/**
  * 
  * 利用给定路径下的图片设置ImageView
  * 
  * @param imgPath 手机图片文件路径
  * @param imgView 需要设置的ImageView
  */
public void setImg(String imgPath, ImageView imgView) {
  File file = new File(imgPath);
  if (file.exists() && file.canRead()) {
   // -------1.图片缩放--------

   // 手机屏幕信息
   DisplayMetrics metric = new DisplayMetrics();
   getWindowManager().getDefaultDisplay().getMetrics(metric);
   int dw = metric.widthPixels; // 屏幕宽
   int dh = metric.heightPixels; // 屏幕高

   // 加载图像，只是为了获取尺寸
   BitmapFactory.Options options = new BitmapFactory.Options();
   options.inJustDecodeBounds = true; // 设置之后可以获取尺寸信息
   Bitmap bitmap = BitmapFactory.decodeFile(imgPath, options);
   // 计算水平和垂直缩放系数
   int heightRatio = (int) Math.ceil(options.outHeight / (float) dh);
   int widthRatio = (int) Math.ceil(options.outWidth / (float) dw);
   // 判断哪个大
   if (heightRatio > 1 && widthRatio > 1) {
    if (heightRatio > widthRatio) {
     options.inSampleSize = heightRatio;
    } else {
     options.inSampleSize = widthRatio;
    }
   }
   // 图片缩放
   options.inJustDecodeBounds = false;
   bitmap = BitmapFactory.decodeFile(imgPath, options);

   // -------2.判断图片朝向--------
   try {
    ExifInterface exif = new ExifInterface(imgPath);
    int degree = 0; // 图片旋转角度
    if (exif != null) {
     int orientation = exif.getAttributeInt(
       ExifInterface.TAG_ORIENTATION, -1);
     if (orientation != -1) {
      switch (orientation) {
      case ExifInterface.ORIENTATION_ROTATE_90:
       degree = 90;
       break;

      case ExifInterface.ORIENTATION_ROTATE_180:
       degree = 180;
       break;

      case ExifInterface.ORIENTATION_ROTATE_270:
       degree = 270;
       break;
      default:
       break;
      }
     }
    }

    if (degree != 0) { // 图片需要旋转
     int width = bitmap.getWidth();
     int height = bitmap.getHeight();
     Matrix matrix = new Matrix();
     matrix.preRotate(degree);
     Bitmap mRotateBitmap = Bitmap.createBitmap(bitmap, 0, 0,
       width, height, matrix, true);

     imgView.setImageBitmap(mRotateBitmap);
    } else {
     imgView.setImageBitmap(bitmap);
    }
   } catch (IOException e) {
   }
  }
 }