如何在C＃Windows Phone中检查和更改名称按钮

Question

I have a problem, I'm making an easy game noughts and crosses on Windows Phone with Buttons:

<Button x:Name="ba0" Content=" " HorizontalAlignment="Left" Height="126" Margin="37,146,0,0" VerticalAlignment="Top" Width="126" Click="a0"/>

I would like to change the content of the button if on the button there's " " and not to change if there's "X" or "O". I wrote something like that:

public void a0(object sender, System.EventArgs e)
{
    if (ba0.Content == " ")
        ba0.Content = "X";
    else
         return;
}

But it doesn't work properly. Any idea?

Answer 1

Try following code:

<Button x:Name="ba0" HorizontalAlignment="Left" Height="126" Margin="37,146,0,0" VerticalAlignment="Top" Width="126" Click="a0"/>

public void a0(object sender, System.EventArgs e)
{
    if (string.IsNullOrEmpty(Convert.ToString(ba0.Content)))
        ba0.Content = "X";
    else
        return;
}

Answer 2

Try the following

Convert the content into string type and also trim the value.

public void a0(object sender, System.EventArgs e)
        {
            if (string.IsNullOrEmpty(Convert.ToString(ba0.Content).Trim()))
                ba0.Content = "X";
            else
                return;
        }

or check for white spaces

public void a0(object sender, System.EventArgs e)
    {
        var content = Convert.ToString(ba0.Content);
        if (string.IsNullOrEmpty(content) || string.IsNullOrWhiteSpace(content))
            ba0.Content = "X";
        else
            return;
    }