网格视图更改事件未触发以及如何在插入记录后刷新网格
本文关键字:网格 插入 刷新 记录 视图 事件 | 更新日期: 2023-09-27 18:33:55
我试图使用 MVVM 模式获得 WPF 上的技能。 我几乎完成了具有基本功能的表单,但面临 2 个问题
1) 我的网格视图更改事件未触发2)插入记录后如何刷新网格
下面给出了我的视图模型和视图代码
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
}
}
视图
<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函数的实际应用的参考,我可以从中提高我的技能。
谢谢
DataTable 不实现 INotifyPropertyChanged,因此您将遇到直接绑定到它的问题。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。
我想说最简单的选择是使用DataView,它确实实现了INotifyPropertyChanged。您可以使用 _tblContacts.DefaultView
轻松获取表的视图。
@Rob H ,我稍微改变了我的逻辑,一个很好的想法是现在我正在获取我的值并插入记录,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
}
}
视图
<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>