android判断相机图片朝向的简单方法

/**
	 * 
	 * 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) {
			}
		}
	}