如何分页WPF DataGrid？ [英] How can I paginate a WPF DataGrid?
问题描述
如何在wpf DataGrid 中设置分页？
How can I set paging in a wpf DataGrid?
推荐答案
上面的代码项目文章对于使用ADO表完成这个工作是非常好的。虽然在大多数应用程序中，它可能会运行得很好，而且易于理解，但是还可以使用更多的WPF-zen-like方式来实现它，也就是使用CollectionViews。与上面的示例相比，使用CollectionView的优点在于，您将什么数据放在网格中是一个比较笼统的一点（而不是你不能使这个例子更为普遍），并且它适合与一般的WPF数据绑定模型。如果您需要这些功能，它将为您提供支持常见操作（如排序，分组等）的地方。
The code project article above is quite good for getting this done with ADO tables. While for most applications, it is likely to work great, and is easy to understand, there is a more "WPF-zen-like" way to do it as well, and that would be using CollectionViews. The advantage of using a CollectionView compared to the example above is that it is a bit more general in terms of what data you're putting in your grid (not that you can't make that example more general), and it fits in well with the general WPF databinding model. It gives you a place to support common operations like sorting, grouping, etc, if you need those.
我将一个简单的几个简单的PagingCollectionView示例绑定到.NET 4.0 DataGrid控件。虽然这个例子本身是微不足道的，它至少显示了如何开始，因为你有一个关于实际的数据集合的代理，您可以在其上执行诸如MoveToNextPage和MoveToPreviousPage之类的简单操作。
I put together a very short example of a barely working PagingCollectionView bound to the .NET 4.0 DataGrid control. While the example itself is pretty trivial, it shows you at least how to get started, as you have a proxy around the actual collection of data on which you can execute simple operations like MoveToNextPage and MoveToPreviousPage.
这里是Window事件处理和PagingCollectionView的C＃：
Here's the C# for both the Window event handling and the PagingCollectionView:
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows;
using System.Windows.Data;
namespace GridPagingExample
{
public partial class MainWindow : Window
{
private readonly PagingCollectionView _cview;
public MainWindow()
{
InitializeComponent();
this._cview = new PagingCollectionView(
new List<object>
{
new { Animal = "Lion", Eats = "Tiger" },
new { Animal = "Tiger", Eats = "Bear" },
new { Animal = "Bear", Eats = "Oh my" },
new { Animal = "Wait", Eats = "Oh my isn't an animal" },
new { Animal = "Oh well", Eats = "Who is counting anyway" },
new { Animal = "Need better content", Eats = "For posting on stackoverflow" }
},
2
);
this.DataContext = this._cview;
}
private void OnNextClicked(object sender, RoutedEventArgs e)
{
this._cview.MoveToNextPage();
}
private void OnPreviousClicked(object sender, RoutedEventArgs e)
{
this._cview.MoveToPreviousPage();
}
}
public class PagingCollectionView : CollectionView
{
private readonly IList _innerList;
private readonly int _itemsPerPage;
private int _currentPage = 1;
public PagingCollectionView(IList innerList, int itemsPerPage)
: base(innerList)
{
this._innerList = innerList;
this._itemsPerPage = itemsPerPage;
}
public override int Count
{
get
{
if (this._innerList.Count == 0) return 0;
if (this._currentPage < this.PageCount) // page 1..n-1
{
return this._itemsPerPage;
}
else // page n
{
var itemsLeft = this._innerList.Count % this._itemsPerPage;
if (0 == itemsLeft)
{
return this._itemsPerPage; // exactly itemsPerPage left
}
else
{
// return the remaining items
return itemsLeft;
}
}
}
}
public int CurrentPage
{
get { return this._currentPage; }
set
{
this._currentPage = value;
this.OnPropertyChanged(new PropertyChangedEventArgs("CurrentPage"));
}
}
public int ItemsPerPage { get { return this._itemsPerPage; } }
public int PageCount
{
get
{
return (this._innerList.Count + this._itemsPerPage - 1)
/ this._itemsPerPage;
}
}
private int EndIndex
{
get
{
var end = this._currentPage * this._itemsPerPage - 1;
return (end > this._innerList.Count) ? this._innerList.Count : end;
}
}
private int StartIndex
{
get { return (this._currentPage - 1) * this._itemsPerPage; }
}
public override object GetItemAt(int index)
{
var offset = index % (this._itemsPerPage);
return this._innerList[this.StartIndex + offset];
}
public void MoveToNextPage()
{
if (this._currentPage < this.PageCount)
{
this.CurrentPage += 1;
}
this.Refresh();
}
public void MoveToPreviousPage()
{
if (this._currentPage > 1)
{
this.CurrentPage -= 1;
}
this.Refresh();
}
}
}
这是窗口的XAML ：
Here's the XAML for the window:
<Window x:Class="GridPagingExample.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<StackPanel Orientation="Horizontal" Grid.Row="0">
<Label Grid.Row="0" Margin="2">
<Label.Content>
<Binding Path="CurrentPage">
<Binding.StringFormat>Current Page: {0}</Binding.StringFormat>
</Binding>
</Label.Content>
</Label>
<Button Content="Next" Click="OnNextClicked" Margin="2"/>
<Button Content="Previous" Click="OnPreviousClicked" Margin="2"/>
</StackPanel>
<DataGrid ItemsSource="{Binding}" Grid.Row="1">
<DataGrid.Columns>
<DataGridTextColumn Header="Animal" Width="*" Binding="{Binding Animal}"/>
<DataGridTextColumn Header="Eats" Width="*" Binding="{Binding Eats}"/>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Window>
您可以构建这个CollectionView来支持更多的功能，比如MoveToLastPage和MoveToFirstPage，还有一些这将需要更多的思考你想要它的行为，如排序。希望是有帮助的
You could build out this CollectionView to support more functionality, some trivial, like MoveToLastPage and MoveToFirstPage, and some that will take some more thought about how you want it to behave, such as sorting. Hope it is helpful.
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