我想在一定的时间间隔后自动刷新数据网格。我使用的是MVVM模型。
namespace AutoRefresh3.Model
{
public class EmployeeDetails
{
private string name;
private string location;
private double salary;
[System.Xml.Serialization.XmlElementAttribute("Name")]
public string Name
{
get
{
return name;
}
set
{
this.name = value;
NotifyPropertyChanged("Name");
}
}
[System.Xml.Serialization.XmlElementAttribute("Location")]
public string Location
{
get
{
return location;
}
set
{
this.location = value;
NotifyPropertyChanged("Location");
}
}
[System.Xml.Serialization.XmlElementAttribute("Salary")]
public double Salary
{
get
{
return salary;
}
set
{
this.salary = value;
NotifyPropertyChanged("Salary");
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(String propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
namespace AutoRefresh3.ViewModel
{
class EmployeeViewModel
{
private ObservableCollection<EmployeeDetails> empdetails = new ObservableCollection<EmployeeDetails>();
[System.Xml.Serialization.XmlElementAttribute("EmpDetails")]
public ObservableCollection<EmployeeDetails> EmpDetails
{
get
{
return empdetails;
}
set
{
value = empdetails;
NotifyPropertyChanged("EmpDetails");
}
}
public void LoadEmployees()
{
XmlSerializer deserializer = new XmlSerializer(typeof(EmployeeDetails));
TextReader reader = new StreamReader(@"C:\xlf\employeedetails1.xml");
object obj = deserializer.Deserialize(reader);
EmployeeDetails ed = (EmployeeDetails)obj;
empdetails.Add(ed);
//EMPDetails empdetails = (EMPDetails)obj;
//employees.Add(emp);
//employees = (EmployeeDetails)empdetails;
}
public void setTimer()
{
DispatcherTimer timer = new DispatcherTimer();
timer.Interval = TimeSpan.FromMilliseconds(5000);
timer.Tick += Timer_Tick;
timer.Start();
}
private void Timer_Tick(object sender, System.EventArgs e)
{
LoadEmployees();
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(String propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
<Window x:Class="AutoRefresh3.View.view"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="view" Height="300" Width="300">
<Grid>
<DataGrid HorizontalAlignment="Left" x:Name="datagrid1" AutoGenerateColumns="False"
ItemsSource="{Binding EmpDetails}"
Height="600" Margin="24,79,0,0" VerticalAlignment="Top" Width="600">
<DataGrid.Columns>
<DataGridTextColumn Header="Employee Name" Binding="{Binding Name}" />
<DataGridTextColumn Header="Employee Location" Binding="{Binding Location}"/>
<DataGridTextColumn Header="Employee Salary" Binding="{Binding Salary}"/>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Window>
namespace AutoRefresh3.View
{
/// <summary>
/// Interaction logic for view.xaml
/// </summary>
public partial class view : Window
{
public view()
{
InitializeComponent();
EmployeeViewModel ed = new EmployeeViewModel();
this.DataContext = ed;
ed.LoadEmployees();
ed.setTimer();
}
}
}
<?xml version="1.0" ?>
<EmployeeDetails>
<Name>abc</Name>
<Location>Bangalore</Location>
<Salary>1000000</Salary>
<Name>def</Name>
<Location>Mysore</Location>
<Salary>2000000</Salary>
<Name>ghi</Name>
<Location>USA</Location>
<Salary>50000</Salary>
</EmployeeDetails>
上述项目只能在数据网格中显示第一个员工信息，并且每5秒刷新一次，并且只显示第一个记录。我希望每隔5秒以xml显示所有数据。如何实现这一目标？需要做哪些改变？
答案 0 :(得分：1)
我希望这是你正在寻找的行为。
使用可观察的集合（如ObservableCollection）非常重要，否则View永远不会知道任何变化。
此应用程序每秒生成新数据。这些更改立即显示在DataGrid中。
代码背后
public class Employee
{
public string Name { get; set; }
public int Age { get; set; }
}
public partial class MainWindow : Window
{
public ObservableCollection<Employee> Employees { get; set; }
public MainWindow()
{
InitializeComponent();
Employees = new ObservableCollection<Employee>();
datagrid1.DataContext = this;
DispatcherTimer timer = new DispatcherTimer();
timer.Interval = TimeSpan.FromMilliseconds(200);
timer.Tick += Timer_Tick;
timer.Start();
}
private void Timer_Tick(object sender, System.EventArgs e)
{
Employees.Add(new Employee
{
Name = "Name",
Age = (new Random()).Next(0, 100)
});
}
}
<强> XAML
<DataGrid HorizontalAlignment="Left" x:Name="datagrid1"
AutoGenerateColumns="False" ItemsSource="{Binding Employees}">
<DataGrid.Columns>
<DataGridTemplateColumn Header="Name">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}"></TextBlock>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Age">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Age}"></TextBlock>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
答案 1 :(得分：0)
您应该启用PropertyChanged。我假设你已经绑定了要查看的itemsField。我相信你的刷新工作正常。它只是没有反映出视野中的变化。
Object_Type itemsField {
set {
this._itemsField = value;
onPropertyChanged("itemsField");
}
get{
return this._itemsField;
}
}
void OnPropertyChanged(string prop)
{
if (this.PropertyChanged != null)
this.PropertyChanged(this, new PropertyChangedEventArgs(prop));
}
public event PropertyChangedEventHandler PropertyChanged;