Question

当我单击“清除”时，我想从选择器和条目中清除保存的数据。但是我单击它，它并不能立即清除。我必须关闭该应用，然后重新打开，这很清楚。我尝试输入空字符串“”，但它给了我错误，然后再次打开它冻结了我的应用程序。

void clearHandle_Clicked(object sender, System.EventArgs e)
{   
Settings.ClearAllData();
}

//then added to push empty string but got error
//UIApplication.Main(args, null, "AppDelegate");


void clearHandle_Clicked(object sender, System.EventArgs e)
{
DisplayAlert("EDIT", "Are you sure you want to clear data ", "OK");
nameEntry.Text = "";
nxPicker.SelectedItem = "";
locationPicker1.SelectedItem = "";
locationPicker2.SelectedItem = "";
locationPicker3.SelectedItem = "";
locationPicker4.SelectedItem = "";
locationPicker5.SelectedItem = "";
locationPicker6.SelectedItem = "";
locationPicker7.SelectedItem = "";
locationPicker8.SelectedItem = "";
Settings.ClearAllData();

}

Answer 1

有趣的Click事件有时会在Xamarin中的Forms和Native委托上运行。因此，建议将清除的请求包装在UI调度程序委托中，如下所示：

void clearHandle_Clicked(object sender, System.EventArgs e)
{   
    Xamarin.Forms.Device.BeginInvokeOnMainThread(()=>{
        Settings.ClearAllData();
    });    
}


void clearHandle_Clicked(object sender, System.EventArgs e)
{
    DisplayAlert("EDIT", "Are you sure you want to clear data ", "OK");
    nameEntry.Text = "";
    nxPicker.SelectedItem = "";
    locationPicker1.SelectedItem = "";
    locationPicker2.SelectedItem = "";
    locationPicker3.SelectedItem = "";
    locationPicker4.SelectedItem = "";
    locationPicker5.SelectedItem = "";
    locationPicker6.SelectedItem = "";
    locationPicker7.SelectedItem = "";
    locationPicker8.SelectedItem = "";
    Xamarin.Forms.Device.BeginInvokeOnMainThread(()=>{
        Settings.ClearAllData();
    });
}

Xamarin，我如何立即从选择器和Entry中清除数据。使用montemagno Xamarin.plugins.setting

1 个答案: