在wpf c＃中看不到stackpanel中动态添加的控件

Question

I am dynamically adding textboxes based on a button click inside the stackpanel.But the textboxes are not visible in the UI . Here is the code used for creating textboxs inside stackpanel.

 public void GenerateControls()
 {
     TextBox txtNumber = new TextBox();
     txtNumber.Name = "txtNumber";
     txtNumber.Text = "1776";
     txtNumber.Background= Brushes.Red;
     panel1.Children.Add(txtNumber);
 }

why its not visible..??and here is the XAML part of stackpanel

<StackPanel Name="panel1" Grid.Column="1" HorizontalAlignment="Left" Height="151" Margin="427,60,0,0" Grid.Row="2" VerticalAlignment="Top" Width="216">
    <StackPanel Height="144">

    </StackPanel>
</StackPanel>

Answer 1

If you are going to be adding controls dynamically, do not restrict the height (or even width) of the container you are adding to.

Update your XAML to have auto height/width.

<StackPanel Name="panel1" 
            Grid.Column="1"
            Height="Auto"
            Width="Auto" 
            Margin="427,60,0,0" 
            Grid.Row="2" 
            VerticalAlignment="Top"
            HorizontalAlignment="Left" >
    <StackPanel Height="144">

    </StackPanel>
</StackPanel>

Also, once you add a new child, make sure you are updating the StackPanel layout.

public void GenerateControls()
{
    TextBox txtNumber = new TextBox();
    txtNumber.Name = "txtNumber";
    txtNumber.Text = "1776";
    txtNumber.Background= Brushes.Red;

    panel1.Children.Add(txtNumber);
    panel1.UpdateLayout();
}

Answer 2

In your xaml code, there is a stackpanel in your 'panel', it will be the 1st child of 'panel'.

And its height is 144px. your 'panel1' is 151 px.

So when you add textboxes into 'panel', they will be displayed behind the 144px stackpanel.

There is only 7px to display them. So they will not display on your window.