WPF刷新界面之坎坷路
项目需要一个硬件检测功能,需要用到界面刷新,刚开始想用个定时器,对检测过的硬设定时添加后刷新界面。
但是很遗憾,定时器并不能进行刷新。后台检测List数据里面已经添加了很多了很多数据了,就是不能显示到界面
然后百度一下“WPF刷新界面”找了好几篇文章,大致都是如下代码:
public class UIHelper : Application
{
//刷新界面
private static DispatcherOperationCallback
exitFrameCallback = new DispatcherOperationCallback(ExitFrame);
public static void DoEvents()
{
DispatcherFrame nestedFrame = new DispatcherFrame();
DispatcherOperation exitOperation =
Dispatcher.CurrentDispatcher.BeginInvoke(
DispatcherPriority.Background,
exitFrameCallback, nestedFrame);
Dispatcher.PushFrame(nestedFrame); if (exitOperation.Status != DispatcherOperationStatus.Completed)
{
exitOperation.Abort();
}
}
private static object ExitFrame(object state)
{
DispatcherFrame frame = state as DispatcherFrame;
frame.Continue = false;
return null;
}
}
我把代码手敲下来,(注意不是复制,应为我不是太懂,这里也劝大家不要轻易复制,因为复制就算解决问题
了下次你还是不知道怎么回事)。在我添加数据后面调用UIHelper .DoEvents(),但是还是没有反应。依然不
刷新,我就郁闷了,别人可以解决为啥到我这就不能用了呢,请教各位大神,这个怎么用啊?有什么前提条件
吗?请我告诉我……
然后继续找啊找啊,在****上找到了类似的问题。原来list<T>没有数据更新的功能,这里面需要用
ObservableCollection<T> 类 或 BindingList<T> 类 代替 List 类,看ObservableCollection<T>在帮助文档里的说明,
这个提供自动更新数据的接口,可以自动向控件发送更新消息,果断一实验。OK成功显示。
public partial class Window2 : Window
{
DispatcherTimer _mainTimer;
public Window2()
{
InitializeComponent();
_mainTimer = new DispatcherTimer();
_mainTimer.Interval = TimeSpan.FromSeconds(1);
_mainTimer.Tick += new EventHandler(_mainTimer_Tick);
_mainTimer.IsEnabled = true;
} void _mainTimer_Tick(object sender, EventArgs e)
{
if (progressBar1.Value == progressBar1.Maximum)
progressBar1.Value = 0; progressBar1.Value++;
DeviceCheckInfo device = new DeviceCheckInfo();
device.CheckResult = true;
device.Name = "发卡器" + progressBar1.Value;
device.CheckContent = "打卡短短"; Dispatcher.BeginInvoke(new Action(() => {
if (list != null)
list.Add(device);
lbtest.ItemsSource = list;
// UIHelper.DoEvents();
})); }
ObservableCollection<DeviceCheckInfo> list;
private void Window_Loaded(object sender, RoutedEventArgs e)
{ list = new ObservableCollection<DeviceCheckInfo>(){
new DeviceCheckInfo {Name="三合一读卡器",CheckContent="duankou",CheckResult=true },
new DeviceCheckInfo {Name="发卡器",CheckContent="tongdao",CheckResult=false },
new DeviceCheckInfo {Name="打印机",CheckContent="youzhi" ,CheckResult=true}
};
lbtest.ItemsSource = list; } private void button1_Click(object sender, RoutedEventArgs e)
{
DeviceCheckInfo device = new DeviceCheckInfo();
device.CheckResult = true;
device.Name = "发卡器" + progressBar1.Value;
device.CheckContent = "打卡短短";
list.Add(device);
lbtest.ItemsSource = list;
} }
效果如下:
分类: WPF