Add text in c# forms WPF

Question

I want to a WPF project in c# and I want in my MainWindow interface to add a textbox. I use toolbox to add textBox field and with view code I found the following function:

private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
{

}

How can I change the default value of the textBox? The only thing the is generated when I add the Textbox was this function. Which variable is responsible for the text? EDIT: I am trying to modify a WPF application which is provided with the kinect SDK. It seems that is not that straight-forward. When I tried to right click on the textBox I cant see any properties option. Inside MainWIndow.xaml.cs there is a line with the property of the textbox:

<TextBox HorizontalAlignment="Left" Height="23" Margin="540,3,0,0" TextWrapping="Wrap" Text="0" VerticalAlignment="Top" Width="120" TextChanged="TextBox_TextChanged" Grid.ColumnSpan="3"/>

However I cant find the name of the textbox anywhere.

To get or change the text you should use the Text property – Dilshod Jul 14 '15 at 13:18 — Dilshod, Jul 14 '15 at 13:18

3-14159265358979323846264 · Accepted Answer · 2015-07-14T13:59:35.977

1

If you select the textbox and press F4 to access the selected item's properties (normally displayed in the bottom right of the screen), you can set the Text property in the property grid. The value you enter will be used when the form is first created. This is equivalent to setting the Text XAML attribute on the TextBox element.

In code, you can also do this in your constructor using textbox1.Text = "hello"; for instance.

Note, to access the TextBox in code you will need to assign it a name (also via the properties grid).

<TextBox x:Name="textbox1" Text="Default Value Goes Here" HorizontalAlignment="Left" Height="23" Margin="540,3,0,0" TextWrapping="Wrap" Text="0" VerticalAlignment="Top" Width="120" TextChanged="TextBox_TextChanged" Grid.ColumnSpan="3"/>

edited Jul 14 '15 at 13:59

answered Jul 14 '15 at 13:20

3-14159265358979323846264

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My problem is that where should I look for the generated textbox object. – Jose Ramon Jul 14 '15 at 13:53
If you go to the form designer, you should have the XAML code below inside which you will find a line like `` – 3-14159265358979323846264 Jul 14 '15 at 13:56
Yes I have already posted this line in the post. – Jose Ramon Jul 14 '15 at 13:57
Ok. I see that! You need to add an `x:Name` attribute ... i'll update my answer. – 3-14159265358979323846264 Jul 14 '15 at 13:58
I've also added the default value bit for you! – 3-14159265358979323846264 Jul 14 '15 at 14:01
I got textbox1 is a field but is used like a type error message. – Jose Ramon Jul 14 '15 at 14:01
What is the line of code that gives that error? `textbox1.Text="hello";` should work fine. NOTE: `TextBox` is a type, `textbox1` is an instance of a `TextBox` type. – 3-14159265358979323846264 Jul 14 '15 at 14:02
Exactly textbox1.Text = "hello"; – Jose Ramon Jul 14 '15 at 14:03
Well that sounds like you also have a field `textbox1` defined somewhere. Try changing `x:Name="MyTextbox"` and `MyTextbox.Text="hello";` – 3-14159265358979323846264 Jul 14 '15 at 14:08
Now I am getting NullReferenceException. – Jose Ramon Jul 14 '15 at 14:24
Really sorry, but I haven't got time to debug all your errors! `NullReference` implies that `MyTextBox` has not been assigned anything. This could be because you are accessing it before `InitialiseComponent` has run. Otherwise, you need to post your full code under a different question. Sorry I can't be more help. – 3-14159265358979323846264 Jul 14 '15 at 14:28

score 0 · Answer 2 · answered Jul 14 '15 at 13:19

0

The Text property is what holds the value of the textbox.

Textbox1.Text = " ";

answered Jul 14 '15 at 13:19

Adam

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Add text in c# forms WPF

2 Answers2