从图库中选择图像并在图像视图中创建缩略图

Question

我一直在努力让画廊正常工作。部分是因为它是一个片段。 我想在这个片段中做的是拾取图像，在我的应用程序文件夹中制作副本，将图像缩放到我的图像视图以获取缩略图。此外，在应用程序的其他部分使用此图像，因此保存图像的位置。我正在使用 Realm 来保存该位置。

感谢您的帮助

代码如下：

import android.content.Context;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.widget.AppCompatImageView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.content.Intent;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;

import com.heinrichreimersoftware.materialintro.slide.FragmentSlide;

import io.realm.Realm;

public class Step3 extends FragmentSlide.FragmentSlideFragment implements View.OnClickListener {
    boolean STEP3_PROCEEDABLE = true;
    private static final int PICK_IMAGE = 1;
    AppCompatImageView imgView;
    Button imgButton;

    private OnFragmentInteractionListener mListener;

    public Step3(){
        //Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     */
    public static Step3 newInstance() {
        Step3 fragment = new Step3();
        return fragment;
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        final View rootView = inflater.inflate(R.layout.add_routine_slide3, container, false);
        imgButton = (Button) rootView.findViewById(R.id.imgButton);
        imgView = (AppCompatImageView) rootView.findViewById(R.id.imgView);
        imgButton = (Button) inflater.inflate(R.layout.add_routine_slide3, container, false);
        imgButton.setOnClickListener(this);
        return rootView;
    }

    public void onButtonPressed() {
        if (mListener != null) {
            mListener.onFragmentInteraction(STEP3_PROCEEDABLE);
        }
        Intent getIntent = new Intent(Intent.ACTION_GET_CONTENT);
        getIntent.setType("image/*");

        Intent pickIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
        pickIntent.setType("image/*");

        Intent chooserIntent = Intent.createChooser(getIntent, "Select Image");
        chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Intent[] {pickIntent});

        startActivityForResult(chooserIntent, PICK_IMAGE);

    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }



    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p/>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        void onFragmentInteraction(boolean proceedable);
    }
}

这里是xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingBottom="@dimen/activity_vertical_margin">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:layout_gravity="center"
        android:gravity="center"
        android:foregroundGravity="center"
        android:weightSum="1">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Rou_Image"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:gravity="center"
            />
        <TextView
            android:paddingTop="@dimen/activity_vertical_margin"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Add a picture to capture your routine."
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:gravity="center"
            />

        <Button
            android:text="Select Image"
            android:layout_width="158dp"
            android:layout_height="wrap_content"
            android:id="@+id/imgButton" />

        <AppCompatImageView
            android:layout_width="137dp"
            android:layout_height="wrap_content"
            app:srcCompat="@android:drawable/gallery_thumb"
            android:id="@+id/imgView"
            android:layout_weight="0.20" />
    </LinearLayout>
</LinearLayout>

Answer 1

您可以查看毕加索图书馆。您可以按照for3st 的说明从 Storage 加载图像并将其显示到 ImageView。

File f = new File("path-to-file/file.png")
Picasso.with(getActivity()).load(f).into(imageView);

此外，您还可以使用它来缩放图像

Picasso.with(getActivity()).load(f).resize(100,100).into(imageView);

要将图像保存在您的应用目录中，您可以像这样使用它

Bitmap bitmap;
Picasso.with(getActivity()).load(f).resize(100,100).into(imageView, new Callback() {
            @Override
            public void onSuccess() {
                bitmap = ((BitmapDrawable)image.getDrawable()).getBitmap();
            }

            @Override
            public void onError() {
            }
        });
File directory = new File(Environment.getExternalStorageDirectory().toString()+"/MyAppFolder");
if(!directory.exists()){    
   directory.mkdirs();
}
File file = new File(directory,new Random().nextInt(10000)+".png");
            try {
                FileOutputStream fos = new FileOutputStream(file);
                bitmap.compress(Bitmap.CompressFormat.PNG,100,fos);
                fos.flush();
                fos.close();
            }catch (IOException e){e.printStackTrace();}

            //Gallery Refresh
MediaScannerConnection.scanFile(getApplicationContext(), new String[]{Environment.getExternalStorageDirectory().toString()}, null, new MediaScannerConnection.OnScanCompletedListener() {

                public void onScanCompleted(String path, Uri uri) {
                    Log.e("ExternalStorage", "Scanned " + path + ":");
                    Log.e("ExternalStorage", "-> uri=" + uri);
                }
            });

希望这会有所帮助。