Android 10.0调用相机和相册

首先判断版本，判断是否授权，如果未授权，采用弹出框动态授权。

如果版本号大于7.0采用虚拟路径临时保存，如果版本号小于7.0采用绝对路径。

先使用PackageManager.checkPermission检测对方的app有没有取得文件读写权限。如果有的话，给对方发送file://格式URI。如果没有的话，给对方发送FileProvider生成的URI并临时授权

1.easypermissions动态权限申请框架

implementation 'pub.devrel:easypermissions:3.0.0'

2.相关权限AndroidMainfast.xml
FileProvider的使用（Android 7.0 行为变更 通过FileProvider在应用间共享文件）
第一步 声明FIleProvider
为什么要声明呢？
因为FileProvider是ContentProvider子类
注意需要设置一个meta-data，里面指向一个xml文件。

   <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application>
······
<provider
            android:name="androidx.core.content.FileProvider"
            android:authorities="com.baoming.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true"
            tools:replace="android:authorities">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/provider_paths" />
        </provider>
    </application>

3.xml文件provider_paths.xml
为什么要写这么个xml文件？
因为要使用content://uri替代file://uri，那么，content://的uri如何定义呢？总不能使用文件路径。
所以，需要一个虚拟的路径对文件路径进行映射，所以需要编写个xml文件，通过path以及xml节点确定可访问的目录，通过name属性来映射真实的文件路径。

<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="camera_photos" path="."/>
</paths>

4.MainActivity.java,布局类代码省略，2个按钮一个imageview控件

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.FileProvider;
import pub.devrel.easypermissions.AfterPermissionGranted;
import pub.devrel.easypermissions.AppSettingsDialog;
import pub.devrel.easypermissions.EasyPermissions;

import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.StrictMode;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import java.io.File;
import java.util.List;

public class MainActivity extends AppCompatActivity  implements EasyPermissions.PermissionCallbacks{
    private static final int RC_EXTERNAL_STORAGE_PERM = 100;
    private String bitmappath;
    private Uri cramuri;
    private File file2;
    private File currentImageFile = null;
    private Context context;
    private ImageView imageView;
    private Button btcamera;
    private Button btablum;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context=this;

        imageView=findViewById(R.id.imageView);
        btablum=findViewById(R.id.btablum);
        btcamera=findViewById(R.id.btcamera);

        requiresPermission();

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
            StrictMode.setVmPolicy(builder.build());
            builder.detectFileUriExposure();
        }

        btcamera.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
                    currentImageFile = new File(context.getExternalFilesDir(Environment.DIRECTORY_PICTURES), System.currentTimeMillis() + ".jpg");
                }
                // 启动系统相机
                Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                    cramuri = FileProvider.getUriForFile(MainActivity.this, "com.fileprovider", currentImageFile);
                    intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
                } else {
                    cramuri = Uri.fromFile(currentImageFile);
                }
                intent.putExtra(MediaStore.EXTRA_OUTPUT, cramuri);
                startActivityForResult(intent,2);
            }
        });

        btablum.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(Intent.ACTION_PICK, null);
                intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");
                startActivityForResult(intent,1);
            }
        });
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
            // 调用相机后返回
            case 1:
                if (resultCode == RESULT_OK) {
                    if (data != null) {
                        // 得到图片的全路径
                        Uri uri = data.getData();
                        startPhotoZoom(uri);
                    }
                }
                break;
            case 2:
                if (resultCode == RESULT_OK) {
                    startPhotoZoom(cramuri);
                }
                break;
            case 3:
                imageView.setImageURI(Uri.fromFile(file2));
                String file = ImageUtils.getRealPathFromUri(MainActivity.this, Uri.fromFile(file2));
                //转base64
                bitmappath = ImageUtils.getImgStr(file);
        }
    }

    //裁剪并压缩图片
    public void startPhotoZoom(Uri uri) {
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            file2 = new File(context.getExternalFilesDir(Environment.DIRECTORY_PICTURES), System.currentTimeMillis() + ".jpg");
        }

        Intent intent = new Intent("com.android.camera.action.CROP"); // 裁剪图片意图
        intent.setDataAndType(uri, "image/*");
        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
        intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
        intent.putExtra("crop", "true");
        intent.putExtra("aspectX", 1);//裁剪框 X 比值
        intent.putExtra("aspectY", 1);
        intent.putExtra("outputX", 600);//裁剪后输出宽度
        intent.putExtra("outputY", 600);
        intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file2));
        intent.putExtra("return-data", false); //是否在Intent中返回数据
        intent.putExtra("outputFormat", Bitmap.CompressFormat.JPEG.toString());// 图片格式
        intent.putExtra("noFaceDetection", true);// 取消人脸识别
        startActivityForResult(intent, 3);
    }


    @AfterPermissionGranted(RC_EXTERNAL_STORAGE_PERM)
    private void requiresPermission() {
        String[] perms = {Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.CAMERA};
        if (EasyPermissions.hasPermissions(MainActivity.this, perms)) {
        } else {
            EasyPermissions.requestPermissions(this,  getResources().getString(R.string.tips_crema), RC_EXTERNAL_STORAGE_PERM, perms);
        }
    }

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


    @Override
    public void onPermissionsGranted(int requestCode, @NonNull List perms) {

    }

    @Override
    public void onPermissionsDenied(int requestCode, @NonNull List perms) {
        new AppSettingsDialog.Builder(this)
                .setTitle(getResources().getString(R.string.tips_limit))
                .setPositiveButton(getResources().getString(R.string.tips_limit_true))
                .setNegativeButton(getResources().getString(R.string.tips_limit_false))
                .setRationale(getResources().getString(R.string.tips_limit_crema))
                .setRequestCode(RC_EXTERNAL_STORAGE_PERM)
                .build()
                .show();
    }
}

4.ImageUtils.java工具类

public class ImageUtils {

    /**
     * 根据图片的Uri获取图片的绝对路径。@uri 图片的uri
     * @return 如果Uri对应的图片存在,那么返回该图片的绝对路径,否则返回null
     */
    public static String getRealPathFromUri(Context context, Uri uri) {
        if(context == null || uri == null) {
            return null;
        }
        if("file".equalsIgnoreCase(uri.getScheme())) {
            return getRealPathFromUri_Byfile(context,uri);
        } else if("content".equalsIgnoreCase(uri.getScheme())) {
            return getRealPathFromUri_Api11To18(context,uri);
        }
        return getRealPathFromUri_AboveApi19(context, uri);//没用到
    }

    //针对图片URI格式为Uri:: file:///storage/emulated/0/DCIM/Camera/IMG_20170613_132837.jpg
    private static String getRealPathFromUri_Byfile(Context context,Uri uri){
        String uri2Str = uri.toString();
        String filePath = uri2Str.substring(uri2Str.indexOf(":") + 3);
        return filePath;
    }

    /**
     * 适配api19以上,根据uri获取图片的绝对路径
     */
    @SuppressLint("NewApi")
    private static String getRealPathFromUri_AboveApi19(Context context, Uri uri) {
        String filePath = null;
        String wholeID = null;

        wholeID = DocumentsContract.getDocumentId(uri);

        // 使用':'分割
        String id = wholeID.split(":")[1];

        String[] projection = { MediaStore.Images.Media.DATA };
        String selection = MediaStore.Images.Media._ID + "=?";
        String[] selectionArgs = { id };

        Cursor cursor = context.getContentResolver().query(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI, projection,
                selection, selectionArgs, null);
        int columnIndex = cursor.getColumnIndex(projection[0]);

        if (cursor.moveToFirst()) {
            filePath = cursor.getString(columnIndex);
        }
        cursor.close();
        return filePath;
    }

    /**
     * //适配api11-api18,根据uri获取图片的绝对路径。
     * 针对图片URI格式为Uri:: content://media/external/images/media/1028
     */
    private static String getRealPathFromUri_Api11To18(Context context, Uri uri) {
        String filePath = null;
        String[] projection = { MediaStore.Images.Media.DATA };

        CursorLoader loader = new CursorLoader(context, uri, projection, null,
                null, null);
        Cursor cursor = loader.loadInBackground();

        if (cursor != null) {
            cursor.moveToFirst();
            filePath = cursor.getString(cursor.getColumnIndex(projection[0]));
            cursor.close();
        }
        return filePath;
    }

    /**
     * 适配api11以下(不包括api11),根据uri获取图片的绝对路径
     */
    private static String getRealPathFromUri_BelowApi11(Context context, Uri uri) {
        String filePath = null;
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = context.getContentResolver().query(uri, projection,
                null, null, null);
        if (cursor != null) {
            cursor.moveToFirst();
            filePath = cursor.getString(cursor.getColumnIndex(projection[0]));
            cursor.close();
        }
        return filePath;
    }


    /**
     * 将图片转换成Base64编码
     * @param path 待处理图片
     * @return
     */

    public static String getImgStr(String path) {
        //将图片文件转化为字节数组字符串，并对其进行Base64编码处理
        //imgFile = "D:\\testPhoto.jpg";
        if(TextUtils.isEmpty(path)){
            return null;
        }
        InputStream is = null;
        byte[] data = null;
        String result = null;
        try{
            is = new FileInputStream(path);
            //创建一个字符流大小的数组。
            data = new byte[is.available()];
            //写入数组
            is.read(data);
            //用默认的编码格式进行编码
            result = Base64.encodeToString(data,Base64.DEFAULT);
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if(null !=is){
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return result;
    }

    public static String bitmapToBase64(Bitmap bitmap) {

        String result = null;
        ByteArrayOutputStream baos = null;
        try {
            if (bitmap != null) {
                baos = new ByteArrayOutputStream();
                bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);

                baos.flush();
                baos.close();

                byte[] bitmapBytes = baos.toByteArray();
                result = Base64.encodeToString(bitmapBytes, Base64.DEFAULT);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (baos != null) {
                    baos.flush();
                    baos.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }


}

 <string name="tips_crema">当前App需要申请读写文件和调用相机权限才能运行</string>
    <string name="tips_limit">权限申请</string>
    <string name="tips_limit_true">确认</string>
    <string name="tips_limit_false">取消</string>
    <string name="tips_limit_crema">当前App需要申请读写文件和调用相机权限,需要打开设置页面么?</string>