相机预览显示的是扭曲的图像，在纵向模式下会拉长，在横向时会变平。我已经用百万种技术调整了预览大小。然后我在某处阅读它必须是调整SurfaceView的大小。但到目前为止，我还没有找到合适的东西。
这是我的activity.java文件：
public class CameraActivity extends Activity {
private Camera mCamera;
private CameraPreview mPreview;
private FrameLayout preview;
private static final String TAG = "CameraActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera);
if (checkCameraHardware(getBaseContext())){
// Create an instance of Camera
mCamera = getCameraInstance();
// Create our Preview view and set it as the content of our activity.
mPreview = new CameraPreview(this, mCamera, CameraActivity.this);
preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(mPreview);
}
}
/** Check if this device has a camera */
private boolean checkCameraHardware(Context context) {
if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
Log.d(TAG, "Camera Available");
return true;
} else {
Log.d(TAG, "No Camera Found");
return false;
}
}
/** A safe way to get an instance of the Camera object. */
public Camera getCameraInstance(){
Camera c = null;
try {
int i = Camera.getNumberOfCameras();
releaseCamera(); //in case camera is being accessed by any other app.
Log.d(TAG, "Number of Cameras "+i +"\n");
c = Camera.open(); // attempt to get a Camera instance
Log.d(TAG, "Camera Opened");
}
catch (Exception e){
Log.d(TAG, "Camera Can't Be Accessed");
}
return c; // returns null if camera is unavailable
}
@Override
protected void onPause() {
super.onPause();
releaseCamera(); // release the camera immediately on pause event
}
private void releaseCamera(){
if (mCamera != null){
//mCamera.setPreviewCallback(null);
mPreview.getHolder().removeCallback(mPreview);
mCamera.release(); // release the camera for other applications
}
}
这是我的相机预览课程：
@SuppressLint("ViewConstructor")
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = "CameraPreview";
private SurfaceHolder mHolder;
private Camera mCamera;
private Size mPreviewSize;
@SuppressWarnings("deprecation")
public CameraPreview(Context context, Camera camera, Activity activity) {
super(context);
mCamera = camera;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
if (mHolder.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try{
mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
Camera.Parameters parameters = mCamera.getParameters();
List<Size> localSizes = mCamera.getParameters().getSupportedPreviewSizes();
mPreviewSize = localSizes.get(0);
Log.d(TAG, "Width " + mPreviewSize.width);
Log.d(TAG, "Height " + mPreviewSize.height);
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height );
requestLayout();
mCamera.setParameters(parameters);
//start preview with new settings
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e){
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
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 = 0; break;
case Surface.ROTATION_270: degrees = -90; 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);
}
}
这是我的activity.xml：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:baselineAligned="false"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".CameraActivity" >
<FrameLayout
android:id="@+id/camera_preview"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight = "1"
/>
</LinearLayout>
答案 0 :(得分：1)
您的SurfaceView（或TextureView）必须与预览图片具有相同的宽高比，否则您将获得所描述的失真。
FWIW，您可能会发现使用my CWAC-Camera library很有用，{{3}}提供CameraFragment可以为您处理大量此类低级内容。不过，它仍在进行中。
答案 1 :(得分：1)
您可以找到相机预览宽度＆amp;在onCreate中创建相机实例时的高度。然后，选择layout_width和layout_height，使它们适合预览 FrameLayout并保留相机的纵横比。您可以使用FrameLayout.addView(View, LayoutParams)。
答案 2 :(得分：0)
不确定是否有人仍然会阅读此内容，但我遇到了同样的问题并this answer修复了此问题。 我在这里复制代码以防万一（我也编辑它以匹配这个例子）：
mCamera.Parameters parameters1 = mCamera.getParameters();
parameters1.setPreviewSize(getWidth(), getHeight());
mCamera.setParameters(parameters1);
在此之前添加以下行：
mCamera.startPreview();