NavigationService.navigate空引用异常

Question

我正在学习WP编码,我遇到了无法解决的问题:/

try
 {
    NavigationService.Navigate(new Uri("/edit.xaml", UriKind.Relative));
 }
 catch (Exception ex)
 {
     MessageBox.Show(ex.Message.ToString(),"Error!",MessageBoxButton.OK);
 }

edit.xaml与MainPage.xaml位于同一目录中

它抛出"NullReferenceException"

Answer 1

因为你得到了NullReferenceException,我的猜测是你试图提前调用NavigationService.Navigate,例如在MainPage构造函数中.

相反,如果您想在加载页面时立即导航,请尝试OnNavigatedTo通过将此代码添加到MainPage类来覆盖事件来执行此操作:

protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
{
   NavigationService.Navigate(new Uri("/Page1.xaml", UriKind.Relative));
}