SwiftUI:
«`swift
import SwiftUI
struct DocumentPickerView: View {
    @State private var documentURL: URL?
    var body: some View {
        VStack {
            if let documentURL = documentURL {
                Text(«Selected File: (documentURL.lastPathComponent)»)
            } else {
                Button(«Open Document») {
                    let documentPicker = UIDocumentPickerViewController(forOpeningContentTypes: [.text, .pdf])
                    documentPicker.delegate = self
                    present(documentPicker, animated: true)
                }
            }
        }
    }
}
extension DocumentPickerView: UIDocumentPickerDelegate {
    func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
        guard let documentURL = urls.first else { return }
        self.documentURL = documentURL
    }
    func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
        // Handle cancellation
    }
}
«`
UIKit:
«`swift
import UIKit
class DocumentPickerViewController: UIViewController, UIDocumentPickerDelegate {
    override func viewDidLoad() {
        super.viewDidLoad()
        let documentPicker = UIDocumentPickerViewController(documentTypes: [«public.text», «public.pdf»], in: .import)
        documentPicker.delegate = self
        self.present(documentPicker, animated: true, completion: nil)
    }
    func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
        guard let documentURL = urls.first else { return }
        // Handle selected document
    }
    func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
        // Handle cancellation
    }
}
«`