Windows phone 7 BackgroundWorker用户界面没有'；t更新Windows Phone 7中的进度
在WindowsPhone7中，我试图显示一些LINQ查询的状态。 我在用BackgroundWorker。我在调试窗口中看到进度更新，但在UI（TextBlock4.Text）中看不到。所有查询结束后，进度似乎会更新。此外，UI在运行查询时没有响应。如何避免UI冻结？如何在UI中显示进度？是否有其他方式显示查询进度Windows phone 7 BackgroundWorker用户界面没有'；t更新Windows Phone 7中的进度,windows-phone-7,backgroundworker,Windows Phone 7,Backgroundworker,在WindowsPhone7中，我试图显示一些LINQ查询的状态。 我在用BackgroundWorker。我在调试窗口中看到进度更新，但在UI（TextBlock4.Text）中看不到。所有查询结束后，进度似乎会更新。此外，UI在运行查询时没有响应。如何避免UI冻结？如何在UI中显示进度？是否有其他方式显示查询进度 Partial Public Class pagInvoicesReport Inherits PhoneApplicationPage Private WithEvents m
Partial Public Class pagInvoicesReport
Inherits PhoneApplicationPage
Private WithEvents mWorker As New BackgroundWorker()
Private nJan As Nullable(Of Decimal) = 0
Private nFeb As Nullable(Of Decimal) = 0
Private nMar As Nullable(Of Decimal) = 0
Private nApr As Nullable(Of Decimal) = 0
Private nMay As Nullable(Of Decimal) = 0
Private nJun As Nullable(Of Decimal) = 0
Private nJul As Nullable(Of Decimal) = 0
Private nAug As Nullable(Of Decimal) = 0
Private nSept As Nullable(Of Decimal) = 0
Private nOct As Nullable(Of Decimal) = 0
Private nNov As Nullable(Of Decimal) = 0
Private nDec As Nullable(Of Decimal) = 0
Public Sub New()
InitializeComponent()
mWorker.WorkerReportsProgress = True
End Sub
Private Sub startButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles startButton.Click
mWorker.RunWorkerAsync()
End Sub
Private Sub mWorker_ProgressChanged(ByVal sender As Object, ByVal e As ProgressChangedEventArgs) Handles mWorker_ProgressChanged
TextBlock4.Text = e.ProgressPercentage.ToString() & "%"
System.Diagnostics.Debug.WriteLine(e.ProgressPercentage.ToString() & "%")
End Sub
Private Sub GetGraphValues() Handles mWorker.DoWork
System.Windows.Deployment.Current.Dispatcher.BeginInvoke( _
Sub()
Using theDB As New appContext("Data Source=isostore:/theDB.sdf")
Try
If (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 1 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?))) IsNot Nothing Then
nJan = (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 1 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?)))
Else
nJan = 0
End If
Catch ex As Exception
MessageBox.Show("There was an error!" & vbCrLf & ex.Message, "Error!", MessageBoxButton.OK)
End Try
End Using
End Sub)
mWorker.ReportProgress(8)
System.Windows.Deployment.Current.Dispatcher.BeginInvoke( _
Sub()
Using theDB As New appContext("Data Source=isostore:/theDB.sdf")
Try
If (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 2 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?))) IsNot Nothing Then
nFeb = (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 2 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?)))
Else
nFeb = 0
End If
Catch ex As Exception
MessageBox.Show("There was an error!" & vbCrLf & ex.Message, "Error!", MessageBoxButton.OK)
End Try
End Using
End Sub)
mWorker.ReportProgress(17)
System.Windows.Deployment.Current.Dispatcher.BeginInvoke( _
Sub()
Using theDB As New appContext("Data Source=isostore:/theDB.sdf")
Try
If (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 12 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?))) IsNot Nothing Then
nDec = (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 12 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?)))
Else
nDec = 0
End If
Catch ex As Exception
MessageBox.Show("There was an error!" & vbCrLf & ex.Message, "Error!", MessageBoxButton.OK)
End Try
End Using
End Sub)
mWorker.ReportProgress(100)
End Sub
End Class看起来您正在发布要在UI线程上完成的工作。您认为DoWork方法不应调用调度程序。这将把所有的工作放在UI线程而不是BackgroundWorker线程上 更新：刚刚注意到您正在访问成员变量。不建议这样做，您的后台工作人员应该返回其计算的结果，下面是一个简单的示例，显示在列表中返回的结果（我不是VB专家，请耐心等待）。工作程序完成后，获取结果并替换属性 尝试将您的DoWork处理程序更改为：
Private Sub GetGraphValues(args as DoWorkEventArgs) Handles mWorker.DoWork
Dim list as List<Decimal>();
Dim jan as Decimal
Dim feb as Decimal
Dim dec as Dicimal
Using theDB As New appContext("Data Source=isostore:/theDB.sdf")
Try
If (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 1 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?))) IsNot Nothing Then
jan = (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 1 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?)))
Else
jan = 0
End If
Catch ex As Exception
' Showing messageBox SHOULD be shown on UI thread
System.Windows.Deployment.Current.Dispatcher.BeginInvoke( _
Sub()
MessageBox.Show("There was an error!" & vbCrLf & ex.Message, "Error!", MessageBoxButton.OK)
End Sub)
End Try
End Using
list.Add(jan);
mWorker.ReportProgress(8)
Using theDB As New appContext("Data Source=isostore:/theDB.sdf")
Try
If (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 2 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?))) IsNot Nothing Then
feb = (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 2 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?)))
Else
feb = 0
End If
Catch ex As Exception
' Showing messageBox SHOULD be shown on UI thread
System.Windows.Deployment.Current.Dispatcher.BeginInvoke( _
Sub()
MessageBox.Show("There was an error!" & vbCrLf & ex.Message, "Error!", MessageBoxButton.OK)
End Sub)
End Try
End Using
list.Add(feb)
mWorker.ReportProgress(17)
Using theDB As New appContext("Data Source=isostore:/theDB.sdf")
Try
If (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 12 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?))) IsNot Nothing Then
dec = (Aggregate r In theDB.InvoicesRecords Where r.InvoiceDateTime.Month = 12 And r.InvoiceDateTime.Year = 2012 And r.MainID = 1 Into Sum(CType(r.Cost, Decimal?)))
Else
dec = 0
End If
Catch ex As Exception
' Showing messageBox SHOULD be shown on UI thread
System.Windows.Deployment.Current.Dispatcher.BeginInvoke( _
Sub()
MessageBox.Show("There was an error!" & vbCrLf & ex.Message, "Error!", MessageBoxButton.OK)
End Sub)
End Try
End Using
list.Add(dec)
mWorker.ReportProgress(100)
args.Result = list
End Sub
Private子GetGraphValue（作为DoWorkEventArgs的参数）处理mWorker.DoWork
将列表设置为列表（）；
十进制
十进制
Dim dec as Dicimal
将DB用作新的appContext（“数据源=isostore:/theDB.sdf”）
尝试
如果（r.InvoiceDateTime.Month=1，r.InvoiceDateTime.Year=2012，r.MainID=1的DB.InvoicesRecords中的r合计为总和（CType（r.Cost，Decimal？）不是零，则
jan=（将b.Invoices记录中的r相加，其中r.InvoicesDateTime.Month=1，r.InvoicesDateTime.Year=2012，r.MainID=1，并将其相加（C类型（r.Cost，十进制？））
其他的
1月=0
如果结束
特例
'显示消息框应显示在UI线程上
System.Windows.Deployment.Current.Dispatcher.BeginInvoke（_
分（）
Show（“出现错误！”&vbCrLf&ex.Message，“error！”，MessageBoxButton.OK）
末端接头）
结束尝试
终端使用
增加（1月）；
mWorker.ReportProgress（8）
将DB用作新的appContext（“数据源=isostore:/theDB.sdf”）
尝试
如果（b.invoices记录中的合计r，其中r.invoicesdatetime.Month=2，r.invoicesdatetime.Year=2012，r.MainID=1）的总和（CType（r.Cost，Decimal？）不是零，则
feb=（将b.invoices记录中的r相加，其中r.invoicesdatetime.Month=2，r.invoicesdatetime.Year=2012，r.MainID=1，并将其相加（CType（r.Cost，Decimal？））
其他的
二月=0
如果结束
特例
'显示消息框应显示在UI线程上
System.Windows.Deployment.Current.Dispatcher.BeginInvoke（_
分（）
Show（“出现错误！”&vbCrLf&ex.Message，“error！”，MessageBoxButton.OK）
末端接头）
结束尝试
终端使用
列表。添加（2月）
mWorker.报告进度（17）
将DB用作新的appContext（“数据源=isostore:/theDB.sdf”）
尝试
如果（r.InvoiceDateTime.Month=12，r.InvoiceDateTime.Year=2012，r.MainID=1的B.InvoicesRecords中的合计r为总和（CType（r.Cost，Decimal？）不是零，则
dec=（将b.InvoicesRecords中的r相加，其中r.InvoicesDateTime.Month=12，r.InvoicesDateTime.Year=2012，r.MainID=1，并将其相加（C类型（r.Cost，十进制？））
其他的
十二月=0
如果结束
特例
'显示消息框应显示在UI线程上
System.Windows.Deployment.Current.Dispatcher.BeginInvoke（_
分（）
Show（“出现错误！”&vbCrLf&ex.Message，“error！”，MessageBoxButton.OK）
末端接头）
结束尝试
终端使用
列表。添加（12月）
mWorker.报告进度（100）
args.Result=list
端接头