Question

我正在尝试计算在第1页上点击button1的次数，然后在textbox1中显示第2页的点击次数。

我尝试在下面进行编码，但它在行' String count = localSettings.Values [“Count”]上给我一个异常错误.ToString（）; '。

还有其他办法可以做我想做的事吗？

Page 1

  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页

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

Answer 1

第一次访问“计数”时，它不存在。因此localSettings.Values["Count"]将为空。然后尝试在一个null的对象上调用ToString（），这会导致异常。

试试这个：

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;

}

计算点击次数并在另一页上显示[Windows Phone c＃]

1 个答案: