            this .NotifyPropertyChanged( "CanGoFirstOrPrev" );
            this .NotifyPropertyChanged( "CanGoLastOrNext" );
        }
        ///
        /// 初始化数据
        ///
        void  InitData()
        {
            if  ( this .TotalCount == 0)
            {
                this .PageCount = 1;
            }
            else
            {
                this .PageCount =  this .TotalCount %  this .PageSize > 0 ? ( this .TotalCount /  this .PageSize) + 1 :  this .TotalCount /  this .PageSize;
            }
            if  ( this .PageIndex < 1)
            {
                this .PageIndex = 1;
            }
            if  ( this .PageIndex >  this .PageCount)
            {
                this .PageIndex =  this .PageCount;
            }
            if  ( this .PageSize < 1)
            {
                this .PageSize = 20;
            }
        }


        #region INotifyPropertyChanged成员
        public  event  PropertyChangedEventHandler PropertyChanged;
        public  void  NotifyPropertyChanged( string  propertyName)
        {
            if  ( this .PropertyChanged !=  null )
            {
                this .PropertyChanged.Invoke( this ,  new  PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion
    }

 

Xaml中使用如下:

下载位置：http://pan.baidu.com/s/1c26s3DY

转载于:https://www.cnblogs.com/wlming/p/5420589.html