c# - Visual Studio 2010中的错误对话框

我想在检索时显示一条带有用户友好消息的进度对话框数据。我正在使用Visual Studio2010。我尝试使用此代码/// <summary> /// Shows a progress message to the user. /// </summary> /// <param name="header">The header text for the dialog.</param> /// <param name="message">The message to be displayed in the dialog.</param> void ShowProgressMessage(string header, string message) { _isMessageDialogVisible = true; _controller = _metroWindow.ShowProgressAsync(header, message); } /// <summary> /// Closes a message dialog that is visible. /// </summary> void CloseProgressMessage() { if (_isMessageDialogVisible) { _isMessageDialogVisible = false; if (null != _controller) { var controller = _controller.Result; controller.CloseAsync(); } } }但它给出一个错误，指出：22 09 2015 [9] DEBUG - OPGSpiral Error App.AppDispatcherUnhandledException --- System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object.在MahApps.Metro.Controls.Dialogs.BaseMetroDialog.HandleTheme（）   在MahApps.Metro.Controls.Dialogs.BaseMetroDialog.Initialize（）   在MahApps.Metro.Controls.Dialogs.BaseMetroDialog..ctor中（MetroWindow owningWindow，MetroDialogSettings设置）   在MahApps.Metro.Controls.Dialogs.ProgressDialog..ctor（MetroWindow parentWindow，MetroDialogSettings设置）   在MahApps.Metro.Controls.Dialogs.ProgressDialog..ctor（MetroWindow parentWindow）   在MahApps.Metro.Controls.Dialogs.DialogManager。 c__DisplayClass43.b__3b（）   ---内部异常堆栈跟踪的结尾---   在System.RuntimeMethodHandle.InvokeMethod处（对象目标，对象[]参数，签名sig，布尔构造函数）   在System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal（Object obj，Object []参数，Object []参数）   在System.Delegate.DynamicInvokeImpl（Object [] args）   在System.Windows.Threading.ExceptionWrapper.InternalRealCall（委托回调，对象args，Int32 numArgs）   在System.Windows.Threading.ExceptionWrapper.TryCatchWhen（对象源，委托回调，对象args，Int32 numArgs，委托catchHandler）2015年9月22日[9]调试-OPGSpiral错误App.AppDispatcherUnhandledException --- System.Reflection.TargetInvocationException：调用的目标引发了异常。 ---> System.NullReferenceException：对象引用未设置为对象的实例。   在MahApps.Metro.Controls.Dialogs.BaseMetroDialog.HandleTheme（）   在MahApps.Metro.Controls.Dialogs.BaseMetroDialog.Initialize（）   在MahApps.Metro.Controls.Dialogs.BaseMetroDialog..ctor中（MetroWindow owningWindow，MetroDialogSettings设置）   在MahApps.Metro.Controls.Dialogs.ProgressDialog..ctor（MetroWindow parentWindow，MetroDialogSettings设置）   在MahApps.Metro.Controls.Dialogs.ProgressDialog..ctor（MetroWindow parentWindow）   在MahApps.Metro.Controls.Dialogs.DialogManager。 c__DisplayClass43.b__3b（）   ---内部异常堆栈跟踪的结尾---   在System.RuntimeMethodHandle.InvokeMethod处（对象目标，对象[]参数，签名sig，布尔构造函数）   在System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal（Object obj，Object []参数，Object []参数）   在System.Delegate.DynamicInvokeImpl（Object [] args）   在System.Windows.Threading.ExceptionWrapper.InternalRealCall（委托回调，对象args，Int32 numArgs）   在System.Windows.Threading.ExceptionWrapper.TryCatchWhen（对象源，委托回调，对象args，Int32 numArgs，委托catchHandler） (adsbygoogle = window.adsbygoogle || []).push({}); 最佳答案 这应该在1.2.2中修复，可以通过NuGet获得。 (adsbygoogle = window.adsbygoogle || []).push({});