使用backgroundworker更新datagrid WPF
问题描述:
datagrid在foreach循环中未更新。在下面的代码中,datagrid在线程完成后更新,但不在之间。因为我的foreach循环是另一个类。我知道,不知何故我必须实现BackgroundWorker.OnProgressChanged方法来更新进度,但无法弄清楚。使用backgroundworker更新datagrid WPF
XMAL FILE
<dg:DataGrid ItemsSource="{Binding}">
<dg:DataGrid.Columns>
<dg:DataGridTextColumn Binding="{Binding grade, Mode=TwoWay, IsAsync=True}" Header="Status"/>
</dg:DataGrid.Columns>
</dg:DataGrid>
GUI CLASS
public partial class GUIClass : Page
{
BackgroundWorker bgWorker = new BackgroundWorker();
public GUIClass()
{
InitializeComponent();
bgWorker.WorkerSupportsCancellation = true;
bgWorker.WorkerReportsProgress = true;
}
private void btnOK_Click(object sender, RoutedEventArgs e)
{
bgWorker.DoWork += new DoWorkEventHandler(bgWorker_DoWork);
bgWorker.ProgressChanged += new ProgressChangedEventHandler(bgWorker_ProgressChanged);
bgWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bgWorker_RunWorkerCompleted);
bgWorker.RunWorkerAsync();
}
void bgWorker_DoWork(object sender, DoWorkEventArgs e)
{
ClassA cls= new ClassA();
cls.runprocess();
}
void bgWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
dataGrid1.Items.Refresh();
}
void bgWorker_RunWorkerCompleted(object sender,RunWorkerCompletedEventArgs e)
{
....
.....
dataGrid1.Items.Refresh();
}
}
数据网格绑定
类public class BindClass
{
public bool staus{ set; get; }
public string grade{ set; get; }
}
ClassA的
class ClassA
{
public void runprocess()
{
foreach (var item in IEnumerable<BindClass>)
{
if(somecondition)
{
// I want to update datagrid at this stage so user can see it
item.grade="First"
}
}
}
}
答
为了在更改类的'grade'属性时更新数据网格,它需要实现INotifyPropertyChanged。尝试更新类,如下所示:
public class BindClass : INotifyPropertyChanged
{
private string _grade;
public string Grade
{
get { return _grade; }
set
{
if (_grade == value)
return;
_grade = value;
OnPropertyChanged("Grade");
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected void OnPropertyChanged(string property)
{
if (PropertyChanged!=null)
{
PropertyChanged(this, new PropertyChangedEventArgs(property));
}
}
}
注意 - 我已经从“品位”到“级”更改属性的名称遵循.NET约定。我相信你可以添加状态属性自己的执行;-)
答
我会去一个解决方案,DataGrid的ItemsSource时是ObservableCollection
,使事情变得更容易,而且我认为你可以做到这一点,你的情况从你写的是什么。
这样你就不必去执行INotifyPropertyChanged的事件处理程序
的麻烦(注:ObservableCollections修改更新UI,而其他集合类型不)。这是MS建议在dataGrid的文档中做的事情(虽然我不能把我的手放在我读过的文档的位上)