webRtc/Assets/Script/AndroidImagePicker.cs

namespace Unity.RenderStreaming
{
#if UNITY_ANDROID && !UNITY_EDITOR
    public class AndroidImagePicker : MonoBehaviour
    {
        private static AndroidImagePicker _instance;
        private Action<Texture2D> _callback;
        private AndroidJavaObject _activity;
        private bool _waitingForResult;
        private string _pickedImagePath;

        public static AndroidImagePicker Instance
        {
            get
            {
                if (_instance == null)
                {
                    var go = new GameObject(nameof(AndroidImagePicker));
                    DontDestroyOnLoad(go);
                    _instance = go.AddComponent<AndroidImagePicker>();
                }
                return _instance;
            }
        }

        public void PickImage(Action<Texture2D> onImagePicked)
        {
            _callback = onImagePicked;

            using (AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
            {
                _activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity");
            }

            _activity.Call("runOnUiThread", new AndroidJavaRunnable(() =>
            {
                using (AndroidJavaObject intent = new AndroidJavaObject("android.content.Intent",
                    "android.intent.action.PICK"))
                {
                    intent.Call<AndroidJavaObject>("setType", "image/*");
                    using (AndroidJavaObject i = intent.Call<AndroidJavaObject>("createChooser",
                        _activity, "选择头像"))
                    {
                        _activity.Call("startActivity", i);
                    }
                }
            }));

            _waitingForResult = true;
        }

        private void Update()
        {
            if (!_waitingForResult) return;

            try
            {
                if (_activity == null) return;
                using (AndroidJavaClass uriClass = new AndroidJavaClass("android.net.Uri"))
                {
                }
            }
            catch
            {
                // ignored
            }
        }
    }
#endif
}