title: SwiftUI @State var initialization issue
body: <p>I would like to initialise the value of a <code>@State</code> var in SwiftUI through the <code>init()</code> method of a <code>Struct</code>, so it can take the proper text from a prepared dictionary for manipulation purposes in a TextField.
  The source code looks like this:</p>
  <pre><code>struct StateFromOutside: View {
      let list = [
          &quot;a&quot;: &quot;Letter A&quot;,
          &quot;b&quot;: &quot;Letter B&quot;,
          // ...
      ]
      @State var fullText: String = &quot;&quot;
  
      init(letter: String) {
          self.fullText = list[letter]!
      }
  
      var body: some View {
          TextField($fullText)
      }
  }
  </code></pre>
  <p>Unfortunately the execution fails with the error <code>Thread 1: Fatal error: Accessing State&lt;String&gt; outside View.body</code></p>
  <p>How can I resolve the situation? Thank you very much in advance!</p>