Question

我有一个片段，我从图库上传图片或从相机拍照，但在运行应用程序“App已停止”消息即将进入Android模拟器，应用程序无法打开。这是我的 FragmentEncode 类。这不是从图库中的图片或相机上传图像的正确方法吗？如果没有，那么正确的方法是什么？

import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.graphics.Bitmap;
import android.media.MediaScannerConnection;
import android.provider.MediaStore;
import android.os.Bundle;
import android.os.Environment;
import android.support.v4.app.Fragment;
import android.support.v7.app.AlertDialog;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Calendar;

import com.stegano.strenggeheim.R;


public class FragmentEncode extends Fragment {
    private ImageView imageview;
    private static final String IMAGE_DIRECTORY = "/encoded_image";
    private static final int GALLERY = 1, CAMERA = 2;
    Uri myPicture = null;
    Button buttonLoadImage;
    Context context = getContext();

    public FragmentEncode() {
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRetainInstance(true);

        buttonLoadImage = buttonLoadImage.findViewById(R.id.buttonLoadImage);
        imageview =  imageview.findViewById(R.id.imageToEncode);

        buttonLoadImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showPictureDialog();
            }
        });
    }

    private void showPictureDialog(){
        AlertDialog.Builder pictureDialog = new AlertDialog.Builder(context);
        pictureDialog.setTitle("Select Action");
        String[] pictureDialogItems = {
                "Select photo from gallery",
                "Capture photo from camera" };
        pictureDialog.setItems(pictureDialogItems,
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        switch (which) {
                            case 0:
                                choosePhotoFromGallary();
                                break;
                            case 1:
                                takePhotoFromCamera();
                                break;
                        }
                    }
                });
        pictureDialog.show();
    }

    public void choosePhotoFromGallary() {
        Intent galleryIntent = new Intent(Intent.ACTION_PICK,
                android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);

        startActivityForResult(galleryIntent, GALLERY);
    }

    private void takePhotoFromCamera() {
        Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, CAMERA);
    }

    @Override
    public View onCreateView(LayoutInflater inflater,
                             ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_encode, container, false);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {

        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == getActivity().RESULT_CANCELED) {
            return;
        }
        if (requestCode == GALLERY) {
            if (data != null) {
                Uri contentURI = data.getData();
                try {
                    Bitmap bitmap = MediaStore.Images.Media.getBitmap(context.getContentResolver(), contentURI);
                    String path = saveImage(bitmap);
                    Toast.makeText(context, "Image Saved!", Toast.LENGTH_SHORT).show();
                    imageview.setImageBitmap(bitmap);

                } catch (IOException e) {
                    e.printStackTrace();
                    Toast.makeText(context, "Failed!", Toast.LENGTH_SHORT).show();
                }
            }

        } else if (requestCode == CAMERA) {
            Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
            imageview.setImageBitmap(thumbnail);
            saveImage(thumbnail);
            Toast.makeText(context, "Image Saved!", Toast.LENGTH_SHORT).show();
        }
    }


    public String saveImage(Bitmap myBitmap) {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        myBitmap.compress(Bitmap.CompressFormat.JPEG, 90, bytes);
        File wallpaperDirectory = new File(
                Environment.getExternalStorageDirectory() + IMAGE_DIRECTORY);
        // have the object build the directory structure, if needed.
        if (!wallpaperDirectory.exists()) {
            wallpaperDirectory.mkdirs();
        }

        try {
            File f = new File(wallpaperDirectory, Calendar.getInstance()
                    .getTimeInMillis() + ".jpg");
            f.createNewFile();
            FileOutputStream fo = new FileOutputStream(f);
            fo.write(bytes.toByteArray());
            MediaScannerConnection.scanFile(context,
                    new String[]{f.getPath()},
                    new String[]{"image/jpeg"}, null);
            fo.close();

            return f.getAbsolutePath();
        } catch (IOException e1) {
            e1.printStackTrace();
        }
        return "";
    }
}

Answer 1

尝试

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setRetainInstance(true);

}

@Override
public View onCreateView(LayoutInflater inflater,
                         ViewGroup container,
                         Bundle savedInstanceState) {

    view = inflater.inflate(R.layout.fragment_encode, container, false);

    buttonLoadImage = buttonLoadImage.findViewById(R.id.buttonLoadImage);
    imageview =  imageview.findViewById(R.id.imageToEncode);

    buttonLoadImage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            showPictureDialog();
        }
    });

    return view;
}

及以下

Context context = getContext();

放入

View view;

如何在Fragment中选择图库或相机中的图像？

1 个答案: