大佬教程收集整理的这篇文章主要介绍了Android自定义照相机详解,大佬教程大佬觉得挺不错的,现在分享给大家,也给大家做个参考。
几乎每个APP都会用的相机功能,下面小编把内容整理分享到编程小技巧平台,供大家参考,感兴趣的朋友一起学习吧!
@H_607_3@启动相机的两种方式
1.直接启动系统相机
<code class="hljs avrasm"> Intent intent = new Intent(); intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE); startActivity(intent);</code>
或者指定返回图片的@L_823_4@mCurrentPhotoFile
<code class="hljs avrasm"> Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); intent.putExtra(MediaStore.EXTRA_OUTPUT,Uri.fromFile(mCurrentPhotoFilE)); startActivityForResult(intent,CAMERA_WITH_DATA);</code>
2.自定义启动相机
今天以第二种为例。效果图如下
创建显示相机画面的布局,Android已经为我们选定好SurfaceView 通过SurfaceView#getHolder()获得链接Camera和SurfaceView的SurfaceHolder Camame.open()打开相机 通过SurfaceHolder链接Camera和SurfaceView
<code class="hljs java">public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.CallBACk,Camera.AutoFocusCallBACk { private static final String TAG = "CameraSurfaceView"; private Context mContext; private SurfaceHolder holder; private Camera mCamera; privatE int mScreenWidth; privatE int mScreenHeight; public CameraSurfaceView(Context context) { this(context,null); } public CameraSurfaceView(Context context,AttributeSet attrs) { this(context,attrs,0); } public CameraSurfaceView(Context context,AttributeSet attrs,int defStyleAttr) { super(context,defStyleAttr); mContext = context; getScreenMetrix(context); initView(); } private void getScreenMetrix(Context context) { WindowManager WM = (WindowManager) context.getSystemservice(Context.WINDOW_serviCE); Displaymetrics outMetrics = new Displaymetrics(); Wm.getDefaultDisplay().getMetrics(outMetrics); mScreenWidth = outMetrics.widthPixels; mScreenHeight = outMetrics.heightPixels; } private void initView() { holder = getHolder();//获得surfaceHolder引用 holder.addCallBACk(this); holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//设置类型 } @Override public void surfaceCreated(SurfaceHolder holder) { Log.i(tag,"surfaceCreated"); if (mCamera == null) { mCamera = Camera.open();//开启相机 try { mCamera.setPreviewDisplay(holder);//摄像头画面显示在Surface上 } catch (IOException E) { e.printStackTrace(); } } } @Override public void surfaceChanged(SurfaceHolder holder,int format,int width,int height) { Log.i(tag,"surfaceChanged"); mCamera.startPreview(); } @Override public void surfaceDestroyed(SurfaceHolder holder) { Log.i(tag,"surfaceDestroyed"); mCamera.stopPreview();//停止预览 mCamera.release();//释放相机资源 mCamera = null; holder = null; } @Override public void onAutoFocus(Boolean success,Camera Camera) { if (success) { Log.i(tag,"onAutoFocus success="+success); } } }</code>
<code class="hljs xml"><uses-permission android:name="android.permission.CAMERA"> <uses-feature android:name="android.hardware.camera.autofocus"></uses-feature></uses-permission></code>
将CameraSurfaceView放在布局文件中,这里建议最外层为FrameLayout,后面会用到。如此,我们便有了一个没有照相功能的相机。初次之外,仔细观察相机显示画面,图片是不是变形严重?那是因为我们还没有为相机设置各种参数。在预览前要设置摄像头的分辨率、预览分辨率和图片分辨率的宽高比保持一致。这样图片才不会变形。这是个比较难以理解的部分,想深刻理解还需读者自己动手去实践。
<code class="hljs java"> private void setCameraParams(Camera camera,"setCameraParams width="+width+" height="+height); Camera.Parameters parameters = mCamera.getParameters(); // 获取摄像头支持的PictureSize列表 List<camera.size> pictureSizeList = parameters.getSupportedPictureSizes(); for (Camera.Size size : pictureSizeList) { Log.i(tag,"pictureSizeList size.width=" + size.width + " size.height=" + size.height); } /**从列表中选取合适的分辨率*/ Camera.Size picSize = getProperSize(pictureSizeList,((float) height / width)); if (null == picSizE) { Log.i(tag,"null == picSize"); picSize = parameters.getPictureSize(); } Log.i(tag,"picSize.width=" + picSize.width + " picSize.height=" + picSize.height); // 根据选出的PictureSize重新设置SurfaceView大小 float w = picSize.width; float h = picSize.height; parameters.setPictureSize(picSize.width,picSize.height); this.setLayoutParams(new FrameLayout.LayoutParams((int) (height*(h/w)),height)); // 获取摄像头支持的PreviewSize列表 List<camera.size> previewSizeList = parameters.getSupportedPreviewSizes(); for (Camera.Size size : previewSizeList) { Log.i(tag,"previewSizeList size.width=" + size.width + " size.height=" + size.height); } Camera.Size preSize = getProperSize(previewSizeList,((float) height) / width); if (null != preSizE) { Log.i(tag,"preSize.width=" + preSize.width + " preSize.height=" + preSize.height); parameters.setPreviewSize(preSize.width,preSize.height); } parameters.setJpegQuality(100); // 设置照片质量 if (parameters.getSupportedFocusModes().contains(android.hardware.Camera.Parameters.FOCUS_MODE_CONTinUOUS_PICTURE)) { parameters.setFocusMode(android.hardware.Camera.Parameters.FOCUS_MODE_CONTinUOUS_PICTURE);// 连续对焦模式 } mCamera.cancelAutoFocus();//自动对焦。 mCamera.setDisplayOrientation(90);// 设置PreviewDisplay的方向,效果就是将捕获的画面旋转多少度显示 mCamera.setParameters(parameters); } /** * 从列表中选取合适的分辨率 * 默认w:h = 4:3 *<p>注意:这里的w对应屏幕的height * h对应屏幕的width</p></camera.size></camera.size></code> */ private Camera.Size getProperSize(List pictureSizeList,float screenRatio) { Log.i(tag,"screenRatio=" + screenRatio); Camera.Size result = null; for (Camera.Size size : pictureSizeList) { float currentRatio = ((float) size.width) / size.height; if (currentRatio - screenRatio == 0) { result = size; break; } } if (null == result) { for (Camera.Size size : pictureSizeList) { float curRatio = ((float) size.width) / size.height; if (curRatio == 4f / 3) {// 默认w:h = 4:3 result = size; break; } } } return result; }
进去的是屏幕宽高,出来的是调整好了的参数。在surfaceChanged方法中执行mCamera.startPreview(); 前调用setCameraParams(mCamera,mScreenWidth,mScreenHeight); 就可以了。最后要@R_674_5313@dManifest.xml里设置activity的方向android:screenOrientation="porTrait"代码里有很多注释,其中也有我自己调试时候的Log,大家可以自己调试下,看看不同参数的效果。昨天调参数搞到一点多,都在折腾这个函数。唉,一把辛酸泪。
身为一个相机,居然不能照相?真是太丢脸了!下面给我们的相机添加上照相的功能。照相核心代码就一句:mCamera.takePicture(null,null,jpeg);
可以看到takePicture方法有三个参数,分别是ShutterCallBACk、PictureCallBACk和PictureCallBACk。这里我们只用了PictureCallBACk
<code class="hljs java"> // 拍照瞬间调用 private Camera.ShutterCallBACk shutter = new Camera.ShutterCallBACk() { @Override public void onShutter() { Log.i(tag,"shutter"); } }; // 获得没有压缩过的图片数据 private Camera.PictureCallBACk raw = new Camera.PictureCallBACk() { @Override public void onPictureTaken(byte[] data,Camera Camera) { Log.i(tag,"raw"); } }; //创建jpeg图片回调数据对象 private Camera.PictureCallBACk jpeg = new Camera.PictureCallBACk() { @Override public void onPictureTaken(byte[] data,Camera Camera) { bufferedoutputstream bos = null; Bitmap bm = null; try { // 获得图片 bm = BitmapFactory.decodeByteArray(data,data.length); if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { Log.i(tag,"Environment.getExternalStorageDirectory()="+Environment.getExternalStorageDirectory()); String filePath = "/sdcard/dyk"+System.currentTimeMillis()+".jpg";//照片保存路径 File file = new File(filePath); if (!file.exists()){ file.createNewFile(); } bos = new bufferedoutputstream(new FiLeoutputStream(filE)); bm.compress(Bitmap.CompressFormat.JPEG,100,bos);//将图片压缩到流中 }else{ Toast.makeText(mContext,"没有检测到内存卡",Toast.LENGTH_SHORT).show(); } } catch (Exception E) { e.printStackTrace(); } finally { try { bos.flush();//输出 bos.close();//关闭 bm.recycle();// 回收bitmap空间 mCamera.stopPreview();// 关闭预览 mCamera.startPreview();// 开启预览 } catch (IOException E) { e.printStackTrace(); } } } };</code>
在jpeg的onPictureTaken里。我们将存储照片信息的byte[] data解析成bitmap,然后转换成JPG格式的图片保存在SD卡中。注意finally中最后两句mCamera.stopPreview();// 关闭预览 mCamera.startPreview();// 开启预览 上文也提到:当调用camera.takePiture方法后,camera关闭了预览,这时需要调用startPreview()来重新开启预览。如果不再次开启预览,则会一直停留在拍摄照片画面。为了方便外部调用拍照。这里我暴露了一个方法供外部拍照。
<code class="hljs cs"> public void takePicture(){ //设置参数,并拍照 setCameraParams(mCamera,mScreenHeight); // 当调用camera.takePiture方法后,camera关闭了预览,这时需要调用startPreview()来重新开启预览 mCamera.takePicture(null,jpeg); }</code>
在布局文件中添加一个Button,点击Button执行takePicture()方法。不要忘了添加写SD卡限权
<code class="hljs xml"><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission></code>
至此,一个具有照相并保存拍摄图片功能的相机就做出来了。But,我们就此满足了吗?要是为了这些简单的功能我也不会写这篇博客。这只是个开始
@H_607_3@真正的开始
昨天看见别的APP在照相的时候,屏幕上居然可以显示像效果图那样的框框啦、辅助点啦、图片bulabulabula~。在网上搜索一番实现方式,再加上一些自己的理解,构成了这篇博客。
上文布局文件一直没有贴,现在贴出来大家先扫一眼,有些控件会在接下来展示
<code class="hljs xml"><!--?xml version="1.0" encoding="utf-8"?--> <framelayout android:layout_height="match_parent" android:layout_width="match_parent" xmlns:android="http://scheR_869_11845@as.android.com/apk/res/android"> <com.dyk.cameratest.view.camerasurfaceview android:id="@+id/cameraSurfaceView" android:layout_height="match_parent" android:layout_width="match_parent"> <com.dyk.cameratest.view.rectoncamera android:layout_height="match_parent" android:layout_width="match_parent"> <relativelayout android:layout_height="match_parent" android:layout_width="match_parent"> </relativelayout></com.dyk.cameratest.view.rectoncamera></com.dyk.cameratest.view.camerasurfaceview></framelayout></code><button android:BACkground="#88427ac7" android:id="@+id/takePic" android:layout_alignparentbottom="true" android:layout_centerhorizontal="true" android:layout_height="50dp" android:layout_marginbottom="20dp" android:layout_width="80dp" android:text="拍照" android:textcolor="#aaa"><code class="hljs xml"> </code></button>
布局文件的最外层是个FrameLayout,我们知道FrameLayout是自带覆盖效果的。由来这个思路接下来就很简单了。编程重要的是思想,思想有了,其余的就剩具体的实现细节。
为了和CameraSurfaceView区分开,再自定义一个RectOnCamera专门用来画边边框框这些东西。这样做还一个好处是方便维护,不至于将所有东西都放在一个View中。
RectOnCamera
<code class="hljs java">package com.dyk.cameratest.view; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Point; import android.graphics.RectF; import android.util.AttributeSet; import android.util.Displaymetrics; import android.util.Log; import android.view.MotionEvent; import android.view.View; import android.view.WindowManager; /** * Created by dyk on 2016/4/7. */ public class RectOnCamera extends View { private static final String TAG = "CameraSurfaceView"; privatE int mScreenWidth; privatE int mScreenHeight; private Paint mPaint; private RectF mRectF; // 圆 private Point centerPoint; privatE int radio; public RectOnCamera(Context context) { this(context,null); } public RectOnCamera(Context context,0); } public RectOnCamera(Context context,defStyleAttr); getScreenMetrix(context); initView(context); } private void getScreenMetrix(Context context) { WindowManager WM = (WindowManager) context.getSystemservice(Context.WINDOW_serviCE); Displaymetrics outMetrics = new Displaymetrics(); Wm.getDefaultDisplay().getMetrics(outMetrics); mScreenWidth = outMetrics.widthPixels; mScreenHeight = outMetrics.heightPixels; } private void initView(Context context) { mPaint = new Paint(); mPaint.setAntiAlias(true);// 抗锯齿 mPaint.setDither(true);// 防抖动 mPaint.setColor(Color.RED); mPaint.setstrokeWidth(5); mPaint.setStyle(Paint.Style.stroke);// 空心 int marginLeft = (int) (mScreenWidth*0.15); int marginTop = (int) (mScreenHeight * 0.25); mRectF = new RectF(marginLeft,marginTop,mScreenWidth - marginLeft,mScreenHeight - marginTop); centerPoint = new Point(mScreenWidth/2,mScreenHeight/2); radio = (int) (mScreenWidth*0.1); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); mPaint.setColor(Color.RED); canvas.drawRect(mRectF,mPaint); mPaint.setColor(Color.WHITE); Log.i(tag,"onDraw"); canvas.drawCircle(centerPoint.x,centerPoint.y,radio,mPaint);// 外圆 canvas.drawCircle(centerPoint.x,radio - 20,mPaint); // 内圆 } } </code>
这里简单的画了一个类似二维码扫描的框框,还有一个类似聚焦的内外圆。那么问题来了,聚焦的内外圆要随着手指滑而改变位置,而且要有聚焦的效果。可又和具有聚焦功能的CameraSurfaceView不是同一个类,不仅如此聚焦内外圆还完全覆盖了CameraSurfaceView。要处理这种问题,需要接口回调。这就是思想下面的细节。现在虽然确定接口回调,但还有一个问题,CameraSurfaceView类和RectOnCamera类中都没有对方的对象或者引用。没错,通过共同持有RectOnCamera和CameraSurfaceView的Activity可以实现此功能。下面是具体的实现方法。
@H_607_3@动起来
首先,想要随着手指的滑动而改变RectOnCamera的位置肯定是要复写onTouchEvent()方法
<code class="hljs cs"> @Override public Boolean onTouchEvent(MotionEvent event) { switch (event.getAction()){ case MotionEvent.ACTION_DOWN: case MotionEvent.ACTION_MOVE: case MotionEvent.ACTION_UP: int x = (int) event.getX(); int y = (int) event.getY(); centerPoint = new Point(x,y); invalidate(); return true; } return true; }</code>
@H_607_3@其次,定义回调接口
<code class="hljs java"> private IAutoFocus mIAutoFocus; /** 聚焦的回调接口 */ public interface IAutoFocus{ void autoFocus(); } public void setIAutoFocus(IAutoFocus mIAutoFocus) { this.mIAutoFocus = mIAutoFocus; }</code>
在onTouchEvent()中return前加入
至此我们的回调接口已经定义好了,此时还需要CameraSurfaceView暴露一个聚焦方法,以便Activity调用
准备工作已经全部完成,下面请看Activity的具体实现:
<code class="hljs java">public class MainActivity extends Activity implements View.onClickListener,RectOnCamera.IAutoFocus{ private CameraSurfaceView mCameraSurfaceView; private RectOnCamera mRectOnCamera; private Button takePicBtn; private Boolean isClicked; @Override protected void onCreate(Bundle savedInstanceStatE) { super.onCreate(savedInstanceStatE); requestWindowFeature(Window.FEATURE_NO_titlE); // 全屏显示 getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(R.layout.activity_main); mCameraSurfaceView = (CameraSurfaceView) findViewById(R.id.cameraSurfaceView); mRectOnCamera = (RectOnCamera) findViewById(R.id.rectOnCamera); takePicBtn= (Button) findViewById(R.id.takePic); mRectOnCamera.setIAutoFocus(this); takePicBtn.setOnClickListener(this); } @Override public void onClick(View v) { switch (v.getId()){ case R.id.takePic: mCameraSurfaceView.takePicture(); break; default: break; } } @Override public void autoFocus() { mCameraSurfaceView.setAutoFocus(); } } </code>
可以看到,MainActivity实现了IAutoFocus接口,并且在复写的IAutoFocus#autoFocus()方法中,调用了CameraSurfaceView暴露出来的方法setAutoFocus()。至此,在RectOnCamera每次的滑动过程中都会改变聚焦内外圆的位置,还会增加聚焦功能。一心二用甚至一心多用岂不是更好。
好了,Android自定义照相机教程到此结束,希望对大家有所帮助!
@H_607_3@编程小技巧推荐阅读:
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