我有一個UWP UI,它包含一個GridView並且不使用Xaml。我想顯示完整的代碼隱藏構造項目。沒有Xaml模板。
我發現GridView的ChoosingItemContainer事件將允許我以編程方式創建GridViewItem實例,甚至可能重用它們。
但是,項目的自定義用戶界面並未實際顯示。
我注意到,滾動大量數據時,內容顯示非常簡短,然後消失。我猜測GridViewItem的內容正在被某種默認模板覆蓋。有沒有辦法禁用這個機器?
更一般地說,有沒有一種已知的方式來使用沒有Xaml的GridView + Items?
UPDATE:
下面是一個說明該問題的最小代碼示例。 將CustomGridView放置在用戶界面的某個位置。
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.UI;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Media;
namespace MyApp
{
// Some kind of data object
public class MyData
{
public string MyProperty;
}
// A custom GridViewItem
public class MyGridViewItem : GridViewItem
{
private TextBox mTextBox;
public MyGridViewItem()
{
mTextBox = new TextBox();
mTextBox.Width = 100;
mTextBox.Height = 100;
Content = mTextBox;
// Make the items visible at all: use red background
Background = new SolidColorBrush(Color.FromArgb(255,255,0,0));
}
public void SetData(MyData d)
{
mTextBox.Text = d.MyProperty;
// Content seems to be always reset to the data object itself.
Content = mTextBox;
// With the following line the contents appear briefly while the view is scrolling.
// Without this line the contents don't appear at all
Template = null;
}
}
// Custom grid. No Xaml.
public class CustomGridView : GridView
{
public CustomGridView()
{
this.ChoosingItemContainer += CustomGridView_ChoosingItemContainer;
// Create some data to show.
CollectionViewSource s = new CollectionViewSource();
ObservableCollection<MyData> oc = new ObservableCollection<MyData>();
for(int i = 0;i < 10000;i++)
{
MyData d = new MyData();
d.MyProperty = i.ToString();
oc.Add(d);
}
s.Source = oc;
ItemsSource = s.View;
}
private void CustomGridView_ChoosingItemContainer(ListViewBase sender,ChoosingItemContainerEventArgs args)
{
// Unchecked cast, but for the sake of simplicity let's assume it always works.
MyData d = (MyData)args.Item;
MyGridViewItem it = null;
if((args.ItemContainer != null) && (args.ItemContainer.GetType() == typeof(MyGridViewItem)))
it = (MyGridViewItem)args.ItemContainer;
else
it = new MyGridViewItem();
it.SetData(d);
args.ItemContainer = it;
args.IsContainerPrepared = true;
// This should probably go elsewhere, but for simplicity it's here :)
((ItemsWrapGrid)ItemsPanelRoot).ItemWidth = 100;
((ItemsWrapGrid)ItemsPanelRoot).ItemHeight = 100;
}
}
}
你能告訴你如何將'GridViewItems'添加到'GridView'嗎?沒有你的代碼,就沒有辦法找出問題所在,以及爲什麼會發生。請參閱[mcve] – AVK
我已用最小的示例更新了該問題。 – Pragma