Android：相机预览看起来不太好

我写了一个拍照的相机应用程序（活动），但显示相机实时图片的预览看起来并不好看，它有点高，像这样：

这是我的相机预览的代码：

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback { private SurfaceHolder mHolder ; private Camera mCamera; public CameraPreview(Context context , Camera camera) { super(context) ; mCamera = camera ; mHolder = getHolder(); mHolder.addCallback(this); mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } public void surfaceCreated(SurfaceHolder holder) { try { mCamera.setPreviewDisplay(holder); mCamera.startPreview(); } catch(IOException e) { Log.d(TAG,"Camera Preview Failed!: "+e.getMessage()); } } public void surfaceChanged(SurfaceHolder holder , int m , int n , int w) { } public void surfaceDestroyed(SurfaceHolder holder) { } }        

Answer 1

 public class IQCameraView extends ViewGroup implements SurfaceHolder.Callback { public static final int CAMERA_ERROR = 0; public static final int CAMERA_RESULT = 1; private final String TAG = "Preview"; private SurfaceView mSurfaceView; private SurfaceHolder mHolder; private Size mPreviewSize; private List mSupportedPreviewSizes; private Camera mCamera; private boolean mCameraActive; private IQCameraCallback mCallback; /** * @param mCallback * of type IQCameraCallback * @return of type null setter function for mCallback * @since 10 Oct 2012 */ public void setmCallback(IQCameraCallback mCallback) { this.mCallback = mCallback; } /** * @param context * of type Context * @return of type boolean function which will check the system has a camera * or not * @since 10 Oct 2012 */ public static boolean checkCameraHardware(Context context) { if (context.getPackageManager().hasSystemFeature( PackageManager.FEATURE_CAMERA)) { return true; } else { return false; } } /** * @param context * Constructor function * @since 16 Oct 2012 */ public IQCameraView(Context context) { super(context); mSurfaceView = new SurfaceView(context); addView(mSurfaceView); mHolder = mSurfaceView.getHolder(); mHolder.addCallback(this); mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } /** * @param camera * of type Camera * @return of type null setter function for mCamera * @since 16 Oct 2012 */ public void setCamera(Camera camera) { mCamera = camera; if (mCamera != null) { mSupportedPreviewSizes = mCamera.getParameters() .getSupportedPreviewSizes(); requestLayout(); } } /** * @param of * type null * @return of type null function which will get the current frame from the * camera * @since 16 Oct 2012 */ public void takePicture() { if (null != mCamera && mCameraActive) { mCamera.takePicture(null, null, new IQPhotoHandler(getContext(), this)); } } /** * @param result * of type String * @return of type null function which will be called when the image save is * complete * @since 16 Oct 2012 */ public void onImageCapture(final String result) { if (null != mCallback) { mCallback.onCameraCallback(CAMERA_RESULT, result); } mCamera.startPreview(); } /* * (non-Javadoc) * * @see android.view.View#onMeasure(int, int) * * @since 16 Oct 2012 */ @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { // We purposely disregard child measurements because act as a // Wrapper to a SurfaceView that centers the camera preview instead of // stretching it. final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec); final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec); setMeasuredDimension(width, height); if (mSupportedPreviewSizes != null) { mPreviewSize = getPreviewSize(mSupportedPreviewSizes, width, height); } } /* * (non-Javadoc) * * @see android.view.ViewGroup#onLayout(boolean, int, int, int, int) * * @since 16 Oct 2012 */ @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { if (changed && getChildCount() > 0) { final View child = getChildAt(0); final int width = r - l; final int height = b - t; int previewWidth = width; int previewHeight = height; // Center the child SurfaceView within the parent. if (width * previewHeight > height * previewWidth) { final int scaledChildWidth = previewWidth * height / previewHeight; child.layout((width - scaledChildWidth) / 2, 0, (width + scaledChildWidth) / 2, height); } else { final int scaledChildHeight = previewHeight * width / previewWidth; child.layout(0, (height - scaledChildHeight) / 2, width, (height + scaledChildHeight) / 2); } } } /** * @param of * type null * @return of type null function which will release teh camera * @since 16 Oct 2012 */ public void releaseCamera() { if (null != mCamera && mCameraActive) { mCamera.stopPreview(); mCamera.release(); mCamera = null; } mCameraActive = false; } /* * (non-Javadoc) * * @see * android.view.SurfaceHolder.Callback#surfaceCreated(android.view.SurfaceHolder * ) * * @since 16 Oct 2012 */ public void surfaceCreated(SurfaceHolder holder) { try { if (mCamera != null) { mCamera.setPreviewDisplay(holder); } } catch (IOException e) { Log.e(TAG, "IOException caused by setPreviewDisplay()", e); } } /* * (non-Javadoc) * * @see android.view.SurfaceHolder.Callback#surfaceDestroyed(android.view. * SurfaceHolder) * * @since 16 Oct 2012 */ public void surfaceDestroyed(SurfaceHolder holder) { releaseCamera(); } /* * (non-Javadoc) * * @see * android.view.SurfaceHolder.Callback#surfaceChanged(android.view.SurfaceHolder * , int, int, int) * * @since 16 Oct 2012 */ public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { Camera.Parameters parameters = mCamera.getParameters(); parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height); parameters.setPictureSize(mPreviewSize.width, mPreviewSize.height); parameters.setPictureFormat(PixelFormat.JPEG); mCamera.setDisplayOrientation(90); requestLayout(); try { mCamera.setParameters(parameters); } catch (Exception e) { System.out.print("hih"); } mCamera.startPreview(); mCameraActive = true; } /** * @param sizes * of type List * @param w * of type int * @param h * of type int * @return optionalSize of type Size function which will find the exact size * required for teh camera view * @since 16 Oct 2012 */ private Size getPreviewSize(List sizes, int w, int h) { final double ASPECT_TOLERANCE = 0.1; double targetRatio = (double) w / h; if (sizes == null) return null; Size optimalSize = null; double minDiff = Double.MAX_VALUE; int targetHeight = h; for (Size size : sizes) { 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; } /** * @author rajeshcp * @since 16 Oct 2012 */ public static interface IQCameraCallback { public void onCameraCallback(final int type, final Object param); } } 

试试这个代码用于一个项目，希望这会有所帮助