【移动应用开发技术】怎么在Android中通过自定义Camera实现拍照功能

【移动应用开发技术】怎么在Android中通过自定义Camera实现拍照功能

这篇文章给大家介绍怎么在Android中通过自定义Camera实现拍照功能，内容非常详细，感兴趣的小伙伴们可以参考借鉴，希望对大家能有所帮助。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:public

class

CameraSurfaceView

extends

SurfaceView

implements

SurfaceHolder.Callback,

Camera.AutoFocusCallback

{

private

SurfaceHolder

mHolder;

private

Camera

mCamera;

private

static

final

int

ORIENTATION

=

90;

private

int

mScreenWidth;

private

int

mScreenHeight;

private

boolean

isOpen;

public

CameraSurfaceView(Context

context,

AttributeSet

attrs)

{

super(context,

attrs);

getScreenMatrix(context);

mHolder

=

getHolder();

mHolder.addCallback(this);

mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

}

private

void

getScreenMatrix(Context

context)

{

WindowManager

WM

=

(WindowManager)

context.getSystemService(Context.WINDOW_SERVICE);

DisplayMetrics

outMetrics

=

new

DisplayMetrics();

WM.getDefaultDisplay().getMetrics(outMetrics);

mScreenWidth

=

outMetrics.widthPixels;

mScreenHeight

=

outMetrics.heightPixels;

}

public

void

takePicture(Camera.ShutterCallback

mShutterCallback,

Camera.PictureCallback

rawPictureCallback,

Camera.PictureCallback

jpegPictureCallback)

{

if

(mCamera

!=

null)

mCamera.takePicture(mShutterCallback,

rawPictureCallback,

jpegPictureCallback);

}

public

void

startPreview()

{

mCamera.startPreview();

}

@Override

public

void

surfaceCreated(SurfaceHolder

holder)

{

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

(IOException

e)

{

e.printStackTrace();

}

}

@Override

public

void

surfaceChanged(SurfaceHolder

holder,

int

format,

int

width,

int

height)

{

if

(mCamera

!=

null)

{

setCameraParams(mScreenWidth,

mScreenHeight);

mCamera.startPreview();

}

}

@Override

public

void

surfaceDestroyed(SurfaceHolder

holder)

{

releaseCameraAndPreview();

}

private

boolean

safeCameraOpen(int

id)

{

boolean

qOpened

=

false;

try

{

releaseCameraAndPreview();

mCamera

=

Camera.open(id);

qOpened

=

(mCamera

!=

null);

}

catch

(Exception

e)

{

e.printStackTrace();

}

return

qOpened;

}

private

void

releaseCameraAndPreview()

{

if

(mCamera

!=

null)

{

mCamera.stopPreview();

mCamera.release();

mCamera

=

null;

}

}

private

boolean

checkCameraHardware(Context

context)

{

if

(context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA))

{

return

true;

}

else

{

return

false;

}

}

@Override

public

void

onAutoFocus(boolean

success,

Camera

camera)

{

}

private

void

setCameraParams(int

width,

int

height)

{

Camera.Parameters

parameters

=

mCamera.getParameters();

//

获取摄像头支持的PictureSize列表

List<Camera.Size>

pictureSizeList

=

parameters.getSupportedPictureSizes();

/**从列表中选取合适的分辨率*/

Camera.Size

picSize

=

getProperSize(pictureSizeList,

((float)

height

/

width));

if

(null

==

picSize)

{

picSize

=

parameters.getPictureSize();

}

//

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

RelativeLayout.LayoutParams((int)

(height

*

(h

/

w)),

height));

//

获取摄像头支持的PreviewSize列表

List<Camera.Size>

previewSizeList

=

parameters.getSupportedPreviewSizes();

Camera.Size

preSize

=

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

*/

private

Camera.Size

getProperSize(List<Camera.Size>

pictureSizeList,

float

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;

}

}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：<?xml

version="1.0"

encoding="utf-8"?>

<RelativeLayout

xmlns:android="/apk/res/android"

android:id="@+id/activity_main"

android:layout_width="match_parent"

android:layout_height="match_parent"

>

<com.padoon.cameratest.CameraSurfaceView

android:id="@+id/sv_camera"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:layout_weight="4"/>

<ImageView

android:id="@+id/img_take_photo"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentBottom="true"

android:layout_alignParentRight="true"

android:layout_gravity="bottom"

android:layout_marginBottom="10dp"

android:layout_marginRight="10dp"

android:src="@mipmap/icon_camera"/>

</RelativeLayout>然后在Activity中去完成拍照功能：public

class

CameraActivity

extends

AppCompatActivity

{

private

boolean

isClick

=

true;

private

static

final

String

PATH_IMAGES

=

Environment.getExternalStorageDirectory().getAbsolutePath()

+

File.separator

+

"easy_check";

private

CameraSurfaceView

mCameraSurfaceView;

//拍照快门的回调

private

Camera.ShutterCallback

mShutterCallback

=

new

Camera.ShutterCallback()

{

@Override

public

void

onShutter()

{

}

};

//拍照完成之后返回原始数据的回调

private

Camera.PictureCallback

rawPictureCallback

=

new

Camera.PictureCallback()

{

@Override

public

void

onPictureTaken(byte[]

data,

Camera

camera)

{

}

};

//拍照完成之后返回压缩数据的回调

private

Camera.PictureCallback

jpegPictureCallback

=

new

Camera.PictureCallback()

{

@Override

public

void

onPictureTaken(byte[]

data,

Camera

camera)

{

mCameraSurfaceView.startPreview();

saveFile(data);

Toast.makeText(CameraActivity.this,

"拍照成功",

Toast.LENGTH_SHORT).show();

isClick

=

true;

}

};

@Override

protected

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

ImageView

img_take_photo

=

(ImageView)

findViewById(R.id.img_take_photo);

mCameraSurfaceView

=

(CameraSurfaceView)

findViewById(R.id.sv_camera);

img_take_photo.setOnClickListener(new

View.OnClickListener()

{

@Override

public

void

onClick(View

v)

{

takePhoto();

}

});

}

public

void

takePhoto()

{

if

(isClick)

{

isClick

=

false;

mCameraSurfaceView.takePicture(mShutterCallback,

rawPictureCallback,

jpegPictureCallback);

}

}

//保存图片到硬盘

public

void

saveFile(byte[]

data)

{

String

fileName

=

UUID.randomUUID().toString()

+

".jpg";

FileOutputStream

outputStream

=

null;

tr