TargetInvocationException被投擲c＃

Question

我有一個例程，這是一個後臺工作人員完成調用。如下;

private void BatteryListFetchBackgroundWorkerRunWorkerCompleter(object sender, RunWorkerCompletedEventArgs e) 
{ 
    this.Cursor = Cursors.Default; 
    var sortedList = this.currentBatteries.Values.OrderBy(g => g, new BatteryNameComparer()); //breaks here 

    this.BatteryBindingSource.DataSource = sortedList; 
    if (this.batteryListBox.Items.Count > 0) 
    { 
     this.batteryListBox.SetSelected(0, true); 
    } 

    this.viewScheduleButton.Enabled = true; 
    this.viewDefaultScheduleButton.Enabled = true; 
    this.viewEditScheduleLimits.Enabled = true; 
} 

它打破的路線是;

   this.BatteryBindingSource.DataSource = sortedList; 

唯一的例外是空引用異常，並設置數據源時

每當你看到一個TargetInvocationException爲BatteryNameComparer

public class BatteryNameComparer : IComparer<Battery> 
{ 
    /// <summary> 
    /// Compares DDSMGroup 
    /// </summary> 
    /// <param name="a">first value for comparison</param> 
    /// <param name="b">second value for comparison</param> 
    /// <returns>An integer indicating the compare result</returns> 
    public int Compare(Battery a, Battery b) 
    { 
     int aId = int.Parse(a.DeviceName.Substring(BatteryOverviewControl.BatteryPrefixSubstring.Length)); 
     int bId = int.Parse(b.DeviceName.Substring(BatteryOverviewControl.BatteryPrefixSubstring.Length)); 

     return aId.CompareTo(bId); 
    } 
} 

Answer 1

的代碼，你應該立即檢查其InnerException屬性發生找到實際拋出的異常。

http://msdn.microsoft.com/en-us/library/system.exception.innerexception(v=vs.110).aspx

簡單地說，TargetInvocationException只告訴另一個例外是某種調用上下文中拋出 - 這是幾乎總是一個橫紗操作或通過反射調用。