我想根据Android中的设备方向设置相机方向，但似乎没有任何效果。我尝试旋转Surface以及相机参数，但是纵向模式下的相机预览总是颠倒过来。我需要顺时针旋转90度才能使其正确。这是我现在使用的代码，仅适用于横向模式。
SurfaceHolder.Callback surfaceCallback = new SurfaceHolder.Callback() {
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
camera.stopPreview();
camera.release();
camera = null;
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
initCamera();
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.2;
double targetRatio = (double) w / h;
if (sizes == null)
return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (Size size : sizes) {
Log.d(TAG, "Checking size " + size.width + "w " + size.height
+ "h");
double ratio = (double) size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
// Cannot find the one match the aspect ratio, ignore the
// requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Camera.Parameters parameters = camera.getParameters();
List<Size> sizes = parameters.getSupportedPreviewSizes();
Size optimalSize = getOptimalPreviewSize(sizes, width, height);
Log.d(TAG, "Surface size is " + width + "w " + height + "h");
Log.d(TAG, "Optimal size is " + optimalSize.width + "w " + optimalSize.height + "h");
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
// parameters.setPreviewSize(width, height);
camera.setParameters(parameters);
camera.startPreview();
}
};
答案 0 :(得分：71)
来自其他成员和我的问题：
相机旋转问题取决于不同的设备和某些版本。
版本1.6：修复轮换问题，对大多数设备都有好处
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT)
{
p.set("orientation", "portrait");
p.set("rotation",90);
}
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE)
{
p.set("orientation", "landscape");
p.set("rotation", 90);
}
版本2.1：取决于设备类型，例如，Cannt修复XPeria X10的问题，但它对X8和Mini
有利Camera.Parameters parameters = camera.getParameters();
parameters.set("orientation", "portrait");
camera.setParameters(parameters);
2.2版：不适用于所有设备
camera.setDisplayOrientation(90);
答案 1 :(得分：32)
来自setDisplayOrientation(int)的Javadoc（需要API等级9）：
public static void setCameraDisplayOrientation(Activity activity,
int cameraId, android.hardware.Camera camera) {
android.hardware.Camera.CameraInfo info =
new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(cameraId, info);
int rotation = activity.getWindowManager().getDefaultDisplay()
.getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0: degrees = 0; break;
case Surface.ROTATION_90: degrees = 90; break;
case Surface.ROTATION_180: degrees = 180; break;
case Surface.ROTATION_270: degrees = 270; break;
}
int result;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360; // compensate the mirror
} else { // back-facing
result = (info.orientation - degrees + 360) % 360;
}
camera.setDisplayOrientation(result);
}
答案 2 :(得分：25)
此解决方案适用于所有版本的Android。您可以在Java中使用反射使其适用于所有Android设备：
基本上你应该创建一个反射包装来调用Android 2.2 setDisplayOrientation，而不是调用特定的方法。
方法：
protected void setDisplayOrientation(Camera camera, int angle){
Method downPolymorphic;
try
{
downPolymorphic = camera.getClass().getMethod("setDisplayOrientation", new Class[] { int.class });
if (downPolymorphic != null)
downPolymorphic.invoke(camera, new Object[] { angle });
}
catch (Exception e1)
{
}
}
而不是使用 camera.setDisplayOrientation（x）使用 setDisplayOrientation（camera，x）：
if (Integer.parseInt(Build.VERSION.SDK) >= 8)
setDisplayOrientation(mCamera, 90);
else
{
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT)
{
p.set("orientation", "portrait");
p.set("rotation", 90);
}
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE)
{
p.set("orientation", "landscape");
p.set("rotation", 90);
}
}
答案 3 :(得分：6)
当我使用ZBar在标签中进行扫描时，我遇到了这个问题。 相机方向问题。使用下面的代码，我能够解决问题。 这不是整个代码段，请仅从此处获取帮助。
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
if (isPreviewRunning) {
mCamera.stopPreview();
}
setCameraDisplayOrientation(mCamera);
previewCamera();
}
public void previewCamera() {
try {
// Hard code camera surface rotation 90 degs to match Activity view
// in portrait
mCamera.setPreviewDisplay(mHolder);
mCamera.setPreviewCallback(previewCallback);
mCamera.startPreview();
mCamera.autoFocus(autoFocusCallback);
isPreviewRunning = true;
} catch (Exception e) {
Log.d("DBG", "Error starting camera preview: " + e.getMessage());
}
}
public void setCameraDisplayOrientation(android.hardware.Camera camera) {
Camera.Parameters parameters = camera.getParameters();
android.hardware.Camera.CameraInfo camInfo =
new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(getBackFacingCameraId(), camInfo);
Display display = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int rotation = display.getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0;
break;
case Surface.ROTATION_90:
degrees = 90;
break;
case Surface.ROTATION_180:
degrees = 180;
break;
case Surface.ROTATION_270:
degrees = 270;
break;
}
int result;
if (camInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (camInfo.orientation + degrees) % 360;
result = (360 - result) % 360; // compensate the mirror
} else { // back-facing
result = (camInfo.orientation - degrees + 360) % 360;
}
camera.setDisplayOrientation(result);
}
private int getBackFacingCameraId() {
int cameraId = -1;
// Search for the front facing camera
int numberOfCameras = Camera.getNumberOfCameras();
for (int i = 0; i < numberOfCameras; i++) {
Camera.CameraInfo info = new Camera.CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
cameraId = i;
break;
}
}
return cameraId;
}
答案 4 :(得分：5)
我终于使用谷歌的相机应用修复了这个问题。它通过使用传感器获取手机的方向，然后适当地设置EXIF标签。从相机发出的JPEG不会自动定向。
此外，相机预览仅在横向模式下正常工作。如果您需要将您的活动布局纵向定向，则必须使用方向传感器中的值手动完成。
答案 5 :(得分：4)
这个问题很久以前就已经解决了，但是我把所有部分放在一起遇到了一些困难，所以这是我的最终解决方案，希望这会有助于其他人：
public void startPreview() {
try {
Log.i(TAG, "starting preview: " + started);
// ....
Camera.CameraInfo camInfo = new Camera.CameraInfo();
Camera.getCameraInfo(cameraIndex, camInfo);
int cameraRotationOffset = camInfo.orientation;
// ...
Camera.Parameters parameters = camera.getParameters();
List<Camera.Size> previewSizes = parameters.getSupportedPreviewSizes();
Camera.Size previewSize = null;
float closestRatio = Float.MAX_VALUE;
int targetPreviewWidth = isLandscape() ? getWidth() : getHeight();
int targetPreviewHeight = isLandscape() ? getHeight() : getWidth();
float targetRatio = targetPreviewWidth / (float) targetPreviewHeight;
Log.v(TAG, "target size: " + targetPreviewWidth + " / " + targetPreviewHeight + " ratio:" + targetRatio);
for (Camera.Size candidateSize : previewSizes) {
float whRatio = candidateSize.width / (float) candidateSize.height;
if (previewSize == null || Math.abs(targetRatio - whRatio) < Math.abs(targetRatio - closestRatio)) {
closestRatio = whRatio;
previewSize = candidateSize;
}
}
int rotation = getWindowManager().getDefaultDisplay().getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0;
break; // Natural orientation
case Surface.ROTATION_90:
degrees = 90;
break; // Landscape left
case Surface.ROTATION_180:
degrees = 180;
break;// Upside down
case Surface.ROTATION_270:
degrees = 270;
break;// Landscape right
}
int displayRotation;
if (isFrontFacingCam) {
displayRotation = (cameraRotationOffset + degrees) % 360;
displayRotation = (360 - displayRotation) % 360; // compensate
// the
// mirror
} else { // back-facing
displayRotation = (cameraRotationOffset - degrees + 360) % 360;
}
Log.v(TAG, "rotation cam / phone = displayRotation: " + cameraRotationOffset + " / " + degrees + " = "
+ displayRotation);
this.camera.setDisplayOrientation(displayRotation);
int rotate;
if (isFrontFacingCam) {
rotate = (360 + cameraRotationOffset + degrees) % 360;
} else {
rotate = (360 + cameraRotationOffset - degrees) % 360;
}
Log.v(TAG, "screenshot rotation: " + cameraRotationOffset + " / " + degrees + " = " + rotate);
Log.v(TAG, "preview size: " + previewSize.width + " / " + previewSize.height);
parameters.setPreviewSize(previewSize.width, previewSize.height);
parameters.setRotation(rotate);
camera.setParameters(parameters);
camera.setPreviewDisplay(mHolder);
camera.startPreview();
Log.d(TAG, "preview started");
started = true;
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
答案 6 :(得分：4)
查看此解决方案
public static void setCameraDisplayOrientation(Activity activity,
int cameraId, android.hardware.Camera camera) {
android.hardware.Camera.CameraInfo info =
new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(cameraId, info);
int rotation = activity.getWindowManager().getDefaultDisplay()
.getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0: degrees = 0; break;
case Surface.ROTATION_90: degrees = 90; break;
case Surface.ROTATION_180: degrees = 180; break;
case Surface.ROTATION_270: degrees = 270; break;
}
int result;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360; // compensate the mirror
} else { // back-facing
result = (info.orientation - degrees + 360) % 360;
}
camera.setDisplayOrientation(result);
}