无法从对话框结果隐式转换为bool

Question

我正在尝试将代码从wpf重现为winforms(此代码在wpf中运行)

public static bool? ShowSettingsDialogFor(ICustomCustomer)
{
   if (cust is BasicCustomer)
   {
      return (new BCustomerSettingsDialog()).ShowDialog();
   }
}

我收到编译错误消息

无法将类型'System.Windows.Forms.DialogResult'隐式转换为'bool？'

Answer 1

改变为

return (new BCustomerSettingsDialog()).ShowDialog() == DialogResult.OK;

Answer 2

原因是,在Windows窗体中,该ShowDialog方法返回DialogResult枚举值.可能值的范围取决于您可用的按钮,它们的bool?转换可能取决于它们在您的应用程序中的含义.以下是处理一些情况的一些通用逻辑:

public static bool? ShowSettingsDialogFor(ICustomCustomer)
{
   if (cust is BasicCustomer)
   {
      DialogResult result = (new BCustomerSettingsDialog()).ShowDialog();

      switch (result)
      {
          case DialogResult.OK:
          case DialogResult.Yes:
              return true;

          case DialogResult.No:
          case DialogResult.Abort:
              return false;

          case DialogResult.None:
          case DialogResult.Cancel:
              return null;

          default:
              throw new ApplicationException("Unexpected dialog result.")
      }
   }
}