从相册中选择图片进行压缩并用ImageView展示出来，,从手机中选择照片这是几乎

从相册中选择图片进行压缩并用ImageView展示出来，,从手机中选择照片这是几乎

从手机中选择照片这是几乎所有应用的功能之一，主要考虑到一点的就是如果图片太大了，可能会OOM，简单的处理就是对图片进行压缩！

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <Button android:id="@+id/photo_btn" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="选择照片" /> <ImageView android:id="@+id/photo_iv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:contentDescription="选择自己相册照片" android:layout_gravity="center" android:layout_marginTop="10dp"/></LinearLayout>

-----------操作代码--------------

public class PhotoActivity extends Activity {/点击选择照片按钮*/private Button photoBtn;/选择后展示照片/private ImageView photoIv;/请求码*/private final static int SELECT_PHOTO_CODE = 100;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.activity_photo);initViews();initListners();}private void initViews() {photoBtn = (Button) findViewById(R.id.photo_btn);photoIv = (ImageView) findViewById(R.id.photo_iv);}private void initListners() {photoBtn.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {selectPhotoFromAblum();}});}/从相册库中选择图片操作/private void selectPhotoFromAblum() {Intent intent = new Intent(Intent.ACTION_PICK, null);intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/");startActivityForResult(intent, SELECT_PHOTO_CODE);}@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {switch (requestCode) {case SELECT_PHOTO_CODE:if (null != data) {/取得图片，图片压缩比为44/Bitmap bm = compressBitmap(null, null, this, data.getData(), 4, false);photoIv.setImageBitmap(bm);}break;default:break;}super.onActivityResult(requestCode, resultCode, data);}/图片压缩处理，size参数为压缩比，比如size为2，则压缩为1/4/private Bitmap compressBitmap(String path, byte[] data, Context context, Uri uri, int size, boolean width) {Options options = null;if (size > 0) {Options info = new Options();/如果设置true的时候，decode时候Bitmap返回的为数据将空/info.inJustDecodeBounds = false;decodeBitmap(path, data, context, uri, info);int dim = info.outWidth;if (!width) dim = Math.max(dim, info.outHeight);options = new Options();/把图片宽高读取放在Options里*/options.inSampleSize = size;}Bitmap bm = null;try {bm = decodeBitmap(path, data, context, uri, options);}catch (Exception e) {e.printStackTrace();}return bm;}/把byte数据解析成图片*/private Bitmap decodeBitmap(String path, byte[] data, Context context, Uri uri, BitmapFactory.Options options) {Bitmap result = null;if (path != null) {result = BitmapFactory.decodeFile(path, options);}else if (data != null) {result = BitmapFactory.decodeByteArray(data, 0, data.length, options);}else if (uri != null) {ContentResolver cr = context.getContentResolver();InputStream inputStream = null;try {inputStream = cr.openInputStream(uri);result = BitmapFactory.decodeStream(inputStream, null, options);inputStream.close();}catch (Exception e) {e.printStackTrace();}}return result;}}

最后注意权限： <!-- 从SDCard读取数据权限--> <uses-permissionandroid:name="android.permission.READ_EXTERNAL_STORAGE"/>