那些遇到过的问题

Datagrid selectedItem和数据绑定

Ind*_*dhi 5 c# wpf xaml wpf-controls wpfdatagrid

我的UI上显示了两个数据网格.当我在datagrid 1上选择一个特定的行时,我想在datagrid 2上显示datagrid 1的详细信息.我正在从数据库中填充datagrid数据.这是两个数据库表结构.

注意:表都由数据库中的personid映射

人员表

PersonDetails表

这是迄今为止我尝试过的代码

Baseclass.cs

public class Baseclass
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected void SetProperty<T>(ref T member, T value, [CallerMemberName] string propertyName = null)
    {
        member = value;
        this.RaiseNotification(propertyName);
    }

    protected void RaiseNotification(string propertyName)
    {
        if (this.PropertyChanged != null)
        {
            this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}
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person.cs

public class person : Baseclass
{

    private int personID;
    public int PersonID
    {
        get { return personID; }
        set { this.SetProperty<int>(ref this.personID, value); }
    }

    private string firstName;
    public string FirstName
    {
        get { return firstName; }
        set { this.SetProperty<string>(ref this.firstName, value); }
    }

    private string lastName;
    public string LastName
    {
        get { return lastName; }
        set { this.SetProperty<string>(ref this.lastName, value); }
    }

    Model _personModel = new Model();
    private ObservableCollection<person> _person = new ObservableCollection<person>();
    public ObservableCollection<person> Getpersons
    {
        get { return _person; }
        set { _person = value; OnPropertyChanged("GetPersons"); }
    }

    public person()
    {
        initializeload();
    }

    private void initializeload()
    {
        try
        {
            DataTable table = _personModel.getData();

            for (int i = 0; i < table.Rows.Count; ++i)
                Getpersons.Add(new person
                {
                 PersonID = Convert.ToInt32(table.Rows[i][0]),
                 FirstName = table.Rows[i][1].ToString(),
                 LastName = table.Rows[i][2].ToString(),
                });
        }

        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }
    public event PropertyChangedEventHandler PropertyChanged;

    private void OnPropertyChanged(string propertyname)
    {
        var handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyname));
    }

    public class Model
    {
        public DataTable getData()
        {
            DataTable ndt = new DataTable();
            SqlConnection sqlcon = new SqlConnection(ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString);
            sqlcon.Open();
            SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM [Person].[dbo].[persons]", sqlcon);
            da.Fill(ndt);
            da.Dispose();
            sqlcon.Close();
            return ndt;
        }
    }

}
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PersonDetail类

public  class PersonDetails : Baseclass
{
    private int personID;
    public int PersonID
    {
        get { return personID; }
        set { this.SetProperty<int>(ref this.personID, value); }
    }

    private string address;
    public string Address
    {
        get { return address; }
        set { this.SetProperty<string>(ref this.address, value); }
    }

    private string pos;
    public string Position
    {
        get { return pos; }
        set { this.SetProperty<string>(ref this.pos, value); }
    }

    DetailsModel _detailModel = new DetailsModel();
    private ObservableCollection<PersonDetails> _details = new ObservableCollection<PersonDetails>();
    public ObservableCollection<PersonDetails> GetDetails
    {
        get { return _details; }
        set { _details = value; OnPropertyChanged("GetDetails"); }
    }
    public event PropertyChangedEventHandler PropertyChanged;

    private void OnPropertyChanged(string propertyname)
    {
        var handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyname));
    }

    public PersonDetails()
    {
        initializeload();
    }

    private void initializeload()
    {
        try
        {
            DataTable table = _detailModel.getData();

            for (int i = 0; i < table.Rows.Count; ++i)
                GetDetails.Add(new PersonDetails
                {
                    PersonID = Convert.ToInt32(table.Rows[i][0]),
                    Address = table.Rows[i][1].ToString(),
                    Position = table.Rows[i][2].ToString(),                        
                });
        }

        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }
    public class DetailsModel
    {
        public DataTable getData()
        {
            DataTable ndt = new DataTable();
            SqlConnection sqlcon = new SqlConnection(ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString);
            sqlcon.Open();
            SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM [Person].[dbo].[personDetails]", sqlcon);
            da.Fill(ndt);
            da.Dispose();
            sqlcon.Close();
            return ndt;
        }
    }
}
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MainViewModel.cs

    public class MainViewModel : Base, INotifyPropertyChanged
{
    public MainViewModel()
    {
    }

    private ObservableCollection<person> personValues;
    public ObservableCollection<person> Persons
    {
        get { return personValues; }
        set
        {
            this.SetProperty<ObservableCollection<person>>(ref this.personValues, value);
        }
    }

    private ObservableCollection<PersonDetails> detailsValues;
    public ObservableCollection<PersonDetails> Details
    {
        /* This is correct below ?? I have an error as 
        'PersonDemo.MainViewModel' does not contain a definition for 'GetDetails' and no extension method 'GetDetails' accepting a first argument of type 'PersonDemo.MainViewModel' could be found (are you missing a using directive or an assembly reference?)*/
        get { return this.GetDetails(this.Selectedperson.PersonID); }
    }

    private person selectedValue;
    public person Selectedperson
    {
        get { return selectedValue; }
        set
        {
            this.SetProperty<person>(ref this.selectedValue, value);
            this.RaiseNotification("Details");
        }
    }


}
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XAML

  <Grid>
  <DataGrid Margin="100,20,116,211" ItemsSource="{Binding Persons}" SelectedItem="{Binding Selectedperson}"  />
  <DataGrid Margin="100,130,116,101" ItemsSource="{Binding Details}" />
  </Grid>
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有人可以帮忙继续编写MainViewModel吗？我好几周都被困在这里.

Raú*_*año 7

首先,我建议使用INotifyPropertyChanged基类中的接口.也许您使用它并忘记在示例代码中写入它.为了使用MVVM模式,您需要为两个数据网格实现ViewModel.我们在我们的示例中调用它BothGridViewModel,您可以根据需要调用它.然后在这个视图模型中你需要所有人的集合,让我们调用它AllPerson,然后你需要有一个Person类型的属性,当你在网格中有所选的人时,让我们调用它SelectedPerson.它将是这样的:

public class BothGridViewModel:INotifyPropertyChanged
{
    ...
    public ObservableCollection<Person> AllPersons {...}
    public Person SelectedPerson {...}
    ...
}
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您只需要在View的DataContext中设置它.和绑定:

<YourView DataContext={Binding SomeBothGridViewModelClass}>
    <Grid>
     <DataGrid Margin="100,20,116,211" ItemsSource="{Binding AllPersons}" SelectedItem="{Binding SelectedPerson}"  />
     <DataGrid Margin="100,130,116,101" ItemsSource="{Binding SelectedPerson.Getpersons}" /> <!--Or some SelectedPerson.PersonDetails.GetDetails-->
  </Grid>
</YourView DataContext={Binding SomeBothGridViewModelClass}>
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我认为这是制作你想要的好视图模型结构.希望这可以帮助你......

编辑

我现在看到你的观点,你有两个数据库表,一个用于主要属性,另一个用于详细信息.我看到了两个很好的方法:1)第一个,我不相信第二个数据网格是必要的,因为每个人都没有一些细节.相反,您可以使用网格和其他控件来显示属性.另外我认为你必须为这个人实现一个视图模型,例如:

public class PersonViewModel:INotifyPropertyChanged
{
     public string FirstName {...}
     public string LastName {...}
     //Other properties

     public PersonDetails Details {...}
}
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然后在网格中,您可以将项目源绑定到一个集合,PersonViewModel然后您可以绑定到网格的选定项目,例如:

<Grid>
    <DataGrid x:Name="dataGrid" ItemsSource={Binding AllPersonViewModels}/>
    ...
    <!--Then some combo box, text block or text box binding to a property of the selected item's details-->
          ...
          <TextBox Text={Binding SelectedItem.Details.Address, ElementName=dataGrid}/>
          ...
<Grid>
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2)我认为可以做的第二种方式是在同一个数据网格中显示所有数据.为此,您需要以PersonViewModel这种方式完成课程:

public class PersonViewModel:INotifyPropertyChanged
{
     public string FirstName {...}
     public string LastName {...}
     //Other properties

     //Then the Details properties
     public string Address {...}
     //...
     //Note this class is like a wrapper for person, and person details
}
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这种方式稍微简单一些,但可能导致不需要的数据库访问.

编辑2

看看你的代码之后,我不得不说一些关于它的事情:在PersonViewModel和PersonDetailViewModel你应该使用a DispatcherTimer而不是a Timer,因为我们在Wpf中.其他的事情,也许你应该使用一个Repository模式来创建一个PersonRepository和一个PersonDetailRepository放置所有数据库通信的地方,事实上,PersonViewModel并且PersonDetailViewModel在某种程度上是存储库,但是现在你不需要改变它,它应该工作.我将在这里向您展示代码MainViewModel,我将其修改为具有SelectedPersonDetail属性,这样,您需要做的就是在视图中进行绑定:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using tryout13022013.PersonViewModels;
using System.ComponentModel;
using tryout13022013.DetailsViewModel;
using tryout13022013.PersonModel;

namespace tryout13022013
{
    public class MainViewModel
    {
        private PersonViewModel _subPerson = new PersonViewModel();
        public PersonViewModel SubPerson
        {
            get 
            {
                return _subPerson;
            }
            set
            {
                if (_subPerson != value)
                {
                    _subPerson = value; OnPropertyChanged("SubPerson");

                }
            }
        }


        private PersonDetailsViewModel _subDetail = new PersonDetailsViewModel();
        public PersonDetailsViewModel SubDetail
        {
            get { return _subDetail; }
            set 
            {
                _subDetail = value; OnPropertyChanged("SubDetail");
            }

        }

        private Person _selectedPerson;
        public Person SelectedPerson
        {
            get { return _selectedPerson; }
            set {
                if (_selectedPerson != value)
                {
                    _selectedPerson = value;
                    OnPropertyChanged("SelectedPerson");
                    OnPropertyChanged("SelectedPersonDetail");  //In this way when Change the Selected Person, the Selected Detail will be changed again...
                    //if (this.SelectedPerson != null && this.SubDetail != null)
                    //{
                       // I dont know how to call the PersonDetailsViewModel class like a method here in order to load its data. kindly help
                       //this.SubDetail.MethodforLoadingPersonDetails(this.SelectedPerson);
                    //}
                }
            }

        }

        public PersonDetails SelectedPersonDetail
        {
            get
            {
                if (SubDetail == null || SelectedPerson ==null)
                    return  null;
                return SubDetails.DetailsData.FirstOrDefault(detail => detail.PersonID == SelectedPerson.PersonID);
            }           

        }


        public event PropertyChangedEventHandler PropertyChanged;

        private void OnPropertyChanged(string propertyname)
        {
            var handler = PropertyChanged;
            if (handler != null)
                handler(this, new PropertyChangedEventArgs(propertyname));
        }
    }
}
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这是您可以在视图中进行绑定的实例,在这种情况下,用于选择第二个网格中的项目:

<Window x:Class="tryout13022013.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:person="clr-namespace:tryout13022013.PersonViewModels"
    xmlns:details="clr-namespace:tryout13022013.DetailsViewModel"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <DataGrid ItemsSource="{Binding SubPerson.PersonData}"  SelectedItem="{Binding SelectedPerson, Mode=TwoWay}"
        AutoGenerateColumns="False" Height="77" HorizontalAlignment="Left"
        Margin="101,26,0,0" Name="dataGrid1" VerticalAlignment="Top" Width="auto" >
        <DataGrid.DataContext>
            <person:PersonViewModel/>
        </DataGrid.DataContext>
        <DataGrid.Columns>
            <DataGridTextColumn Header="ID" Width="auto" Binding="{Binding PersonID}"/>
            <DataGridTextColumn Header="First Name" Width="auto" Binding="{Binding FirstName}"/>
            <DataGridTextColumn Header="Last Name" Width="auto" Binding="{Binding LastName}"/>     
        </DataGrid.Columns>
    </DataGrid>


    <DataGrid ItemsSource="{Binding SubDetail.DetailsData}" 
        AutoGenerateColumns="False" Height="77" HorizontalAlignment="Left" 
        Margin="101,135,0,0" Name="dataGrid2" VerticalAlignment="Top" Width="255" SelectedItem="{Binding SelectedPersonDetail, Mode=OneWayToSource}">
        <DataGrid.DataContext>
            <details:PersonDetailsViewModel/>
        </DataGrid.DataContext>
        <DataGrid.Columns>
            <DataGridTextColumn Header="ID" Width="auto" Binding="{Binding PersonID}"/>
            <DataGridTextColumn Header="Address" Width="auto" Binding="{Binding Address}"/>
            <DataGridTextColumn Header="Position" Width="auto" Binding="{Binding Description}"/>
        </DataGrid.Columns>
    </DataGrid>
</Grid>
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我忘了,你需要做的约束力SubPerson.PersonData和SubDetail.DetailsData,这些都是收藏.看看这个...

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