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本文出自：马云飞的博客
最近要整理的东西比较多，比较乱，一个一个来把，自定义layout实现recyclerview的下拉刷新和上拉加载还是没有什么思路。刚好前几天上司让我做几个关于camera的界面，我就先介绍下camera把，android4.0后更新了一个控件，textureview，个人感觉而言，它比surfaceview好用很多，不多说，上代码：
textureview.addOnLayoutChangeListener(this);matrix = new Matrix();textureview.setSurfaceTextureListener(new TextureView.SurfaceTextureListener() {public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int i, int i1) {camera = Camera.open(0);RectF previewRect = new RectF(0, 0, mWidth, mHeight);double aspect = (double) mPreviewWidth / mPreviewHeight;if (getResources().getConfiguration().orientation== Configuration.ORIENTATION_PORTRAIT) {aspect = 1 / aspect;}if (mWidth < (mHeight * aspect)) {mDisplayWidth = mWidth;mDisplayHeight = (int) (mHeight * aspect + .5);} else {mDisplayWidth = (int) (mWidth / aspect + .5);mDisplayHeight = mHeight;}RectF surfaceDimensions = new RectF(0, 0, mDisplayWidth, mDisplayHeight);matrix.setRectToRect(previewRect, surfaceDimensions, Matrix.ScaleToFit.FILL);//textureview.setTransform(matrix);param = camera.getParameters();int displayRotation = 0;WindowManager windowManager = (WindowManager) PhotoActivity.this.getSystemService(Context.WINDOW_SERVICE);int rotation = windowManager.getDefaultDisplay().getRotation();switch (rotation) {case Surface.ROTATION_0:displayRotation = 0;break;case Surface.ROTATION_90:displayRotation = 90;break;case Surface.ROTATION_180:displayRotation = 180;break;case Surface.ROTATION_270:displayRotation = 270;break;}Camera.CameraInfo info = new Camera.CameraInfo();Camera.getCameraInfo(0, info);if (info.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {orientation = (info.orientation - displayRotation + 360) % 360;} else {orientation = (info.orientation + displayRotation) % 360;orientation = (360 - orientation) % 360;}param.setPreviewSize(mPreviewWidth, mPreviewHeight);camera.setParameters(param);camera.setDisplayOrientation(orientation);try {camera.setPreviewTexture(surfaceTexture);} catch (IOException e) {}camera.startPreview();//textureview.setAlpha(1.0f);//textureview.setRotation(90.0f);}public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int i, int i1) {}public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {//camera.setPreviewCallback(null);//camera.stopPreview();//camera.release();surfaceTexture.release();camera = null;return true;}public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {}});
上面代码主要是讲camera和textureview绑定起来，以及textureview的呈现区域不变形。
priview的宽高我设置的是640*480，正常比例是0.75（480*640）.因为摄像头是要通过旋转90°来显示，所以我把他的宽高640*480.
下面代码主要是实现，主副摄像头的切换，以及开关闪光灯。
@OnClick({R.id.back, R.id.camera_head, R.id.light, R.id.shot})public void onClick(View view) {switch (view.getId()) {case R.id.back:finish();break;case R.id.camera_head:if (!isFront) {camera.stopPreview();camera.release();camera = Camera.open(1);param = camera.getParameters();param.setPreviewSize(mPreviewWidth, mPreviewHeight);camera.setParameters(param);camera.setDisplayOrientation(orientation);try {camera.setPreviewTexture(textureview.getSurfaceTexture());} catch (IOException e) {e.printStackTrace();}camera.startPreview();isFront = true;} else {camera.stopPreview();camera.release();camera = Camera.open(0);param = camera.getParameters();param.setPreviewSize(mPreviewWidth, mPreviewHeight);camera.setParameters(param);camera.setDisplayOrientation(orientation);try {camera.setPreviewTexture(textureview.getSurfaceTexture());} catch (IOException e) {e.printStackTrace();}camera.startPreview();isFront = false;}break;case R.id.light:if (!isLight) {parameter = camera.getParameters();parameter.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);camera.setParameters(parameter);light.setImageResource(R.drawable.open_light);isLight = true;} else {parameter.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);camera.setParameters(parameter);light.setImageResource(R.drawable.close_light);isLight = false;}break;case R.id.shot:camera.takePicture(null, null, this);break;}
camera.takepicture（），就是进行拍照了，这个很简单，把他保存在sd的路径就可以了。代码如下：
// data是字节数据，将其解析成位图Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);Matrix matrix = new Matrix();// 使图片旋转90°matrix.preRotate(90);bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),bitmap.getHeight(), matrix, true);// 保存图片到sdcard// 获取SD卡的路径File file = new File(Environment.getExternalStorageDirectory(),System.currentTimeMillis() + ".jpg");FileOutputStream outputStream = new FileOutputStream(file);// 压缩图片，不压缩是100，表示压缩率为press(pressFormat.JPEG, 100, outputStream);outputStream.close();// 停止预览camera.stopPreview();camera.release();camera = Camera.open(0);param = camera.getParameters();param.setPreviewSize(mPreviewWidth, mPreviewHeight);camera.setParameters(param);camera.setDisplayOrientation(orientation);try {camera.setPreviewTexture(textureview.getSurfaceTexture());} catch (IOException e) {e.printStackTrace();}camera.startPreview();// 处理完数据之后可以预览Log.e("pig", file.getPath());} catch (Exception e) {e.printStackTrace();}
当然，最后还有textureview的layout变化的宽高改变，以及一些权限，代码如下：
public void onLayoutChange(View v, int left, int top, int right,int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {mWidth = right - left;mHeight = bottom - top;}
<uses-permission android:name="android.permission.FLASHLIGHT" /><uses-permission android:name="android.permission.CAMERA" /><uses-permission android:name="android.permission.RECORD_AUDIO" /><uses-permission android:name="android.permission.RECORD_VIDEO"/><uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /><uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" /><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
这样，一个camera拍照功能就解决了。比较麻烦就是textureview使camera变形的问题。
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