BackgroundWorker - C＃

Question

我正在開發一個使用BackroundWorker的多線程應用程序。在Do_Work方法中，我調用另一個方法，在該方法中，我使用while語句將大量數據添加到列表中。我的目標是添加列表中要顯示在GridView中的所有數據。我怎麼能這樣做，所以每次數據添加到列表中，gridview取決於？而不是等到while語句完成運行。當while-statment向列表中添加一個值時，該值會插入到gridview中？

它必須在ProgressChanged中，但我不知道該怎麼做。

Answer 1

This migh幫助。我有一個名爲的WorkerThread類做的工作，我們在的WorkerThread類要

static void Main(string[] args) 
{ 
    // create the background worker object 
    BackgroundWorker _worker = new BackgroundWorker(); 

    // tell the background worker it can be cancelled and report progress 
    _worker.WorkerReportsProgress = true; 
    _worker.WorkerSupportsCancellation = true; 

    // a worker thread object where the actual work happens 
    WorkerThread thread = new WorkerThread(); 

    // add our event handlers 
    _worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(thread.RunWorkerCompleted); 
    _worker.ProgressChanged += new ProgressChangedEventHandler(thread.ProgressChanged); 
    _worker.DoWork += new DoWorkEventHandler(thread.DoWork); 

    // start the worker thread 
    _worker.RunWorkerAsync(); 

    // wait for it to be completed 
    while(!_worker.CancellationPending) 
    { 
     // sleep for a second 
     Thread.Sleep(1000); 
    } 

    Console.ReadKey(); 

} 

現在

public class WorkerThread 
{ 
    public void DoWork(object sender, DoWorkEventArgs e) 
    { 
     //get a handle on the worker that started this request 
     BackgroundWorker workerSender = sender as BackgroundWorker; 

     // loop through 10 times and report the progress back to the sending object 
     for(int i = 0; i < 10; i++) 
     { 
      // tell the worker that we want to report progress being made 
      workerSender.ReportProgress(i); 
      Thread.Sleep(100); 
     } 

     // cancel the thread and send back that we cancelled 
     workerSender.CancelAsync(); 
     e.Cancel = true; 

    } 

    public void RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) 
    { 
     Console.WriteLine("Worker Done!!");   
    } 

    public void ProgressChanged(object sender, ProgressChangedEventArgs e) 
    { 
     // print out the percent changed 
     Console.WriteLine(e.ProgressPercentage); 
    } 
} 

我使用的是自定義類，你可以用你的類中的方法是創建背景工作者。只需修改ProgressChanged事件中的代碼即可。

Answer 2

我的方法是創建一個類，它可以容納我來回傳遞的任何數據。當您致電ReportProgress時，它將需要百分比增量和對象參數。將類放入此對象參數中，並從ProgressChanged事件中通過ProgressChangedEventArgs使此對象可用。然後，您可以讀取這些數據，將其輸入到您想要更新的控件中，然後調用該控件上的Refresh()方法在UI中更新它，而不會凍結該界面。

http://msdn.microsoft.com/en-us/library/a3zbdb1t.aspx

http://msdn.microsoft.com/en-us/library/system.componentmodel.backgroundworker.progresschanged.aspx

編輯：（僞代碼，未經測試）

private List<Customer> _customerList = new List<Customer>(); 

protected void DoWork(object sender, DoWorkEventArgs e) 
{ 
    MyDataGridView.DataSource = _customerList; // Here is where you'll set your data source and bindings 
    Load_Customer_Method(); 
} 

private void Load_Customer_Method() 
{ 
    int totalCustomers = 20; 
    int currentCustomer = 1; 

    for(currentCustomer = 1; currentCustomer <= totalCustomers; currentCustomer++) 
    { 
     Customer c = new Customer(); 
     // Configure customer 

     ReportProgress(100*currentCustomer/totalCustomers, c); 
    } 
} 

private void ProgressChanged(object sender, ProgressChangedEventArgs e) 
{ 
    Customer addedCustomer = (Customer)e.UserState; 
    _customerList.Add(addedCustomer); // If bindings are set, this update is automatic 
    MyDataGridView.Refresh(); // Force a refresh of the screen for this grid to make 
           // it appear as if the grid is populating one object at 
           // a time. 
} 

Answer 3

我建議你在閱讀的BackgroundWorker。你把所有的信息和例子有：

http://msdn.microsoft.com/en-us/library/system.componentmodel.backgroundworker.aspx

所有你需要做的是通過您的項目在ReportProgress和事件參數ProgressChanged在網格中添加您的項目。

Answer 4

給你的工人

添加一個進步改變了事件處理程序在你Do_Work方法

BackgroundWorker worker = sender as BackgroundWorker; 

    worker.ReportProgress(0, new DataObject()) 

在你陸侃處理

DataObject data (DataObject)e.UserState; 
    yourList.Add(data); 

如果你知道你有多長時間了，您可以發送在ReportProgess中的實際完成計數而不是0.