几秒钟后，UI消失了

Question

I've been building a Windows Phone app (8.1) that gets some JSON data, parses it, and then builds UI Elements as necessary. Getting and parsing work fine, and life is nice, but the UI Elements disappear after only a few seconds. An example can be seen here , where a user clicks a button and the Elements get created, but gets destro. Specifically this piece of code is how I'm implementing it.

private void doBuild(object sender, TappedRoutedEventArgs e) {
    Button myButton = new Button();
    myButton.Width = 160;
    myButton.Height = 72;
    myButton.Content = "Click Me";
    var margin = myButton.Margin;
    margin.Top = 250;
    margin.Left = 15;
    myButton.Margin = margin;
    LayoutRoot.Children.Add(myButton);
    LayoutRoot.UpdateLayout();
}

What am I doing wrong?

Answer 1

The problem is with your layout. You've set a width of 0% for the first column of your grid. Since your button is added per default to the first column, its width is set to 0.

Either change the size of your columns, or add the button to another column:

private void doBuild(object sender, TappedRoutedEventArgs e)
{
    Button myButton = new Button();
    myButton.Width = 160;
    myButton.Height = 72;
    myButton.Content = "Click Me";
    var margin = myButton.Margin;
    margin.Top = 250;
    margin.Left = 15;
    myButton.Margin = margin;

    Grid.SetColumn(myButton, 1);

    LayoutRoot.Children.Add(myButton);
    LayoutRoot.UpdateLayout();
}