# PagerGallerySaveDemo

**Repository Path**: jack_of_disco/pager-gallery-save-demo

## Basic Information

- **Project Name**: PagerGallerySaveDemo
- **Description**: B站学习，包括java和kt两个源码，https://www.bilibili.com/video/BV1hJ411e7PV
- **Primary Language**: Java
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 1
- **Forks**: 0
- **Created**: 2021-02-26
- **Last Updated**: 2021-10-08

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# PagerCallerySave 

- 结合PagerCallery项目笔记

- 与PagerCallery一样，多一个动态申请写的权限，因为要保存

- 提前占好宽高比，添加用户信息，点赞数，收藏数

   
  
- pojo添加图片高度，用户，点赞数，收藏数字段

  ```kotlin
  @Parcelize
  data class PhotoItem(
          @SerializedName("id") val photoId: Int,
          @SerializedName("webformatURL") val previewUrl: String,
          @SerializedName("largeImageURL") val fullUrl: String,
          @SerializedName("webformatHeight") val photoHeight: Int,
          @SerializedName("user") val photoUser: String,
          @SerializedName("likes") val photoLikes: Int,
          @SerializedName("favorites") val photoFavorites: Int
  
  ) : Parcelable
  ```

- 在cell_gallery布局上添加用户TextView,添加点赞数，添加收藏数

![输入图片说明](https://images.gitee.com/uploads/images/2021/0226/144930_5b14b0a5_5475989.png "image-20210226094353476.png")

- 既然修改了cell_gallery，那么gallery也要修改，来显示用户名字，点赞数，收藏数

  ```kotlin
  override fun onBindViewHolder(holder: GalleryViewHolder, position: Int) {
      val photoItem = getItem(position)
      holder.itemView.apply {
          shimmerLayout.apply {
              setShimmerAngle(30)
              setShimmerColor(0x55FFFFFF)
              startShimmerAnimation()
          }
          imageViewGallery.layoutParams.height = photoItem.photoHeight
          textViewUser.text = photoItem.photoUser
          textViewFavorites.text = photoItem.photoFavorites.toString()
          textViewLike.text = photoItem.photoLikes.toString()
  
  
      }
  
  
      Glide.with(holder.itemView)
              .load(getItem(position).previewUrl)
              .placeholder(R.drawable.ic_baseline_photo_24)
              .listener(object : RequestListener<Drawable> {
                  override fun onLoadFailed(e: GlideException?, model: Any?, target: Target<Drawable>?, isFirstResource: Boolean): Boolean {
                      Log.d("myTAG", "onLoadFailed: 图片加载失败")
                      return false
                  }
  
                  override fun onResourceReady(resource: Drawable?, model: Any?, target: Target<Drawable>?, dataSource: DataSource?, isFirstResource: Boolean): Boolean {
                      return false.also { holder.itemView.shimmerLayout.stopShimmerAnimation() }
                  }
              })
              .into(holder.itemView.imageViewGallery)
  }
  ```

- 在fragment_photo上添加一个下载的图片按钮

![输入图片说明](https://images.gitee.com/uploads/images/2021/0226/145040_b48d9c65_5475989.png "image-20210226094727085.png")


- 在PhotoFragment类中编写下载点击事件

  - 点击事件

    ```kotlin
    const val REQUEST_WRITE_EXTERNAL_STORAGE = 1//常量
    
    saveButton.setOnClickListener {
    
        if (Build.VERSION.SDK_INT < 29 && ContextCompat.checkSelfPermission(requireContext(),
                        Manifest.permission.WRITE_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(arrayOf(Manifest.permission.WRITE_EXTERNAL_STORAGE),
                    REQUEST_WRITE_EXTERNAL_STORAGE)
        } else {
            viewLifecycleOwner.lifecycleScope.launch {
                savePhoto()
            }
        }
        Log.e("myTAG", "onActivityCreated: 下载图片点击")
    }
    ```

  - 保存事件savePhoto

    ```kotlin
    private suspend fun savePhoto() {
        withContext(Dispatchers.IO) {
            val holder = (viewPager2[0] as RecyclerView).findViewHolderForAdapterPosition(viewPager2.currentItem)
                    as PhotoViewHolder
    
            val bitmap = holder.itemView.imageViewPhoto.drawable.toBitmap()
    
            val saveUri = requireContext().contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                    ContentValues()) ?: kotlin.run {
                Toast.makeText(requireContext(), "存储失败", Toast.LENGTH_LONG).show()
                return@withContext
            }
            requireContext().contentResolver.openOutputStream(saveUri).use {
                if (bitmap.compress(Bitmap.CompressFormat.JPEG, 90, it)) {
                    MainScope().launch { Toast.makeText(requireContext(), "存储成功", Toast.LENGTH_LONG).show() }
                } else {
                    Toast.makeText(requireContext(), "存储失败", Toast.LENGTH_LONG).show()
                }
            }
        }
    }
    ```

  - 重写onRequestPermissionsResult

    ```kotlin
    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        when (requestCode) {
            REQUEST_WRITE_EXTERNAL_STORAGE -> {
                if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    viewLifecycleOwner.lifecycleScope.launch {
                        savePhoto()
                    }
                } else {
                    Toast.makeText(requireContext(), "存储失败", Toast.LENGTH_LONG).show()
                }
            }
        }
    }
    ```

## JAVA版本

因为java版本没有找到协程，所以就直接进行了存储

```java
package com.zyl.pagergallerysave_java.fragment;

import android.Manifest;
import android.content.ContentValues;
import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.Lifecycle;
import androidx.lifecycle.LifecycleEventObserver;
import androidx.lifecycle.LifecycleOwner;
import androidx.recyclerview.widget.RecyclerView;
import androidx.viewpager2.widget.ViewPager2;

import android.os.Parcelable;
import android.provider.MediaStore;
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.zyl.pagergallerysave_java.R;
import com.zyl.pagergallerysave_java.adapter.GalleryAdapter;
import com.zyl.pagergallerysave_java.adapter.PhotoAdapter;

import java.io.FileNotFoundException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Arrays;


public class PhotoFragment extends Fragment {

    private ViewPager2 viewPager2;
    private TextView textViewNumber;
    private ImageView imageViewDownload;

    public static final int REQUEST_WRITE_EXTERNAL_STORAGE = 1;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_photo, container, false);
        viewPager2 = view.findViewById(R.id.viewPager2);
        textViewNumber = view.findViewById(R.id.textViewNumber);
        imageViewDownload = view.findViewById(R.id.imageViewDownload);
        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        PhotoAdapter photoAdapter = new PhotoAdapter();

        final ArrayList photoList = getArguments().getParcelableArrayList(GalleryAdapter.PHOTO_LIST);
        photoAdapter.submitList(photoList);
        viewPager2.setAdapter(photoAdapter);
        viewPager2.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
            @Override
            public void onPageSelected(int position) {
                super.onPageSelected(position);
                textViewNumber.setText(position + 1 + " / " + photoList.size());
            }
        });

        viewPager2.setCurrentItem(getArguments().getInt(GalleryAdapter.PHOTO_POSITION), false);
        viewPager2.setOrientation(ViewPager2.ORIENTATION_VERTICAL);
        imageViewDownload.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (Build.VERSION.SDK_INT < 29 && ContextCompat.checkSelfPermission(requireContext(),
                        Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                    //本地方法，需要重写
                    requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                            REQUEST_WRITE_EXTERNAL_STORAGE);
                } else {
                    savePhoto();
                }
            }
        });

    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == REQUEST_WRITE_EXTERNAL_STORAGE) {
            savePhoto();
        } else {
            Toast.makeText(requireContext(), "存储失败", Toast.LENGTH_SHORT).show();
        }
    }

    private void savePhoto() {
//        bitmap.compress(Bitmap.CompressFormat.PNG, 100, openFileOutput("picture", Context.MODE_PRIVATE));
//        new Thread(new Runnable() {
//            @Override
//            public void run() {
        RecyclerView recyclerView = (RecyclerView) viewPager2.getChildAt(0);
        PhotoAdapter.PhotoViewHolder holder = (PhotoAdapter.PhotoViewHolder) recyclerView.findViewHolderForAdapterPosition(viewPager2.getCurrentItem());

        Bitmap bitmap = ((BitmapDrawable) holder.photoView.getDrawable()).getBitmap();

        try {
            Uri saveUri = requireContext().getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                    new ContentValues());
            OutputStream outputStream = requireContext().getContentResolver().openOutputStream(saveUri);
            if (bitmap.compress(Bitmap.CompressFormat.JPEG, 90, outputStream)) {
                Log.d("myTAG", "run: 存储成功");
                Toast.makeText(requireContext(), "存储成功", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(requireContext(), "存储失败", Toast.LENGTH_SHORT).show();
            }
        } catch (Exception e) {
            Toast.makeText(requireContext(), "存储失败", Toast.LENGTH_SHORT).show();
            e.printStackTrace();
        }

//            }
//        }).start();
    }
}
```