在C#中按数字排序TreeViewItems列表
Eri*_*ark 1 c# sorting wpf list treeviewitem
这个问题是对这个问题的跟进.我目前的总体目标是根据输入的值以数字升序添加到我的程序TreeViewItem(我的TreeViewItem运行时添加了子节点)header.
我收到使用一个答案ModelView,一个工具,我不是那么熟悉了,我也被告知,这可以通过使用来完成List的TreeViewItems.List由于我缺乏经验,我决定探索这个选项ModelView.
在我的研究,我了解到Lists的TreeViewItems有一点不同,因为你真的不喜欢你可以在引用它们array.这使得他们更难以完成工作.我将解释我当前的方法并发布我的代码.请引导我朝着正确的方向前进,并提供编码解决方案的答案.我目前仍然坚持我的treeViewListAdd功能.我在评论中编写了伪代码,用于解释我要对该区域进行的操作.
*注意:我是TreeViewItem从一个单独的窗口添加到我的
现在我的添加TreeViewItem过程包括:
- 检查输入的项目是否为数字(DONE)
if不是数字,break操作(DONE)else- 继续添加子项(DONE)- 检查重复的孩子(DONE)
if找到重复break操作(DONE)else- 继续(完成)- 创建
List的TreeViewItem(DONE -但没有实现) TreeViewItem为新子节点创建(DONE)- TVI
header是根据用户文字设置的textBox(DONE) - 传递给尝试添加到
List数字顺序的函数(问题区域) - 添加排序
List到TreeViewItem主窗口(问题区域)
我目前的代码:
//OKAY - Add child to TreeViewItem in Main Window
private void button2_Click(object sender, RoutedEventArgs e)
{
//STEP 1: Checks to see if entered text is a numerical value
string Str = textBox1.Text.Trim();
double Num;
bool isNum = double.TryParse(Str, out Num);
//STEP 2: If not numerical value, warn user
if (isNum == false)
MessageBox.Show("Value must be Numerical");
else //STEP 3: else, continue
{
//close window
this.Close();
//Query for Window1
var mainWindow = Application.Current.Windows
.Cast<Window1>()
.FirstOrDefault(window => window is Window1) as Window1;
//STEP 4: Check for duplicate
//declare TreeViewItem from mainWindow
TreeViewItem locations = mainWindow.TreeViewItem;
//Passes to function -- checks for DUPLICATE locations
CheckForDuplicate(locations.Items, textBox1.Text);
//STEP 5: if Duplicate exists -- warn user
if (isDuplicate == true)
MessageBox.Show("Sorry, the number you entered is a duplicate of a current Node, please try again.");
else //STEP 6: else -- create child node
{
//STEP 7
List<TreeViewItem> treeViewList = new List<TreeViewItem>();
//STEP 8: Creates child TreeViewItem for TVI in main window
TreeViewItem newLocation = new TreeViewItem();
//STEP 9: Sets Headers for new child nodes
newLocation.Header = textBox1.Text;
//STEP 10: Pass to function -- adds/sorts List in numerical ascending order
treeViewListAdd(ref treeViewList, newLocation);
//STEP 11: Add children to TVI in main window
//This step will of course need to be changed to add the list
//instead of just the child node
mainWindow.TreeViewItem.Items.Add(newLocation);
}
}
}
//STEP 4: Checks to see whether the header entered is a DUPLICATE
private void CheckForDuplicate(ItemCollection treeViewItems, string input)
{
for (int index = 0; index < treeViewItems.Count; index++)
{
TreeViewItem item = (TreeViewItem)treeViewItems[index];
string header = item.Header.ToString();
if (header == input)
{
isDuplicate = true;
break;
}
else
isDuplicate = false;
}
}
//STEP 10: Adds to the TreeViewItem list in numerical ascending order
private void treeViewListAdd(ref List<TreeViewItem> currentList, TreeViewItem addLocation)
{
//if there are no TreeViewItems in the list, add the current one
if (currentList.Count() == 0)
currentList.Add(addLocation);
else
{
//gets the index of the last item in the List
int lastItem = currentList.Count() - 1;
/*
if (value in header > lastItem)
currentList.Add(addLocation);
else
{
//iterate through list and add TreeViewItem
//where appropriate
}
**/
}
}
非常感谢您的帮助.我试图表明我一直在研究这个问题并尝试自己能做的一切.
根据要求,这是我的结构TreeView.从第3级到第3级的所有内容都由用户动态添加...
好.删除所有代码并从头开始.
1:在WPF中编写一行代码之前,必须先阅读MVVM.
<Window x:Class="MiscSamples.SortedTreeView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:cmp="clr-namespace:System.ComponentModel;assembly=WindowsBase"
Title="SortedTreeView" Height="300" Width="300">
<DockPanel>
<TextBox Text="{Binding NewValueString}" DockPanel.Dock="Top"/>
<Button Click="AddNewItem" DockPanel.Dock="Top" Content="Add"/>
<TreeView ItemsSource="{Binding ItemsView}" SelectedItemChanged="OnSelectedItemChanged">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding ItemsView}">
<TextBlock Text="{Binding Value}"/>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
</DockPanel>
</Window>
代码背后:
public partial class SortedTreeView : Window
{
public SortedTreeViewWindowViewModel ViewModel { get { return DataContext as SortedTreeViewWindowViewModel; } set { DataContext = value; } }
public SortedTreeView()
{
InitializeComponent();
ViewModel = new SortedTreeViewWindowViewModel()
{
Items = {new TreeViewModel(1)}
};
}
private void AddNewItem(object sender, RoutedEventArgs e)
{
ViewModel.AddNewItem();
}
//Added due to limitation of TreeViewItem described in http://stackoverflow.com/questions/1000040/selecteditem-in-a-wpf-treeview
private void OnSelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
ViewModel.SelectedItem = e.NewValue as TreeViewModel;
}
}
2:您可以注意到的第一件事是"守则背后"没有任何意义.它只是将功能委托给ViewModel(而不是ModelView,这是一个拼写错误)
这是为什么？
因为这是一个更好的方法.期.将应用程序逻辑/业务逻辑和数据分离并与 UI 分离是任何开发人员都应该遇到的最好的事情.
那么,ViewModel是关于什么的？
3: ViewModel公开Properties包含要在View中显示的Data,并Methods包含与Data一起操作的逻辑.
所以它很简单:
public class SortedTreeViewWindowViewModel: PropertyChangedBase
{
private string _newValueString;
public int? NewValue { get; set; }
public string NewValueString
{
get { return _newValueString; }
set
{
_newValueString = value;
int integervalue;
//If the text is a valid numeric value, use that to create a new node.
if (int.TryParse(value, out integervalue))
NewValue = integervalue;
else
NewValue = null;
OnPropertyChanged("NewValueString");
}
}
public TreeViewModel SelectedItem { get; set; }
public ObservableCollection<TreeViewModel> Items { get; set; }
public ICollectionView ItemsView { get; set; }
public SortedTreeViewWindowViewModel()
{
Items = new ObservableCollection<TreeViewModel>();
ItemsView = new ListCollectionView(Items) {SortDescriptions = { new SortDescription("Value",ListSortDirection.Ascending)}};
}
public void AddNewItem()
{
ObservableCollection<TreeViewModel> targetcollection;
//Insert the New Node as a Root node if nothing is selected.
targetcollection = SelectedItem == null ? Items : SelectedItem.Items;
if (NewValue != null && !targetcollection.Any(x => x.Value == NewValue))
{
targetcollection.Add(new TreeViewModel(NewValue.Value));
NewValueString = string.Empty;
}
}
}
看到？通过该AddNewItem()方法中的5行代码满足您的所有11个要求.没有Header.ToString()东西,没有任何东西,没有可怕的代码背后的方法.
简单,简单的属性和INotifyPropertyChanged.
排序怎么样？
4:排序由CollectionView,执行,它发生在ViewModel级别,而不是View Level.
为什么？
因为数据与UI中的可视化表示是分开的.
5:最后,这是实际的数据项:
public class TreeViewModel: PropertyChangedBase
{
public int Value { get; set; }
public ObservableCollection<TreeViewModel> Items { get; set; }
public CollectionView ItemsView { get; set; }
public TreeViewModel(int value)
{
Items = new ObservableCollection<TreeViewModel>();
ItemsView = new ListCollectionView(Items)
{
SortDescriptions =
{
new SortDescription("Value",ListSortDirection.Ascending)
}
};
Value = value;
}
}
这是一个保存数据的类,在本例中是一个intValue,因为你只关心数字,所以这是正确的数据类型,然后是一个ObservableCollection将保存子节点的数据,再次CollectionView负责排序.
6:每当你在WPF中使用DataBinding时(这对于所有这些MVVM都是必不可少的)你需要实现INotifyPropertyChanged,所以这是PropertyChangedBase所有ViewModes继承自的类:
public class PropertyChangedBase:INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
Application.Current.Dispatcher.BeginInvoke((Action) (() =>
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}));
}
}
无论在哪里有财产变化,您都需要通过以下方式通知:
OnPropertyChanged("PropertyName");
如在
OnPropertyChanged("NewValueString");
这就是结果:
只需复制并粘贴我的所有代码,
File -> New Project -> WPF Application然后自己查看结果.如果您需要我澄清任何事情,请告诉我.