0

我试图通过 MVVM 模式获得有关 WPF 的技能。我几乎完成了具有基本功能的表格，但面临两个问题

1) 我的 Gridview 更改事件未触发 2) 插入记录后如何刷新网格

我的 ViewModel 和 View 代码如下

查看模型

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows.Input;
using DatabaseLayer;
using System.Data;

namespace WPFnMVVM.ViewModel 
{
    public class ContactsViewModel : WPFnMVVM.Common.VMBase
    {
        #region Variables
        private int _Id;
        private string _First_Name;
        private string _Last_Name;
        private DateTime _DOB;
        private clstbl_Contacts _Contacts;
        public WPFnMVVM.Common.RelayCommand _addCommand;
        public DataTable _tblContacts;
        #endregion

        public ContactsViewModel()
        {

            _tblContacts = LoadContacts();
        }


        #region Public Properties
        public int Id
        {
            get { return _Id; }
            set { _Id = value; OnPropertyChanged("Id"); }
        }
        public string First_Name
        {
            get { return _First_Name; }
            set { _First_Name = value; OnPropertyChanged("First_Name"); }
        }
        public string Last_Name
        {
            get { return _Last_Name; }
            set { _Last_Name = value; OnPropertyChanged("Last_Name"); }
        }
        public DateTime DOB
        {
            get { return _DOB; }
            set { _DOB = value; OnPropertyChanged("DOB"); }
        }
        public clstbl_Contacts Contacts
        {
            get { return _Contacts; }
            set
            {
                _Contacts = value;
                OnPropertyChanged("Contacts");
            }


        }

        public DataTable ContactsList
        {
            get { return _tblContacts; }
            set
            {
                _tblContacts = value;
                OnPropertyChanged("ContactsList");
            }
        }
        #endregion

        #region Private Methods
        private DataTable LoadContacts()
        {
            clstbl_Contacts objContact = new clstbl_Contacts(WPFnMVVM.Common.clsSettings.ConStr);
            {
                return objContact.Select();


            };
        }

        private void AddContacts()
        {
            clstbl_Contacts objContacts = new clstbl_Contacts(WPFnMVVM.Common.clsSettings.ConStr);
            objContacts.First_Name = First_Name;
            objContacts.Last_Name = Last_Name;
            objContacts.DOB = DOB;
            objContacts.Insert();
        }

        #endregion

        #region Commands
          public ICommand AddCommand
        {
            get
            {
                if (_addCommand == null)
                {
                    _addCommand = new WPFnMVVM.Common.RelayCommand(
                        param => this.AddContacts(),
                        param => true
                        );
                }
                return _addCommand;
            }
        }
        #endregion

    }
}

看法

<Window x:Class="WPFnMVVM.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:VM="clr-namespace:WPFnMVVM.ViewModel"
        xmlns:View="clr-namespace:WPFnMVVM"
        Title="MainWindow" Height="350" Width="337">
    <Window.DataContext>
        <VM:ContactsViewModel/>
    </Window.DataContext>
    <Grid Name="MyGrid">
        <TextBox HorizontalAlignment="Left" Height="23" Margin="95,13,0,0" TextWrapping="Wrap" Text="{Binding Path=First_Name, UpdateSourceTrigger=PropertyChanged}"  VerticalAlignment="Top" Width="120" />
        <TextBox HorizontalAlignment="Left" Height="23" Margin="95,47,0,0" TextWrapping="Wrap" Text="{Binding Path=Last_Name, UpdateSourceTrigger=PropertyChanged}" VerticalAlignment="Top" Width="120"/>
        <Label Content="First Name" HorizontalAlignment="Left" Margin="8,10,0,0" VerticalAlignment="Top"/>
        <Label Content="Last Name" HorizontalAlignment="Left" Margin="9,47,0,0" VerticalAlignment="Top" RenderTransformOrigin="0.68,1.974"/>
        <Label Content="DOB" HorizontalAlignment="Left" Margin="8,75,0,0" VerticalAlignment="Top" RenderTransformOrigin="0.68,1.974"/>
        <DatePicker Height="25" HorizontalAlignment="Left" Margin="95,76,0,0" Name="datePicker1"
            VerticalAlignment="Top" Width="120" SelectedDate="{Binding Path=DOB, UpdateSourceTrigger=PropertyChanged}"/>
        <Button Content="Add" HorizontalAlignment="Left" Margin="9,118,0,0" VerticalAlignment="Top" Width="75" Command="{Binding Path=AddCommand}"/>
        <Button Content="Update" HorizontalAlignment="Left" Margin="102,118,0,0" VerticalAlignment="Top" Width="75"/>
        <Button Content="Delete" HorizontalAlignment="Left" Margin="193,118,0,0" VerticalAlignment="Top" Width="75"/>
        <ListView BorderBrush="White" ItemsSource="{Binding Path=ContactsList, UpdateSourceTrigger=PropertyChanged}"
                   HorizontalAlignment="Stretch" Margin="11,156,10,10" SelectedValue="{Binding Path=Contacts, UpdateSourceTrigger=PropertyChanged}">
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="First Name" 
                                    DisplayMemberBinding="{Binding Path=First_Name}" Width="70" />
                    <GridViewColumn Header="Last Name"
                                    DisplayMemberBinding="{Binding Path=Last_Name}" Width="70" />
                    <GridViewColumn Header="DOB" 
                                    DisplayMemberBinding="{Binding Path=DOB}" Width="70" />

                </GridView>
            </ListView.View>
        </ListView >

    </Grid>
</Window>

如果可能的话，请指导并给我任何带有 sql crud 函数的实际应用程序的参考，我可以从中提高我的技能。

谢谢

4

2 回答 2

0

DataTable 没有实现 INotifyPropertyChanged，因此直接绑定到它会有问题。您将看到初始数据，但随后对数据的更改将不会反映在视图中。

我想说最简单的替代方法是使用 DataView，它确实实现了 INotifyPropertyChanged。您可以使用_tblContacts.DefaultView.

于 2013-10-07T17:42:15.790 回答
0

@Rob H，我稍微改变了我的逻辑，我想现在我正在获取我的值和记录，但现在唯一的问题是 gridview 在插入记录后没有刷新。

请查看下面的代码。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows.Input;
using DatabaseLayer;
using System.Data;

namespace WPFnMVVM.ViewModel 
{
    public class ContactsViewModel : WPFnMVVM.Common.VMBase
    {
        #region Variables
        private int _Id;
        private string _First_Name;
        private string _Last_Name;
        private DateTime _DOB;
        private clstbl_Contacts _Contacts;
        public WPFnMVVM.Common.RelayCommand _addCommand;
        public ObservableCollection<clstbl_Contacts> _ContactsList;
        #endregion

        #region Contructor
        public ContactsViewModel()
        {
            LoadContacts();
        }      
        #endregion

        #region Public Properties
        public int Id
        {
            get { return _Id; }
            set { _Id = value; OnPropertyChanged("Id"); }
        }
        public string First_Name
        {
            get { return _First_Name; }
            set { _First_Name = value;

                OnPropertyChanged("First_Name"); }
        }
        public string Last_Name
        {
            get { return _Last_Name; }
            set { _Last_Name = value; OnPropertyChanged("Last_Name"); }
        }
        public DateTime DOB
        {
            get { return _DOB; }
            set { _DOB = value; OnPropertyChanged("DOB"); }
        }
        public clstbl_Contacts Contacts
        {
            get { return _Contacts; }
            set
            {
                _Contacts = value;

                OnPropertyChanged("Contacts");
                GetValuesFromModel();
            }


        }
        public ObservableCollection<clstbl_Contacts> ContactsList
        {
            get { return _ContactsList; }
            set
            {
                _ContactsList = value;
                OnPropertyChanged("ContactsList");
            }
        }     
        #endregion

        #region Methods
        private void LoadContacts()
        {

            clstbl_Contacts objContact = new clstbl_Contacts(WPFnMVVM.Common.clsSettings.ConStr);
            DataTable dt = objContact.Select();
            _ContactsList = new ObservableCollection<clstbl_Contacts>();

            for (int i = 0; i < dt.Rows.Count; i++)
            {
                _ContactsList.Add(new clstbl_Contacts { Id = Convert.ToInt16(dt.Rows[i]["ID"].ToString())
                                                        ,First_Name = dt.Rows[i]["First_Name"].ToString(),
                                                        Last_Name = dt.Rows[i]["Last_Name"].ToString(),
                                                        DOB = Convert.ToDateTime(dt.Rows[i]["DOB"].ToString())
                });
            }

        }
        private void AddContacts()
        {
            clstbl_Contacts objContacts = new clstbl_Contacts(WPFnMVVM.Common.clsSettings.ConStr);
            objContacts.First_Name = First_Name;
            objContacts.Last_Name = Last_Name;
            objContacts.DOB = DOB;
            objContacts.Insert();

        }

        private void GetValuesFromModel()
        {
            Id = _Contacts.Id;
            First_Name = _Contacts.First_Name;
            Last_Name = _Contacts.Last_Name;
            DOB = _Contacts.DOB;
        }
        #endregion

        #region Commands
          public ICommand AddCommand
        {
            get
            {
                if (_addCommand == null)
                {
                    _addCommand = new WPFnMVVM.Common.RelayCommand(
                        param => this.AddContacts(),
                        param => true
                        );
                }
                return _addCommand;
            }
        }
        #endregion

    }
}

看法

<Window x:Class="WPFnMVVM.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:VM="clr-namespace:WPFnMVVM.ViewModel"
        xmlns:View="clr-namespace:WPFnMVVM"

        Title="MainWindow" Height="350" Width="337">
    <Window.DataContext>
        <VM:ContactsViewModel/>
    </Window.DataContext>
    <Grid Name="MyGrid">
        <TextBox HorizontalAlignment="Left" Height="23" Margin="95,13,0,0" TextWrapping="Wrap" 
                 Text="{Binding Path=First_Name, UpdateSourceTrigger=PropertyChanged}"   VerticalAlignment="Top" Width="120" />

        <TextBox HorizontalAlignment="Left" Height="23" Margin="95,47,0,0" TextWrapping="Wrap" Text="{Binding Path=Last_Name, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" VerticalAlignment="Top" Width="120"/>
        <Label Content="First Name" HorizontalAlignment="Left" Margin="8,10,0,0" VerticalAlignment="Top"/>
        <Label Content="Last Name" HorizontalAlignment="Left" Margin="9,47,0,0" VerticalAlignment="Top" RenderTransformOrigin="0.68,1.974"/>
        <Label Content="DOB" HorizontalAlignment="Left" Margin="8,75,0,0" VerticalAlignment="Top" RenderTransformOrigin="0.68,1.974"/>
        <DatePicker Height="25" HorizontalAlignment="Left" Margin="95,76,0,0" Name="datePicker1"
            VerticalAlignment="Top" Width="120" SelectedDate="{Binding Path=DOB, UpdateSourceTrigger=PropertyChanged}"/>
        <Button Content="Add" HorizontalAlignment="Left" Margin="9,118,0,0" VerticalAlignment="Top" Width="75" Command="{Binding Path=AddCommand}"/>
        <Button Content="Update" HorizontalAlignment="Left" Margin="102,118,0,0" VerticalAlignment="Top" Width="75"/>
        <Button Content="Delete" HorizontalAlignment="Left" Margin="193,118,0,0" VerticalAlignment="Top" Width="75"/>
        <ListView BorderBrush="White" ItemsSource="{Binding Path=ContactsList, UpdateSourceTrigger=PropertyChanged}"
                   HorizontalAlignment="Stretch" Margin="11,156,10,10" SelectedValue="{Binding Path=Contacts, UpdateSourceTrigger=PropertyChanged}">
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="First Name" 
                                    DisplayMemberBinding="{Binding Path=First_Name}" Width="70" />
                    <GridViewColumn Header="Last Name"
                                    DisplayMemberBinding="{Binding Path=Last_Name}" Width="70" />
                    <GridViewColumn Header="DOB" 
                                    DisplayMemberBinding="{Binding Path=DOB}" Width="70" />

                </GridView>
            </ListView.View>
        </ListView >

    </Grid>
</Window>
于 2013-10-09T12:15:35.887 回答