計算點擊次數並在另一個頁面上顯示[Windows Phone c＃]

Question

我想要計算button1在頁面1上點擊的次數，然後在textbox1中顯示頁面2上的點擊次數。

我試過下面的代碼，但它給我一個異常錯誤'String count = localSettings.Values [「Count」]。'。

有沒有另一種方法可以做我想做的事？

private void button1_Click(object sender, RoutedEventArgs e) 
    { 
     var localSettings = Windows.Storage.ApplicationData.Current.LocalSettings; 
     String count= localSettings.Values["Count"].ToString(); 
     int tc = int.Parse(count); 
     tc++; 
     localSettings.Values["Count"] = tc; 

    } 

第2頁

 var localSettings = Windows.Storage.ApplicationData.Current.LocalSettings; 
     textbox1.Text = localSettings.Values["Count"].ToString(); 

Answer 1

當您進入 「計數」 的第一次，它不存在。因此localSettings.Values["Count"]將爲空。然後，您嘗試在空對象上調用ToString（），並導致該異常。

試試這個：

private void button1_Click(object sender, RoutedEventArgs e) 
{ 
    var localSettings = Windows.Storage.ApplicationData.Current.LocalSettings; 
    int tc = 0; 
    if(localSettings.Values["Count"] != null) 
    { 
     String count= localSettings.Values["Count"].ToString(); 
     tc = int.Parse(count); 
    } 
    tc++; 
    localSettings.Values["Count"] = tc; 

}