| layout | title | redirect_from | |
|---|---|---|---|
page |
Hello World |
|
Having completed the steps in the getting started document you're ready to build your first app. To illustrate the process we will build a simple hello world application.
A simple app starts by creating an app instance with app.New() and then opening a window with app.NewWindow(). Then a widget tree is defined that is set as the main content with SetContent() on a window. The app UI is then shown by calling ShowAndRun() on the window.
```go
package main
import ( "fyne.io/fyne/v2/app" "fyne.io/fyne/v2/widget" )
func main() { a := app.New() w := a.NewWindow("Hello World")
w.SetContent(widget.NewLabel("Hello World!"))
w.ShowAndRun()
}
</div>
</div>
The code above can be built using the command `go build .` and then executed either by running the `hello` command or by double clicking the icon. You could also bypass the compiling step and just run the code directly using `go run .`.
Either approach will show a window that looks just like this:
<img src="/images/started/hello-dark.png" style="width: 120px; border: 1px solid #999; margin: 10pt" alt="Hello Window" />
If you prefer a light theme then just set the environment variable `FYNE_THEME=light` and you'll get:
<img src="/images/started/hello-light.png" style="width: 120px; border: 1px solid #999; margin: 10pt" alt="Hello Light Theme" />
That's all there is to getting started. To learn more you can read the full
[API documentation](http://developer.fyne.io/api/).
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