封装了一个类，让你用几代码就能获得相册或拍照得到的图片

一、最终成果

本例是用android自带的相册获取图片的，并且处理了很多异常，最终你的activity只需要用很少的代码就能获得用户选择好的图片了。

例子：

 　　<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

加完权限后就可以编码啦~

package com.example.jack.getphoto;

import com.kale.lib.activity.KaleBaseActivity;
import com.kale.lib.photo.GetSimplePhotoHelper;
import com.kale.lib.photo.SimplePhoto;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

/**
 * @author Jack Tony
 *         <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 *         <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
 * @date 2015/4/26
 */
public class MainActivity extends KaleBaseActivity implements View.OnClickListener {

    private ImageView photoImageView;

    private Button fromAlbumButton;

    private Button fromCameraButton;

    GetSimplePhotoHelper mPhotoHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mPhotoHelper = GetSimplePhotoHelper.getInstance(this);
    }

    protected void findViews() {
        photoImageView = getView(R.id.photo_imageView);
        fromAlbumButton = getView(R.id.fromAlbum_button);
        fromCameraButton = getView(R.id.fromCamera_button);
        photoImageView = getView(R.id.photo_imageView);
    }

    @Override
    protected void beforeSetViews() {
        
    }

    @Override
    protected void setViews() {
        fromAlbumButton.setOnClickListener(this);
        fromCameraButton.setOnClickListener(this);
    }

    @Override
    protected int getContentViewId() {
        return R.layout.activity_main;
    }

    @Override
    public void onClick(View v) {
        if (v == fromAlbumButton) {
            // Handle clicks for fromAlbumButton
            // 去选择图片，photo的路径设置为null就好
            mPhotoHelper.choicePhoto(GetSimplePhotoHelper.FROM_ALBUM, null,new MyListener());
        } else if (v == fromCameraButton) {
            // Handle clicks for fromCameraButton
            mPhotoHelper.choicePhoto(GetSimplePhotoHelper.FROM_CAMERA, null,new MyListener());
            // 可以设置拍照后图片图片保存的自定义路径，如果不设置路径，那么拍照后的照片不会保存在sd卡中
            //mPhotoHelper.choicePhoto(GetSimplePhotoHelper.FROM_WAY.FROM_CAMERA, Environment.getExternalStorageDirectory()+ "/my_temp.jpg");
        }
    }
    
    class MyListener implements GetSimplePhotoHelper.OnSelectedPhotoListener {


        @Override
        public void onSelectedPhoto(int fromWay, SimplePhoto photo) {
            if (photo != null) {
                photoImageView.setImageBitmap(photo.bitmap);
                Log.d(TAG, "uri = " + photo.uri.toString());
                Log.d(TAG, "photo's degree = " + photo.degree);
            }
        }
    }

    
}

很简单吧，那么下面我们来看看如何实现这个功能。

二、GetSimplePhotoHelper

package com.kale.lib.photo;


import com.kale.lib.utils.BitmapUtil;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.support.annotation.IntDef;

import java.io.File;

/**
 * @author Jack Tony
 *         从相册或者从照相机得到一个图片，没有裁剪功能
 * @date 2015/4/24
 */
public class GetSimplePhotoHelper {

    public static final int FROM_ALBUM = 0;

    public static final int FROM_CAMERA = 1;

    @IntDef({GetSimplePhotoHelper.FROM_ALBUM, GetSimplePhotoHelper.FROM_CAMERA})
    private @interface from {

    }

    private Activity mActivity;

    private String mPicFilePath;

    private int mFromWay;

    private GetSimplePhotoHelper(Activity activity) {
        mActivity = activity;
    }

    private static GetSimplePhotoHelper instance;

    public static GetSimplePhotoHelper getInstance(Activity activity) {
        if (instance == null) {
            instance = new GetSimplePhotoHelper(activity);
        }
        return instance;
    }

    /**
     * 从相册或照相机获得一张图片
     *
     * @param way         获取图片的途径
     * @param picFilePath 如果需要保存从相机拍摄的图片，请指定保存图片的全部路径(通过相机拍照时才有效)
     *                    eg:GetPhotoHelper.choicePhoto(GetPhotoHelper.FROM_WAY.FROM_CAMERA, Environment.getExternalStorageDirectory()+ "/temp.jpg");
     */
    public void choicePhoto(@from final int way, String picFilePath, OnSelectedPhotoListener listener) {
        mFromWay = way;
        mPicFilePath = picFilePath;
        if (way == FROM_ALBUM) {
            choicePhotoFromAlbum();
        } else if (way == FROM_CAMERA) {
            choicePhotoFromCamera(picFilePath);
        }
        mListener = listener;
    }

    /**
     * 启动相册的activity
     */
    private void choicePhotoFromAlbum() {
        Intent intent = new Intent(mActivity, GetSimplePhotoActivity.class);
        intent.putExtra(GetSimplePhotoActivity.KEY_FROM_WAY, GetSimplePhotoActivity.VALUE_FROM_ALBUM);
        mActivity.startActivityForResult(intent, 0);
    }

    /**
     * 启动相机的activity
     */
    private void choicePhotoFromCamera(String picFilePath) {
        Intent intent = new Intent(mActivity, GetSimplePhotoActivity.class);
        intent.putExtra(GetSimplePhotoActivity.KEY_FROM_WAY, GetSimplePhotoActivity.VALUE_FROM_CAMERA);
        intent.putExtra(GetSimplePhotoActivity.KEY_PHOTO_PATH, picFilePath);
        mActivity.startActivityForResult(intent, 0);
    }


    /**
     * 得到已经选择好的图片，这个方法必须在onActivityResult中进行回调
     *
     * @return 已经选择好的bitmap
     */
    protected void getSelectedPhoto(Uri uri) {
        //Logger.d("uri = " + uri);
        Bitmap bitmap = BitmapFactory.decodeFile(uri.toString());
        // Logger.d("方向 =" + GetSimplePhotoUtil.getOrientation(uri));
        if (bitmap != null) {
            bitmap = BitmapUtil.rotateBitmap(bitmap, GetSimplePhotoUtil.getPhotoDegreeByUri(uri));
        }
        SimplePhoto photo = new SimplePhoto();
        photo.bitmap = bitmap;
        photo.uri = uri;
        photo.degree = GetSimplePhotoUtil.getPhotoDegreeByUri(uri);

        // 如果来源是相机，而且没有指定图片保存的目录，那么使用完毕后就立刻删除相片
        if (mFromWay == FROM_CAMERA && mPicFilePath == null) {
            File tempPicFile = new File(uri.toString());
            if (tempPicFile != null) {
                tempPicFile.delete();//设置成功后清除之前的照片文件
            }
        }
        mListener.onSelectedPhoto(mFromWay,photo);
    }

    private OnSelectedPhotoListener mListener;

    public interface OnSelectedPhotoListener {

        public void onSelectedPhoto(int way,SimplePhoto photo);

    }

}

这个类主要是获得activity并且获得用户期望获取图片的途径，并且告诉GetSimplePhotoActivity（真正的处理类）。如果是想通过相机获取图片，那么这里还可以指定拍摄的照片保存的路径，不设置就不保存照片。最后，它还处理了照片返回的结果，判断照片的方向，进行正确的旋转产生最终的bitmap。总之，这个类做的是获得用户获取图片的途径，之后启动activity来进行处理。在处理结束后，它进行结果的解析，最终返回一个SimplePhoto对象。

三、GetSimplePhotoActivity

GetSimplePhotoActivity是真正的处理类，用来启动系统相册或者是系统相机来获取图片。在启动系统相册的时候需要有个版本判断，在高版本上获得的uri可能会有点问题，所以这里需要判断不同的版本，进行不同的处理。同时，它还应该对于获得的图片进行回调，返回一个uri。

package com.kale.lib.photo;


import com.kale.lib.utils.IntentUtil;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;

import java.io.File;

/**
 * @author Jack Tony
 * @date 2015/4/24
 */
public class GetSimplePhotoActivity extends Activity {

    private class RequestCode {

        public static final int ALBUM_OK = 1, ALBUM_OK_KITKAT = 2, CAMERA_OK = 3;
    }

    /**
     * 准备通过什么样的方式来获取图片
     */
    public static final String KEY_FROM_WAY = "key_from_way";

    /**
     * 图片的全部路径
     */
    public static final String KEY_PHOTO_PATH = "key_photo_path";


    public static final int VALUE_FROM_ALBUM = 54345;

    public static final int VALUE_FROM_CAMERA = 46632;

    public static final String TEMP_PHOTO_FILE_NAME = "kale_temp_photo.jpg";

    private File tempPicFile;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (!IntentUtil.isBundleEmpty(getIntent())) {
            Bundle bundle = getIntent().getExtras();
            if (bundle.getInt(KEY_FROM_WAY, VALUE_FROM_ALBUM) == VALUE_FROM_ALBUM) {
                // 进行版本判断 see:http://blog.csdn.net/tempersitu/article/details/20557383
                if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
                    GetSimplePhotoUtil.choicePicFromAlbum_kitkat(this, RequestCode.ALBUM_OK_KITKAT);
                } else {
                    // 4.4以下
                    GetSimplePhotoUtil.choicePicFromAlbum(this, RequestCode.ALBUM_OK);
                }
            } else {
                if (bundle.getString(KEY_PHOTO_PATH) == null) {
                    // 照相得到的图片默认的保存路径，用完后会自动删除
                    tempPicFile = new File(Environment.getExternalStorageDirectory(), TEMP_PHOTO_FILE_NAME);
                } else {
                    // 自定义照相得到的图片的保存路径，不会自动删除
                    tempPicFile = new File(bundle.getString(KEY_PHOTO_PATH));
                }
                tempPicFile.delete();// 清空之前的文件
                GetSimplePhotoUtil.choicePicFromCamera(this, tempPicFile, RequestCode.CAMERA_OK);
            }
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Uri uri;
        switch (requestCode) {
            // 如果是直接从相册获取
            case RequestCode.ALBUM_OK:
                //从相册中获取到图片
                if (data != null) {
                    uri = data.getData();
                    finishAndReturnBitmap(uri);
                } else {
                    finish();
                }
                break;
            case RequestCode.ALBUM_OK_KITKAT:
                if (data != null) {
                    uri = Uri.parse(GetSimplePhotoUtil.getPath(this, data.getData()));
                    finishAndReturnBitmap(uri);
                } else {
                    finish();
                }
                break;
            // 如果是调用相机拍照时
            case RequestCode.CAMERA_OK:
                // 当拍照到照片时操作
                if (tempPicFile.exists()) {
                    uri = Uri.parse(tempPicFile.getAbsolutePath());
                    finishAndReturnBitmap(uri);
                } else {
                    finish();
                }
                break;
            default:
                break;
        }
    }

    public void finishAndReturnBitmap(Uri uri) {
        GetSimplePhotoHelper.getInstance(this).getSelectedPhoto(uri);
        finish();
    }
}

四、工具类和模型类

GetSimplePhotoUtil

package com.kale.lib.photo;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.ContentUris;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.media.ExifInterface;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;

import java.io.File;
import java.io.IOException;

/**
 * @author Jack Tony
 * @brief
 * @date 2015/4/25
 */
class GetSimplePhotoUtil {

    /**
     * 从相册获取图片
     */
    public static void choicePicFromAlbum(Activity activity, int requestCode) {
        // 来自相册
        Intent albumIntent = new Intent(Intent.ACTION_GET_CONTENT);
        albumIntent.addCategory(Intent.CATEGORY_OPENABLE);
        albumIntent.setType("image/*");
        activity.startActivityForResult(albumIntent, requestCode);
    }

    /**
     * 4.4以上版本使用
     * @see "http://blog.csdn.net/tempersitu/article/details/20557383"
     * 
     * @param activity
     * @param requestCode
     */
    public static void choicePicFromAlbum_kitkat(Activity activity, int requestCode) {
        // 来自相册
        Intent albumIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
        albumIntent.addCategory(Intent.CATEGORY_OPENABLE);
        albumIntent.setType("image/*");
        activity.startActivityForResult(albumIntent, requestCode);
    }

    /**
     * 拍照后获取图片
     *
     * @param activity           
     * @param cameraPhotoFile 照片的文件
     * @param requestCode
     */
    public static void choicePicFromCamera(Activity activity, File cameraPhotoFile,int requestCode) {
        // 来自相机
        Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        // 下面这句指定调用相机拍照后的照片存储的路径，这样通过这个uri就可以得到这个照片了
        cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(cameraPhotoFile));
        activity.startActivityForResult(cameraIntent, requestCode);// CAMERA_OK是用作判断返回结果的标识
    }

    private int aspectX = 1000;

    private int aspectY = 1000;

    private int outputX = 1;

    private int outputY = 1;

    private boolean shouldBeClip = false;

    private boolean shouldBeScale = false;

    /**
     * 设置比率，比如1:1
     */
    public void setAspectX(int aspectX, int aspectY) {
        this.aspectX = aspectX;
        this.aspectY = aspectY;
    }

    /**
     * 设置裁剪出来的图片的宽高
     */
    public void setOutputX(int outputX, int outputY) {
        this.outputX = outputX;
        this.outputY = outputY;
    }


    /**
     * 裁剪时是否保留图片的比例，如果是true那么就是保留
     */
    public void setShouldBeScale(boolean shoubeScale) {
        this.shouldBeScale = shoubeScale;
    }

    /**
     * 4.4得到的uri,需要以下方法来获取文件的路径
     * 
     * @param context
     * @param uri
     * @return
     */
    @SuppressLint("NewApi")
    public static String getPath(final Context context, final Uri uri) {

        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        // DocumentProvider  
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider  
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }

                // TODO handle non-primary volumes  
            }
            // DownloadsProvider  
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(
                        Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider  
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }

                final String selection = "_id=?";
                final String[] selectionArgs = new String[] {
                        split[1]
                };

                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
        // MediaStore (and general)  
        else if ("content".equalsIgnoreCase(uri.getScheme())) {

            // Return the remote address  
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();

            return getDataColumn(context, uri, null, null);
        }
        // File  
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }

        return null;
    }

    /**
     * Get the value of the data column for this Uri. This is useful for 
     * MediaStore Uris, and other file-based ContentProviders. 
     *
     * @param context The context. 
     * @param uri The Uri to query. 
     * @param selection (Optional) Filter used in the query. 
     * @param selectionArgs (Optional) Selection arguments used in the query. 
     * @return The value of the _data column, which is typically a file path. 
     */
    private static String getDataColumn(Context context, Uri uri, String selection,
            String[] selectionArgs) {

        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = {
                column
        };

        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
                    null);
            if (cursor != null && cursor.moveToFirst()) {
                final int index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }


    /**
     * @param uri The Uri to check. 
     * @return Whether the Uri authority is ExternalStorageProvider. 
     */
    private static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check. 
     * @return Whether the Uri authority is DownloadsProvider. 
     */
    private static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check. 
     * @return Whether the Uri authority is MediaProvider. 
     */
    private static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check. 
     * @return Whether the Uri authority is Google Photos. 
     */
    private static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getAuthority());
    }

    /**
     * 得到图片的方向
     * 
     * @param photoUri    
     * @return
     */
    public static int getOrientation(final Uri photoUri) {
        ExifInterface exifInterface = null;
        try {
            exifInterface = new ExifInterface(photoUri.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
        return exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, -1);
    }

    /**
     * 通过photo的uri来得到图片的角度，从而判断是否需要进行旋转操作
     *
     * @param uri
     * @return
     */
    public static int getPhotoDegreeByUri(Uri uri) {
        int degree = 0;
        int orientation = GetSimplePhotoUtil.getOrientation(uri);
        if (orientation == ExifInterface.ORIENTATION_ROTATE_90) {
            degree = 90;
        } else if (orientation == ExifInterface.ORIENTATION_ROTATE_180) {
            degree = 180;
        } else if (orientation == ExifInterface.ORIENTATION_ROTATE_270) {
            degree = 270;
        }
        return degree;
    }

}

SimplePhoto

package com.kale.lib.photo;

import android.graphics.Bitmap;
import android.net.Uri;

/**
 * @author Jack Tony
 * @brief
 * @date 2015/4/26
 */
public class SimplePhoto {

    /**
     * 图片的uri，其实就是地址。eg:/storage/sdcard0/Tencent/QQ_Images/-1935240a504f548c.jpg
     */
    public Uri uri;

    /**
     * 图像需要旋转的角度。方向不正确的图像可以根据这个进行旋转操作
     */
    public int degree;

    /**
     * 图像的bitmap
     */
    public Bitmap bitmap;
}

五、配置文件

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.kale.lib">

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

    <application
        android:name=".KaleApplication"
        android:allowBackup="true"
        android:label="@string/app_name">
        <activity
            android:name=".photo.GetSimplePhotoActivity"
            android:theme="@android:style/Theme.Translucent" />
    </application>


</manifest>