Android自定义Camera实现拍照功能

2023-09-12 05:25:05 67

本文记录了用自定义Camera实现的简单拍照功能。

Camera类在5.0以后不推荐使用了，取而代之的是android.hardware.camera2包下的类，本文使用Camera。
我们首先自定义一个View去继承SurfaceView:

publicclassCameraSurfaceViewextendsSurfaceViewimplementsSurfaceHolder.Callback,Camera.AutoFocusCallback{
privateSurfaceHoldermHolder;
privateCameramCamera;
privatestaticfinalintORIENTATION=90;
privateintmScreenWidth;
privateintmScreenHeight;
privatebooleanisOpen;

publicCameraSurfaceView(Contextcontext,AttributeSetattrs){
super(context,attrs);
getScreenMatrix(context);
mHolder=getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

privatevoidgetScreenMatrix(Contextcontext){
WindowManagerWM=(WindowManager)context.getSystemService(Context.WINDOW_SERVICE);
DisplayMetricsoutMetrics=newDisplayMetrics();
WM.getDefaultDisplay().getMetrics(outMetrics);
mScreenWidth=outMetrics.widthPixels;
mScreenHeight=outMetrics.heightPixels;
}

publicvoidtakePicture(Camera.ShutterCallbackmShutterCallback,Camera.PictureCallbackrawPictureCallback,Camera.PictureCallbackjpegPictureCallback){
if(mCamera!=null)
mCamera.takePicture(mShutterCallback,rawPictureCallback,jpegPictureCallback);
}

publicvoidstartPreview(){
mCamera.startPreview();
}

@Override
publicvoidsurfaceCreated(SurfaceHolderholder){
if(!checkCameraHardware(getContext()))
return;
if(mCamera==null){
isOpen=safeCameraOpen(Camera.CameraInfo.CAMERA_FACING_BACK);
}
if(!isOpen){
return;
}
mCamera.setDisplayOrientation(ORIENTATION);
try{
mCamera.setPreviewDisplay(holder);

}catch(IOExceptione){
e.printStackTrace();
}
}

@Override
publicvoidsurfaceChanged(SurfaceHolderholder,intformat,intwidth,intheight){
if(mCamera!=null){
setCameraParams(mScreenWidth,mScreenHeight);
mCamera.startPreview();
}
}

@Override
publicvoidsurfaceDestroyed(SurfaceHolderholder){
releaseCameraAndPreview();
}

privatebooleansafeCameraOpen(intid){
booleanqOpened=false;
try{
releaseCameraAndPreview();
mCamera=Camera.open(id);
qOpened=(mCamera!=null);
}catch(Exceptione){
e.printStackTrace();
}

returnqOpened;
}

privatevoidreleaseCameraAndPreview(){
if(mCamera!=null){
mCamera.stopPreview();
mCamera.release();
mCamera=null;
}
}

privatebooleancheckCameraHardware(Contextcontext){
if(context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
returntrue;
}else{
returnfalse;
}
}


@Override
publicvoidonAutoFocus(booleansuccess,Cameracamera){

}

privatevoidsetCameraParams(intwidth,intheight){
Camera.Parametersparameters=mCamera.getParameters();
//获取摄像头支持的PictureSize列表
ListpictureSizeList=parameters.getSupportedPictureSizes();
/**从列表中选取合适的分辨率*/
Camera.SizepicSize=getProperSize(pictureSizeList,((float)height/width));
if(null==picSize){
picSize=parameters.getPictureSize();
}
//根据选出的PictureSize重新设置SurfaceView大小
floatw=picSize.width;
floath=picSize.height;
parameters.setPictureSize(picSize.width,picSize.height);
this.setLayoutParams(newRelativeLayout.LayoutParams((int)(height*(h/w)),height));
//获取摄像头支持的PreviewSize列表
ListpreviewSizeList=parameters.getSupportedPreviewSizes();
Camera.SizepreSize=getProperSize(previewSizeList,((float)height)/width);
if(null!=preSize){
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.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);

}

/**
*选取合适的分辨率
*/
privateCamera.SizegetProperSize(ListpictureSizeList,floatscreenRatio){
Camera.Sizeresult=null;
for(Camera.Sizesize:pictureSizeList){
floatcurrentRatio=((float)size.width)/size.height;
if(currentRatio-screenRatio==0){
result=size;
break;
}
}

if(null==result){
for(Camera.Sizesize:pictureSizeList){
floatcurRatio=((float)size.width)/size.height;
if(curRatio==4f/3){//默认w:h=4:3
result=size;
break;
}
}
}

returnresult;
}
}

代码没什么难度，在View创建的时候完成Camera的初始化，然后对Camera进行参数的设置（图片尺寸，质量之类的），最后别忘了在View销毁的时候对资源进行释放。

控件定义完了之后我们就要去使用它，在布局文件中添加就OK：

然后在Activity中去完成拍照功能：

publicclassCameraActivityextendsAppCompatActivity{
privatebooleanisClick=true;
privatestaticfinalStringPATH_IMAGES=Environment.getExternalStorageDirectory().getAbsolutePath()+File.separator+"easy_check";
privateCameraSurfaceViewmCameraSurfaceView;
//拍照快门的回调
privateCamera.ShutterCallbackmShutterCallback=newCamera.ShutterCallback(){
@Override
publicvoidonShutter(){

}
};
//拍照完成之后返回原始数据的回调
privateCamera.PictureCallbackrawPictureCallback=newCamera.PictureCallback(){
@Override
publicvoidonPictureTaken(byte[]data,Cameracamera){

}
};
//拍照完成之后返回压缩数据的回调
privateCamera.PictureCallbackjpegPictureCallback=newCamera.PictureCallback(){
@Override
publicvoidonPictureTaken(byte[]data,Cameracamera){
mCameraSurfaceView.startPreview();
saveFile(data);
Toast.makeText(CameraActivity.this,"拍照成功",Toast.LENGTH_SHORT).show();
isClick=true;

}
};

@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ImageViewimg_take_photo=(ImageView)findViewById(R.id.img_take_photo);
mCameraSurfaceView=(CameraSurfaceView)findViewById(R.id.sv_camera);
img_take_photo.setOnClickListener(newView.OnClickListener(){
@Override
publicvoidonClick(Viewv){
takePhoto();
}
});
}

publicvoidtakePhoto(){
if(isClick){
isClick=false;
mCameraSurfaceView.takePicture(mShutterCallback,rawPictureCallback,jpegPictureCallback);
}
}
//保存图片到硬盘
publicvoidsaveFile(byte[]data){
StringfileName=UUID.randomUUID().toString()+".jpg";
FileOutputStreamoutputStream=null;
try{
Filefile=newFile(PATH_IMAGES);
if(!file.exists()){
file.mkdirs();
}
outputStream=newFileOutputStream(PATH_IMAGES+File.separator+fileName);
BufferedOutputStreambufferedOutputStream=newBufferedOutputStream(outputStream);
bufferedOutputStream.write(data,0,data.length);
}catch(Exceptione){
e.printStackTrace();
}finally{
try{
outputStream.close();
}catch(IOExceptione){
e.printStackTrace();
}
}
}
}

最后记得添加拍照跟磁盘操作权限：

到这一个非常简单的拍照Demo就完成了，只能当做Demo使用，离开发正式使用还有一段的距离，再次特地记录一下。

下载：源码

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。

Android自定义Camera实现拍照功能

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