Android初級開發（八）——手機多媒體—彈窗選擇照片或直接拍照的實現

一、效果圖
實現的功能主要是主頁一個Button,點擊後彈出選擇框，選擇拍照還是從相冊選取照片，不管哪種方式，最後將照片返回到主頁面上顯示出來。

二、實現
1、activity_main.xml佈局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <LinearLayout
        android:id="@+id/btn_layout"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/btn"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Choose picture" />


    </LinearLayout>

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

</RelativeLayout>

2、創建一個圖片的工具類，我這裏用的是別人封裝好的，如果以後對圖片進行操作，可以直接調用
ImageTools.java

/**
 * Tools for handler picture
 *
 * 
 */
public final class ImageTools {

    /**
     * Transfer drawable to bitmap
     * 
     * @param drawable
     * @return
     */
    public static Bitmap drawableToBitmap(Drawable drawable) {
        int w = drawable.getIntrinsicWidth();
        int h = drawable.getIntrinsicHeight();

        Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                : Bitmap.Config.RGB_565;
        Bitmap bitmap = Bitmap.createBitmap(w, h, config);
        Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, w, h);
        drawable.draw(canvas);
        return bitmap;
    }

    /**
     * Bitmap to drawable
     * 
     * @param bitmap
     * @return
     */
    public static Drawable bitmapToDrawable(Bitmap bitmap) {
        return new BitmapDrawable(bitmap);
    }

    /**
     * Input stream to bitmap
     * 
     * @param inputStream
     * @return
     * @throws Exception
     */
    public static Bitmap inputStreamToBitmap(InputStream inputStream)
            throws Exception {
        return BitmapFactory.decodeStream(inputStream);
    }

    /**
     * Byte transfer to bitmap
     * 
     * @param byteArray
     * @return
     */
    public static Bitmap byteToBitmap(byte[] byteArray) {
        if (byteArray.length != 0) {
            return BitmapFactory
                    .decodeByteArray(byteArray, 0, byteArray.length);
        } else {
            return null;
        }
    }

    /**
     * Byte transfer to drawable
     * 
     * @param byteArray
     * @return
     */
    public static Drawable byteToDrawable(byte[] byteArray) {
        ByteArrayInputStream ins = null;
        if (byteArray != null) {
            ins = new ByteArrayInputStream(byteArray);
        }
        return Drawable.createFromStream(ins, null);
    }

    /**
     * Bitmap transfer to bytes
     *
     * @return
     */
    public static byte[] bitmapToBytes(Bitmap bm) {
        byte[] bytes = null;
        if (bm != null) {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
            bytes = baos.toByteArray();
        }
        return bytes;
    }

    /**
     * Drawable transfer to bytes
     * 
     * @param drawable
     * @return
     */
    public static byte[] drawableToBytes(Drawable drawable) {
        BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
        Bitmap bitmap = bitmapDrawable.getBitmap();
        byte[] bytes = bitmapToBytes(bitmap);
        ;
        return bytes;
    }

    /**
     * Base64 to byte[]
//   */
//  public static byte[] base64ToBytes(String base64) throws IOException {
//      byte[] bytes = Base64.decode(base64);
//      return bytes;
//  }
//
//  /**
//   * Byte[] to base64
//   */
//  public static String bytesTobase64(byte[] bytes) {
//      String base64 = Base64.encode(bytes);
//      return base64;
//  }

    /**
     * Create reflection images
     * 
     * @param bitmap
     * @return
     */
    public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap) {
        final int reflectionGap = 4;
        int w = bitmap.getWidth();
        int h = bitmap.getHeight();

        Matrix matrix = new Matrix();
        matrix.preScale(1, -1);

        Bitmap reflectionImage = Bitmap.createBitmap(bitmap, 0, h / 2, w,
                h / 2, matrix, false);

        Bitmap bitmapWithReflection = Bitmap.createBitmap(w, (h + h / 2),
                Config.ARGB_8888);

        Canvas canvas = new Canvas(bitmapWithReflection);
        canvas.drawBitmap(bitmap, 0, 0, null);
        Paint deafalutPaint = new Paint();
        canvas.drawRect(0, h, w, h + reflectionGap, deafalutPaint);

        canvas.drawBitmap(reflectionImage, 0, h + reflectionGap, null);

        Paint paint = new Paint();
        LinearGradient shader = new LinearGradient(0, bitmap.getHeight(), 0,
                bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff,
                0x00ffffff, TileMode.CLAMP);
        paint.setShader(shader);
        // Set the Transfer mode to be porter duff and destination in
        paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
        // Draw a rectangle using the paint with our linear gradient
        canvas.drawRect(0, h, w, bitmapWithReflection.getHeight()
                + reflectionGap, paint);

        return bitmapWithReflection;
    }

    /**
     * Get rounded corner images
     * 
     * @param bitmap
     * @param roundPx
     *            5 10
     * @return
     */
    public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, float roundPx) {
        int w = bitmap.getWidth();
        int h = bitmap.getHeight();
        Bitmap output = Bitmap.createBitmap(w, h, Config.ARGB_8888);
        Canvas canvas = new Canvas(output);
        final int color = 0xff424242;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, w, h);
        final RectF rectF = new RectF(rect);
        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);

        return output;
    }

    /**
     * 縮小圖片
     * 
     * @param bitmap
     * @param width
     * @param height
     * @return
     */
    public static Bitmap zoomBitmap(Bitmap bitmap, int width, int height) {
        int w = bitmap.getWidth();
        int h = bitmap.getHeight();
        Matrix matrix = new Matrix();
        float scaleWidth = ((float) width / w);
        float scaleHeight = ((float) height / h);
        matrix.postScale(scaleWidth, scaleHeight);
        Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix, true);
        return newbmp;
    }

    /**
     * Resize the drawable
     * @param drawable
     * @param w
     * @param h
     * @return
     */
    public static Drawable zoomDrawable(Drawable drawable, int w, int h) {
        int width = drawable.getIntrinsicWidth();
        int height = drawable.getIntrinsicHeight();
        Bitmap oldbmp = drawableToBitmap(drawable);
        Matrix matrix = new Matrix();
        float sx = ((float) w / width);
        float sy = ((float) h / height);
        matrix.postScale(sx, sy);
        Bitmap newbmp = Bitmap.createBitmap(oldbmp, 0, 0, width, height,
                matrix, true);
        return new BitmapDrawable(newbmp);
    }

    /**
     * Get images from SD card by path and the name of image
     * @param photoName
     * @return
     */
    public static Bitmap getPhotoFromSDCard(String path,String photoName){
        Bitmap photoBitmap = BitmapFactory.decodeFile(path + "/" +photoName +".png");
        if (photoBitmap == null) {
            return null;
        }else {
            return photoBitmap;
        }
    }

    /**
     * Check the SD card 
     * @return
     */
    public static boolean checkSDCardAvailable(){
        return android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);
    }

    /**
     * Get image from SD card by path and the name of image
     * @return
     */
    public static boolean findPhotoFromSDCard(String path,String photoName){
        boolean flag = false;

        if (checkSDCardAvailable()) {
            File dir = new File(path);
            if (dir.exists()) {
                File folders = new File(path);
                File photoFile[] = folders.listFiles();
                for (int i = 0; i < photoFile.length; i++) {
                    String fileName = photoFile[i].getName().split("\\.")[0];
                    if (fileName.equals(photoName)) {
                        flag = true;
                    }
                }
            }else {
                flag = false;
            }
//          File file = new File(path + "/" + photoName  + ".jpg" );
//          if (file.exists()) {
//              flag = true;
//          }else {
//              flag = false;
//          }

        }else {
            flag = false;
        }
        return flag;
    }


    /**
     * 將圖片保存到本地SD卡
     * @param photoBitmap
     * @param photoName
     * @param path
     */
    public static void savePhotoToSDCard(Bitmap photoBitmap,String path,String photoName){
        if (checkSDCardAvailable()) {
            File dir = new File(path);
            if (!dir.exists()){
                dir.mkdirs();
            }

            File photoFile = new File(path , photoName + ".png");
            FileOutputStream fileOutputStream = null;
            try {
                fileOutputStream = new FileOutputStream(photoFile);
                if (photoBitmap != null) {
                    if (photoBitmap.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream)) {
                        fileOutputStream.flush();
//                      fileOutputStream.close();
                    }
                }
            } catch (FileNotFoundException e) {
                photoFile.delete();
                e.printStackTrace();
            } catch (IOException e) {
                photoFile.delete();
                e.printStackTrace();
            } finally{
                try {
                    fileOutputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        } 
    }


    /**
     * Delete the image from SD card
     * @param path
     * file:///sdcard/temp.jpg
     */
    public static void deleteAllPhoto(String path){
        if (checkSDCardAvailable()) {
            File folder = new File(path);
            File[] files = folder.listFiles();
            for (int i = 0; i < files.length; i++) {
                files[i].delete();
            }
        }
    }

    //刪除上一次截圖的臨時文件，包括圖片路徑和文件名稱
    public static void deletePhotoAtPathAndName(String path,String fileName){
        if (checkSDCardAvailable()) {
            File folder = new File(path);
            File[] files = folder.listFiles();
            for (int i = 0; i < files.length; i++) {
                System.out.println(files[i].getName());
                if (files[i].getName().equals(fileName)) {
                    files[i].delete();
                }
            }
        }
    }

}

3、MainActivity.java

public class MainActivity extends Activity {

    private static final int TAKE_PICTURE = 0;  //拍照
    private static final int CHOOSE_PICTURE = 1;  //從相冊中選擇照片
    private static final int CROP = 2;
    private static final int CROP_PICTURE = 3;

    private static final int SCALE = 5;//照片縮小比例
    private ImageView iv_image = null;

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

        iv_image = (ImageView) this.findViewById(R.id.img);

        this.findViewById(R.id.btn).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                //彈出對話框，選擇要直接拍照還是從相冊中選擇照片
                showPicturePicker(MainActivity.this,false);
            }
        });
    }




    //彈出Dialog選擇窗口
    public void showPicturePicker(Context context,boolean isCrop){
        final boolean crop = isCrop;
        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        //設置彈出框標題
        builder.setTitle("圖片來源");
        builder.setNegativeButton("取消", null);
        builder.setItems(new String[]{"拍照","相冊"}, new DialogInterface.OnClickListener() {
            //類型碼
            int REQUEST_CODE;

            @Override
            public void onClick(DialogInterface dialog, int which) {
                switch (which) {
                case TAKE_PICTURE:
                    Uri imageUri = null;
                    String fileName = null;
                    //發送啓動相機程序請求
                    Intent openCameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                    if (crop) {
                        REQUEST_CODE = CROP;
                        //刪除上一次截圖的臨時文件
                        SharedPreferences sharedPreferences = getSharedPreferences("temp",Context.MODE_WORLD_WRITEABLE);
                        ImageTools.deletePhotoAtPathAndName(Environment.getExternalStorageDirectory().getAbsolutePath(), sharedPreferences.getString("tempName", ""));

                        //保存本次截圖臨時文件名字
                        fileName = String.valueOf(System.currentTimeMillis()) + ".jpg";
                        Editor editor = sharedPreferences.edit();
                        editor.putString("tempName", fileName);
                        editor.commit();
                    }else {
                        REQUEST_CODE = TAKE_PICTURE;
                        fileName = "image.jpg";
                    }
                    //從文件中創建URI
                    imageUri = Uri.fromFile(new File(Environment.getExternalStorageDirectory(),fileName));
                    //指定照片保存路徑（SD卡），image.jpg爲一個臨時文件，每次拍照後這個圖片都會被替換
                    openCameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                    //開啓一個帶有返回值的Activity，請求嗎爲REQUEST_CODE
                    startActivityForResult(openCameraIntent, REQUEST_CODE);
                    break;

                case CHOOSE_PICTURE:
                    //發送打開相冊程序器請求
                    Intent openAlbumIntent = new Intent(Intent.ACTION_GET_CONTENT);
                    if (crop) {
                        REQUEST_CODE = CROP;
                    }else {
                        REQUEST_CODE = CHOOSE_PICTURE;
                    }
                    openAlbumIntent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");
                    startActivityForResult(openAlbumIntent, REQUEST_CODE);
                    break;

                default:
                    break;
                }
            }
        });
        builder.create().show();
    }

    //截取圖片
    public void cropImage(Uri uri, int outputX, int outputY, int requestCode){
        Intent intent = new Intent("com.android.camera.action.CROP");  
        intent.setDataAndType(uri, "image/*");  
        intent.putExtra("crop", "true");  
        intent.putExtra("aspectX", 1);  
        intent.putExtra("aspectY", 1);  
        intent.putExtra("outputX", outputX);   
        intent.putExtra("outputY", outputY); 
        intent.putExtra("outputFormat", "JPEG");
        intent.putExtra("noFaceDetection", true);
        intent.putExtra("return-data", true);  
        startActivityForResult(intent, requestCode);
    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == RESULT_OK) {
            switch (requestCode) {
                case TAKE_PICTURE:
                    //將保存在本地的圖片取出並縮小後顯示在界面上
                    Bitmap bitmap = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory()+"/image.jpg");
                    Bitmap newBitmap = ImageTools.zoomBitmap(bitmap, bitmap.getWidth() / SCALE, bitmap.getHeight() / SCALE);
                    //由於Bitmap內存佔用較大，這裏需要回收內存，否則會報out of memory異常
                    bitmap.recycle();

                    //將處理過的圖片顯示在界面上，並保存到本地
                    iv_image.setImageBitmap(newBitmap);
                    ImageTools.savePhotoToSDCard(newBitmap, Environment.getExternalStorageDirectory().getAbsolutePath(), String.valueOf(System.currentTimeMillis()));

                    break;

                case CHOOSE_PICTURE:
                    ContentResolver resolver = getContentResolver();
                    //照片的原始資源地址
                    Uri originalUri = data.getData();
                    try {
                        //使用ContentProvider通過URI獲取原始圖片
                        Bitmap photo = MediaStore.Images.Media.getBitmap(resolver, originalUri);
                        if (photo != null) {
                            //爲防止原始圖片過大導致內存溢出，這裏先縮小原圖顯示，然後釋放原始Bitmap佔用的內存
                            Bitmap smallBitmap = ImageTools.zoomBitmap(photo, photo.getWidth() / SCALE, photo.getHeight() / SCALE);
                            //釋放原始圖片佔用的內存，防止out of memory異常發生
                            photo.recycle();

                            iv_image.setImageBitmap(smallBitmap);
                        }
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    break;

                case CROP:
                    Uri uri = null;
                    if (data != null) {
                        uri = data.getData();
                        System.out.println("Data");
                    }else {
                        System.out.println("File");
                        String fileName = getSharedPreferences("temp",Context.MODE_WORLD_WRITEABLE).getString("tempName", "");
                        uri = Uri.fromFile(new File(Environment.getExternalStorageDirectory(),fileName));
                    }
                    cropImage(uri, 500, 500, CROP_PICTURE);
                    break;

                case CROP_PICTURE:
                    Bitmap photo = null;
                    Uri photoUri = data.getData();
                    if (photoUri != null) {
                        photo = BitmapFactory.decodeFile(photoUri.getPath());
                    }
                    if (photo == null) {
                        Bundle extra = data.getExtras();
                        if (extra != null) {
                            photo = (Bitmap)extra.get("data");
                            ByteArrayOutputStream stream = new ByteArrayOutputStream();
                            photo.compress(Bitmap.CompressFormat.JPEG, 100, stream);
                        }
                    }
                    iv_image.setImageBitmap(photo);
                    break;
                default:
                    break;
            }
        }
    }
}

4、修改AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.ryantang.picture"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <uses-feature android:name="android.hardware.camera" />
    <uses-feature android:name="android.hardware.camera.autofocus" />


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

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.ryantang.picture.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

上面的代碼是借鑑別人的，我之前沒考慮到用Dialog。之前做的是仿微信的底部彈窗，用的是popupwindow，遇到的問題是我們創建了一個popupwindow活動，在活動中監聽按鈕進入圖片或者相機，這樣最後得到的圖片返回到popupwindow，並沒有傳到MainActivity。我嘗試過將圖片bitmap傳到MainActivity，或者圖片URI傳過去，也嘗試用startActivityForResult傳值，都沒有成功，，，問題可能還是對於三個問題理解不深入：1、對於文件存儲和讀取的理解；2、對於一個Activity傳值給另一個Activity，或者說一個Activity控制另一個Activity的UI更新；3、對與startActivityForResult和onActivityResult的理解。。。。繼續努力吧！！！