无法在android

Question

在我的项目中，我无法将图像保存在所需的文件夹中。我检查了生成的路径 / storage / emulated / 0 / myImages ，同时调试不存在。我没理解为什么没有创建 myImages 文件夹。我已将<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />和READ_EXTERNAL_STORAGE添加到我的 AndroidManifest.xml 。这是我的错误日志：

  

W / System.err：java.io.IOException：没有这样的文件或目录   W / System.err：at   java.io.UnixFileSystem.createFileExclusively0（本机方法）   W / System.err：at   java.io.UnixFileSystem.createFileExclusively（UnixFileSystem.java:281）   W / System.err：at java.io.File.createNewFile（File.java:1000）   W / System.err：at   com.stegano.strenggeheim.fragment.FragmentEncode.saveImage（FragmentEncode.java:170）   W / System.err：at   com.stegano.strenggeheim.fragment.FragmentEncode.onActivityResult（FragmentEncode.java:136）   W / System.err：at   android.support.v4.app.FragmentActivity.onActivityResult（FragmentActivity.java:151）   W / System.err：at   android.app.Activity.dispatchActivityResult（Activity.java:7235）   W / System.err：at   android.app.ActivityThread.deliverResults（ActivityThread.java:4320）   W / System.err：at   android.app.ActivityThread.handleSendResult（ActivityThread.java:4367）   W / System.err：在android.app.ActivityThread.-wrap19（未知   资料来源：0）W / System.err：at   android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1649）   W / System.err：at   android.os.Handler.dispatchMessage（Handler.java:105）W / System.err：
  在android.os.Looper.loop（Looper.java:164）W / System.err：at   android.app.ActivityThread.main（ActivityThread.java:6541）   W / System.err：at java.lang.reflect.Method.invoke（Native Method）   W / System.err：at   com.android.internal.os.Zygote $ MethodAndArgsCaller.run（Zygote.java:240）   W / System.err：at   com.android.internal.os.ZygoteInit.main（ZygoteInit.java:767）

这是我的Java代码：

package com.stegano.strenggeheim.fragment;

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

import com.stegano.strenggeheim.R;
import com.stegano.strenggeheim.utils.PermissionUtility;

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


public class FragmentEncode extends Fragment {
    private static final String IMAGE_DIRECTORY = "/myImages";
    private static final int GALLERY = 0, CAMERA = 1;
    private static Uri contentURI;
    TextView imageTextMessage;
    ImageView loadImage;

    public FragmentEncode() {
    }

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

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

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

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_encode, container, false);

        imageTextMessage = view.findViewById(R.id.imageTextMessage);
        loadImage =  view.findViewById(R.id.loadImage);

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

    private void showPictureDialog(){
        AlertDialog.Builder pictureDialog = new AlertDialog.Builder(getContext());
        pictureDialog.setTitle("Select Action");
        String[] pictureDialogItems = {
                "Select photo from gallery",
                "Capture photo from camera",
                "Cancel"
        };
        pictureDialog.setItems(pictureDialogItems,
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        switch (which) {
                            case 0:
                                galleryIntent();
                                break;
                            case 1:
                                cameraIntent();
                                break;
                            case 2:
                                dialog.dismiss();
                                break;
                        }
                    }
                });
        pictureDialog.show();
    }

    @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) {
                contentURI = data.getData();
                try {
                    Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContext().getContentResolver(), contentURI);
                    String path = saveImage(bitmap);
                    Log.println(Log.INFO, "Message", path);
                    Toast.makeText(getContext(), "Image Saved!", Toast.LENGTH_SHORT).show();
                    loadImage.setImageBitmap(bitmap);
                    imageTextMessage.setVisibility(View.INVISIBLE);

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

        } else if (requestCode == CAMERA) {
            Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
            loadImage.setImageBitmap(thumbnail);
            saveImage(thumbnail);
            Toast.makeText(getContext(), "Image Saved!", Toast.LENGTH_SHORT).show();
            imageTextMessage.setVisibility(View.INVISIBLE);
        }
    }


    public String saveImage(Bitmap bmpImage) {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        bmpImage.compress(Bitmap.CompressFormat.PNG, 100, bytes);
        File encodeImageDirectory =
                new File(Environment.getExternalStorageDirectory() + IMAGE_DIRECTORY);

        if (!encodeImageDirectory.exists()) {
            encodeImageDirectory.mkdirs();
        }
        try {
            String uniqueId = UUID.randomUUID().toString();
            File f = new File(encodeImageDirectory, uniqueId + ".png");
            f.createNewFile();
            FileOutputStream fo = new FileOutputStream(f);
            fo.write(bytes.toByteArray());
            MediaScannerConnection.scanFile(getContext(),
                    new String[]{f.getPath()},
                    new String[]{"image/png"}, null);
            fo.close();

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