我正在尝试使用调度程序更新进度条，但不知何故无法考虑将dispatcher.Invoke放在哪里以及在其中传递的内容。
我试图导入文件，需要向用户显示使用进度条导入的文件数量。
所以我有一个代表：
public delegate void DelegateA(ProgressClass progressClass);
我调用委托并传递函数进行调用。
DelegateA(FunctionA);
因此，在导入每个文件时，它会调用FunctionA。
private void FunctionA(ProgressClass progressClass)
{
**//Put dispatcher.invoke here?**
progressbar.updateprogress(progressclass);
progressbar.show();
}
progressclass有两个属性，用于设置进度条的值（已处理的数量）和要处理的项目总数。
我无法理解在InvokeMethod中传递的委托方法（THreadPriority，委托方法）？
对不起，如果不清楚的话。
答案 0 :(得分：7)
如果您尝试从某些非UI线程更新UI，则可以执行以下操作..
//here progress bar is a UIElement
progressBar.Dispatcher.BeginInvoke(
System.Windows.Threading.DispatcherPriority.Normal
, new DispatcherOperationCallback(delegate
{
progressBar1.Value = progressBar1.Value + 1;
//do what you need to do on UI Thread
return null;
}), null);
此代码取自关于从后台线程更新UI的好post
答案 1 :(得分：2)
我假设您已经启动了后台线程来导入文件。您应该考虑使用BackgroundWorker，它是轻量级的，并且内置了一种机制来报告使用事件的进度（例如，ProgressBar）。
如果要在处理过程中的任何位置使用新线程，只需声明委托，向目标添加函数，然后调用Dispatcher.BeginInvoke：
Dispatcher.BeginInvoke(DispatcherPriority.Normal, new UpdateProgressDelegate(UpdateProgress), myProgressData);
//...
private delegate void UpdateProgressDelegate(ProgressClass progressClass);
void UpdateProgress(ProgressClass progressClass)
{
progressbar.updateprogress(progressclass);
progressbar.show();
}
答案 2 :(得分：0)
以下是带有进度条的CSV阅读器的代码
private void InsertCSVRecords（DataTable csvdt） {
connection();
//creating object of SqlBulkCopy
SqlBulkCopy objbulk = new SqlBulkCopy(con);
//assigning Destination table name
objbulk.DestinationTableName = "membershipsample";
//Mapping Table column
objbulk.ColumnMappings.Add("GPO_NAME", "GPO_NAME");
objbulk.ColumnMappings.Add("Ship_To", "Ship_To");
objbulk.ColumnMappings.Add("Location_Type", "Location_Type");
objbulk.ColumnMappings.Add("Bill_To", "Bill_To");
objbulk.ColumnMappings.Add("GPO_CUST_ID", "GPO_CUST_ID");
objbulk.ColumnMappings.Add("PRI_AFL_FLG", "PRI_AFL_FLG");
objbulk.ColumnMappings.Add("MCK_GPO_PGM_TYPE", "MCK_GPO_PGM_TYPE");
objbulk.ColumnMappings.Add("MCK_GPO_PGM_SUB_TYPE", "MCK_GPO_PGM_SUB_TYPE");
objbulk.ColumnMappings.Add("MCK_MBRSH_EFF_DT", "MCK_MBRSH_EFF_DT");
objbulk.ColumnMappings.Add("CUST_MAILING_NAME", "CUST_MAILING_NAME");
objbulk.ColumnMappings.Add("ADDRESS1", "ADDRESS1");
objbulk.ColumnMappings.Add("ADDRESS2", "ADDRESS2");
objbulk.ColumnMappings.Add("CITY", "CITY");
objbulk.ColumnMappings.Add("STATES", "STATES");
objbulk.ColumnMappings.Add("POSTAL_CODE", "POSTAL_CODE");
objbulk.ColumnMappings.Add("ACCT_MGR_NAME", "ACCT_MGR_NAME");
con.Open();
objbulk.WriteToServer(csvdt);
con.Close();
}
private void button_Click(object sender, RoutedEventArgs e)
{
Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
// Set filter for file extension and default file extension
dlg.DefaultExt = ".csv";
dlg.Filter = "CSV Files (*.cvs)|*.csv|Excel Files (*.xlsx)|*.xlsx";
// dlg.Filter = "JPEG Files (*.jpeg)|*.jpeg|PNG Files (*.png)|*.png|JPG Files (*.jpg)|*.jpg|GIF Files (*.gif)|*.gif";
//dlg.Filter = "CSV Files (*.csv)";
// Display OpenFileDialog by calling ShowDialog method
Nullable<bool> result = dlg.ShowDialog();
// Get the selected file name and display in a TextBox
if (result == true)
{
// Open document
string filename = dlg.FileName;
textBox.Text = filename;
// readCSV(filename);
}
}
private void readCSV(string Path)
{
using (var reader = new StreamReader(Path))
{
List<string> listA = new List<string>();
List<string> listB = new List<string>();
while (!reader.EndOfStream)
{
var line = reader.ReadLine();
var values = line.Split(';');
if (!String.IsNullOrEmpty(values[0]))
listA.Add(values[0]);
if (values.Length > 2 && !String.IsNullOrEmpty(values[1]))
listB.Add(values[1]);
}
}
}
private void Bk_DoWork(object sender, DoWorkEventArgs e)
{
// txtStatus.Visibility = System.Windows.Visibility.Visible;
DispatcherTimer timer = new DispatcherTimer();
//Creating object of datatable
DataTable tblcsv = new DataTable();
//creating columns
tblcsv.Columns.Add("GPO_NAME");
tblcsv.Columns.Add("Ship_To");
tblcsv.Columns.Add("Location_Type");
tblcsv.Columns.Add("Bill_To");
tblcsv.Columns.Add("GPO_CUST_ID");
tblcsv.Columns.Add("PRI_AFL_FLG");
tblcsv.Columns.Add("MCK_GPO_PGM_TYPE");
tblcsv.Columns.Add("MCK_GPO_PGM_SUB_TYPE");
tblcsv.Columns.Add("MCK_MBRSH_EFF_DT");
tblcsv.Columns.Add("CUST_MAILING_NAME");
tblcsv.Columns.Add("ADDRESS1");
tblcsv.Columns.Add("ADDRESS2");
tblcsv.Columns.Add("CITY");
tblcsv.Columns.Add("STATES");
tblcsv.Columns.Add("POSTAL_CODE");
tblcsv.Columns.Add("ACCT_MGR_NAME");
// DispatcherTimer timer = new DispatcherTimer();
string url=string.Empty;
this.Dispatcher.Invoke(() => { url = textBox.Text; });
string ReadCSV = File.ReadAllText(url);
//spliting row after new line url
int i = 0;
DataTable dt = GetMemberTable();
var worker = sender as BackgroundWorker;
int rows = ReadCSV.Split('\n').Length / 100;
int totalRows = ReadCSV.Split('\n').Length;
foreach (string csvRow in ReadCSV.Split('\n'))
{
i++;
// Thread.Sleep(1000);
worker.ReportProgress((i/rows + 1), string.Format("This is new one"));
this.Dispatcher.Invoke(() => { label.Content = i + " rows have been added or updated"; });
bool Check = (csvRow.Length > 0) ? Exist(csvRow.Split(',')[1].ToString(), dt) : true;
if (i > 1 && !string.IsNullOrEmpty(csvRow))
{
//Adding each row into datatable
int count = 0;
if (!Check)
{
tblcsv.Rows.Add();
foreach (string FileRec in csvRow.Split(','))
{
if (count >= 15)
{
tblcsv.Rows[tblcsv.Rows.Count - 1][count] = FileRec;
}
else
{
tblcsv.Rows[tblcsv.Rows.Count - 1][count] = FileRec;
count++;
}
// //Calling insert Functions
// Dispatcher.Invoke(
//new System.Action(() => downloadProgress.Value = i)
//);
}
}
}
}
if (tblcsv.Rows.Count > 0)
{
InsertCSVRecords(tblcsv);
}
worker.ReportProgress(100, "Done");
this.Dispatcher.Invoke(() => { textBox.Text = string.Empty; });
//textBox.Text = string.Empty;
this.Dispatcher.Invoke(()=> { label.Content = totalRows + " rows have been added or updated"; });
this.Dispatcher.Invoke(() => { button1.IsEnabled = false; });
//button1.IsEnabled = false;
}
private void button1_Click(object sender, RoutedEventArgs e)
{
BackgroundWorker bk = new BackgroundWorker();
bk.RunWorkerCompleted += Bk_RunWorkerCompleted;
bk.WorkerReportsProgress = true;
bk.DoWork += Bk_DoWork;
bk.ProgressChanged += Bk_ProgressChanged;
bk.RunWorkerAsync();
}
private void Bk_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
this.Dispatcher.Invoke(() => { downloadProgress.Value = e.ProgressPercentage; });
//downloadProgress.Value = e.ProgressPercentage;
}
//private void Bk_DoWork(object sender, DoWorkEventArgs e)
//{
// AddData();
// var worker = sender as BackgroundWorker;
// worker.ReportProgress(0, string.Format("This is new one"));
// for(int i=0;i<10;i++)
// {
// Thread.Sleep(1000);
// worker.ReportProgress((i + 1) * 10, string.Format("This is new one"));
// }
// worker.ReportProgress(100, "Done");
//}
private void Bk_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
MessageBox.Show("All Done");
this.Dispatcher.Invoke(() => { downloadProgress.Value = 0; });
}