点击相册，选中后上传图像

• 1. 添加权限与依赖

权限

        <uses-permission android:name="android.permission.INTERNET"></uses-permission>
        <uses-permission android:name="android.permission.CAMERA"></uses-permission>
        <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
        <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>

依赖

        //retrofit基本依赖
        implementation 'com.squareup.retrofit2:retrofit:2.3.0'
        implementation 'io.reactivex.rxjava2:rxjava:2.0.1'    //RxJava
        implementation 'io.reactivex.rxjava2:rxandroid:2.0.1'
        implementation 'com.squareup.retrofit2:adapter-rxjava2:2.3.0'
        implementation 'com.squareup.retrofit2:converter-gson:2.3.0'


        implementation 'com.squareup.okhttp3:okhttp:3.10.0'//okhttp3
        implementation 'com.google.code.gson:gson:2.2.4'//gson

        implementation 'com.android.support:design:27.1.1'  //防止版本错误
        implementation 'com.github.bumptech.glide:glide:3.8.0'        //解析图片（glide图片加载框架）
        implementation 'com.squareup.picasso:picasso:2.3.2'        //解析图片

• 2. 在activity_main.xml 中布局

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btn1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="拍照" />

    <Button
        android:id="@+id/btn2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="相册" />

    <ImageView
        android:id="@+id/img"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

• 3. 需要使用到的实体类

public class UpLoadBean {


    /**
     * code : 200
     * res : 上传文件成功
     * data : {"url":"http://yun918.cn/study/public/uploadfiles/123/944365-ee747d1e331ed5a4.png"}
     */

    private int code;
    private String res;
    private DataBean data;

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getRes() {
        return res;
    }

    public void setRes(String res) {
        this.res = res;
    }

    public DataBean getData() {
        return data;
    }

    public void setData(DataBean data) {
        this.data = data;
    }

    public static class DataBean {
        /**
         * url : http://yun918.cn/study/public/uploadfiles/123/944365-ee747d1e331ed5a4.png
         */

        private String url;

        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }
    }
}

• 4. 在Activity 中实现效果

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    /**
     * 拍照
     */
    private Button mBtn1;
    /**
     * 相册
     */
    private Button mBtn2;
    private ImageView mImg;
    private int ALBUM_CODE = 200;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        mBtn1 = (Button) findViewById(R.id.btn1);
        mBtn1.setOnClickListener(this);
        mBtn2 = (Button) findViewById(R.id.btn2);
        mBtn2.setOnClickListener(this);
        mImg = (ImageView) findViewById(R.id.img);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            default:
                break;
            case R.id.btn1:
                break;
            case R.id.btn2:
                takePICK();
                break;
        }
    }


    private void takePICK() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
            openAlbum();
        } else {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 200);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

            if (requestCode == 200) {
                openAlbum();
            }
        }
    }


    //打开相册
    private void openAlbum() {

        //启动相册
        Intent intent = new Intent(Intent.ACTION_PICK);
        intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");
        startActivityForResult(intent, ALBUM_CODE);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (resultCode == RESULT_OK){//判断回调成功

            if (requestCode == ALBUM_CODE) {//相册

                //获取到相册选中后的图片URI路径
                Uri imageUri = data.getData();

                //显示相册选中后的图片
                try {
                    Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
                    mImg.setImageBitmap(bitmap);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }

                //文件上传，将Uri路径转换为File对象
                //处理uri,7.0以后的fileProvider 把URI 以content provider 方式 对外提供的解析方法
                /*File file = getFileFromUri(imageUri, this);

                if (file.exists()){
                    uploadFile(file);
                }*/
            }
        }
    }

    private void uploadFile(File file) {

        String url = "http://yun918.cn/study/public/file_upload.php";

        OkHttpClient client = new OkHttpClient.Builder()
                .build();

        RequestBody requestBody = RequestBody.create(MediaType.parse("image/jpg"), mFile);
        MultipartBody body = new MultipartBody.Builder()
                .setType(MultipartBody.FORM)
                .addFormDataPart("key", "fafda")
                .addFormDataPart("file", mFile.getName(), requestBody)
                .build();

        Request request = new Request.Builder()
                .url(url)
                .post(body)
                .build();

        Call call = client.newCall(request);

        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                Log.d(TAG, "onFailure: " + e.getMessage());
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                String result = response.body().string();

                Gson gson = new Gson();
                final UpLoadBean upLoadBean = gson.fromJson(result, UpLoadBean.class);

                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {

                        if (upLoadBean != null) {
                            if (upLoadBean.getCode() == 200) {
                                Toast.makeText(MainActivity.this, upLoadBean.getRes(), Toast.LENGTH_SHORT).show();

                                Glide.with(MainActivity.this).load(upLoadBean.getData().getUrl()).into(mImg);

                                Log.d(TAG, "run: " + upLoadBean.getData().getUrl());

                            } else {
                                Toast.makeText(MainActivity.this, upLoadBean.getRes(), Toast.LENGTH_SHORT).show();
                            }
                        }


                    }
                });


            }
        });


    }

}