Android编程实现压缩图片并加载显示的方法

options.inSampleSize = scale;

/** * 压缩图片 * @author chen.lin * */public class LoadImageActivity extends Activity implements OnClickListener {  private Button mBtnLoad;  private ImageView mImageView;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_image_load);    initViews();  }  private void initViews() {    mBtnLoad = (Button) findViewById(R.id.btnLoadImage);    mImageView = (ImageView) findViewById(R.id.imageView);    mBtnLoad.setOnClickListener(this);  }  @Override  public void onClick(View v) {    if (v == mBtnLoad) {      Options options = new Options();      BitmapFactory.decodeFile("/sdcard/images/1.jpg", options);      //不去真的解析图片，只是获取图片的头部信息，宽高      options.inJustDecodeBounds = true;      //得到图片的真实宽高      int imageHeight = options.outHeight;      int imageWidth = options.outWidth;      //得到屏幕的宽高      WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);      int screenHeight = wm.getDefaultDisplay().getHeight();      int screenWidth = wm.getDefaultDisplay().getWidth();      //得到缩放比例      int scale = 1;      int scaleX = imageWidth / screenWidth;      int scaleY = imageHeight / screenHeight;      if (scaleX > scaleY & scaleX >=1) {//表示如果宽的缩放比例大于高的，并且scaleX>=1都为true        scale = scaleX;      }      if (scaleY > scaleX & scaleY >=1) {//表示如果高的缩放比例大于宽的，并且scaleY>=1都为true        scale = scaleY;      }      //解析图片      options.inJustDecodeBounds = false;      //修改图片的缩放比例，如果scale=4说明图片缩小4倍，像数=1/16      options.inSampleSize = scale;      Bitmap bm = BitmapFactory.decodeFile("/sdcard/images/1.jpg", options);      mImageView.setImageBitmap(bm);    }  }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical" >  <ImageView    android:id="@+id/imageView"    android:layout_width="fill_parent"    android:layout_height="0dp"    android:layout_weight="1" />  <EditText    android:id="@+id/editText1"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:ems="10" >    <requestFocus />  </EditText>  <Button    android:id="@+id/btnLoadImage"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:onClick="loadImage"    android:text="加载图片" /></LinearLayout>