Question

我想从DataGrid获取/计算所有已检查项目。我在DataGrid中有20个项目，如下图所示。在20个可见项目中，有14个或13个可见项目。当我通过单击全选按钮将所有项目标记为选中时，所有20个项目都被标记为选中状态。但是当我通过单击打印按钮来计数已检查项目时，计数显示它仅标记14.怎么回事？友善的帮助

Datagrid：

<DataGrid HorizontalAlignment="Left" Height="265" Margin="10,74,0,0" 
                  Name="GridTable" AutoGenerateColumns="False" VerticalAlignment="Top" Width="766" CanUserAddRows="False" IsReadOnly="False" SelectionMode="Single" SelectionUnit="Cell">

            <DataGrid.Resources>
                <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" 
                   Color="#0073c4"/>
            </DataGrid.Resources>

            <DataGrid.Columns>

                <DataGridCheckBoxColumn  Header="Select" Binding="{Binding IsSelected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>

                <DataGridTextColumn Header="Code" Width="1*" IsReadOnly="True"  Binding="{Binding Code}"/>

                <DataGridTextColumn Header="Name" Width="1*" IsReadOnly="True"  Binding="{Binding Name}"/>

            </DataGrid.Columns>

        </DataGrid>

全选按钮：

private void SelectAllBtn_Click(object sender, RoutedEventArgs e)
{
    for (int i = 0; i < GridTable.Items.Count; i++)
    {
        var item = GridTable.Items[i];

        Item itemm = (Item)GridTable.Items[i];
        itemm.IsSelected = true;

        var mycheckbox = GridTable.Columns[0].GetCellContent(item) as CheckBox;

        if (mycheckbox != null)
        {
            mycheckbox.IsChecked = true;
        }
    }
}

打印按钮单击：

private void Print_Click(object sender, RoutedEventArgs e)
{
    int count = 0;

    for (int i = 0; i < GridTable.Items.Count; i++)
    {
        var item = GridTable.Items[i];

        if (GridTable.Columns[0].GetCellContent(item) as CheckBox != null)
        {
            var mycheckbox = GridTable.Columns[0].GetCellContent(item) as CheckBox;

            if ((bool)mycheckbox.IsChecked)
            {
                count++;
                listTobePrint.Add(tableList[i]);
            }
        }
    }

    MessageBox.Show(count.ToString());

注意：此MessageBox.Show(count.ToString()); 数14

Item.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Inventory_Control.Classes
{
    class Item : INotifyPropertyChanged
    {
        private string id;
        private string code;
        private string name;
        private string description;
        private string quantity;
        private string availableQuantity;
        private string unitprice;
        private string subtotal;
        private string category;
        private string type;
        private string location;
        private string index;
        private bool _isSelected;

        public string Id
        {
            get { return id; }
            set
            {
                id = value;
                NotifyPropertyChanged("Id");
            }
        }
        public string Code
        {
            get { return code; }
            set
            {
                code = value;
                NotifyPropertyChanged("Code");
            }
        }
        public string Name
        {
            get { return name; }
            set
            {
                name = value;
                NotifyPropertyChanged("Name");
            }
        }
        public string Description
        {
            get { return description; }
            set
            {
                description = value;
                NotifyPropertyChanged("Description");
            }
        }
        public string Quantity
        {
            get { return quantity; }
            set
            {
                quantity = value;
                NotifyPropertyChanged("Quantity");
            }
        }
        public string AvailableQuantity
        {
            get { return availableQuantity; }
            set
            {
                availableQuantity = value;
                NotifyPropertyChanged("AvailableQuantity");
            }
        }
        public string UnitPrice
        {
            get { return unitprice; }
            set
            {
                unitprice = value;
                NotifyPropertyChanged("UnitPrice");
            }
        }
        public string SubTotal
        {
            get { return subtotal; }
            set
            {
                subtotal = value;
                NotifyPropertyChanged("SubTotal");
            }
        }
        public string Category
        {
            get { return category; }
            set
            {
                category = value;
                NotifyPropertyChanged("Category");
            }
        }
        public string Type
        {
            get { return type; }
            set
            {
                type = value;
                NotifyPropertyChanged("Type");
            }
        }
        public string Location
        {
            get { return location; }
            set
            {
                location = value;
                NotifyPropertyChanged("Location");
            }
        }
        public string Index
        {
            get { return index; }
            set
            {
                index = value;
                NotifyPropertyChanged("Index");
            }
        }

        public bool IsSelected
        {
            get { return _isSelected; }
            set
            {
                _isSelected = value;
                NotifyPropertyChanged("IsSelected");
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        private void NotifyPropertyChanged(String propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }
}

Answer 1

这是因为您的DataGrid使用行虚拟化。它告诉您真相-它只有14个选定的行，因为这就是呈现基础数据所需的全部。

CODE杂志的文章XAML Anti-Patterns: Virtualization有一个很好的解释。

我注意到您尚未对DataGrid进行数据绑定，您必须以编程方式添加行吗？访问所选项目的正确（正确）方法是，进入包含绑定了DataGrid的Item对象集合的视图模型，并对该集合进行迭代以找到所选项目。

从DataGrid获取所有检查的项目

1 个答案: