【移動應用開發(fā)技術】android中怎么通過自定義Camera實現(xiàn)拍照

android中怎么通過自定義Camera實現(xiàn)拍照，很多新手對此不是很清楚，為了幫助大家解決這個難題，下面在下將為大家詳細講解，有這方面需求的人可以來學習下，希望你能有所收獲。1、打開相機a.預覽拍攝圖片，需用到SurfaceView，并且實現(xiàn)其回調函數(shù)implementsSurfaceHolder.Callback；activity_camera.xml<?xml

version="1.0"

encoding="utf-8"?>

<LinearLayout

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

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

>

<SurfaceView

android:id="@+id/sv"

android:layout_width="match_parent"

android:layout_height="0dp"

android:layout_weight="1"

/>

<Button

android:id="@+id/btn_camera"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="拍照"

/>

</LinearLayout>2、獲取相機并開啟預覽/**

*

獲取系統(tǒng)相機

*

*

@return

*/

private

Camera

getcCamera()

{

Camera

camera

=

null;

try

{

camera

=

Camera.open();

}

catch

(Exception

e)

{

camera

=

null;

}

return

camera;

}/**

*

顯示相機預覽圖片

*

*

@return

*/

private

void

showCameraView(Camera

camera,SurfaceHolder

holder)

{

try

{

camera.setPreviewDisplay(holder);

camera.setDisplayOrientation(90);

camera.startPreview();

}catch

(Exception

e){

e.printStackTrace();

};

}/**

**

實現(xiàn)界面回調處理

*/

@Override

public

void

surfaceCreated(SurfaceHolder

holder)

{

showCameraView(mCamera,

holder);

}

@Override

public

void

surfaceChanged(SurfaceHolder

holder,

int

format,

int

width,

int

height)

{

mCamera.stopPreview();

showCameraView(mCamera,

holder);

}

@Override

public

void

surfaceDestroyed(SurfaceHolder

holder)

{

clearCamera();

}

}3、相機主頁面處理public

class

CameraActivity

extends

AppCompatActivity

implements

SurfaceHolder.Callback{

private

SurfaceView

sv;

private

Camera

mCamera;

private

SurfaceHolder

holder;

@Override

protected

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_camera);

sv

=

(SurfaceView)findViewById(R.id.sv);

holder

=

sv.getHolder();

holder.addCallback(this);

findViewById(R.id.btn_camera).setOnClickListener(new

View.OnClickListener()

{

@Override

public

void

onClick(View

v)

{

//

獲取當前相機參數(shù)

Camera.Parameters

parameters

=

mCamera.getParameters();

//

設置相片格式

parameters.setPictureFormat(ImageFormat.JPEG);

//

設置預覽大小

parameters.setPreviewSize(800,

480);

//

設置對焦方式，這里設置自動對焦

parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);

mCamera.autoFocus(new

Camera.AutoFocusCallback()

{

@Override

public

void

onAutoFocus(boolean

success,

Camera

camera)

{

//

判斷是否對焦成功

if

(success)

{

//

拍照

第三個參數(shù)為拍照回調

mCamera.takePicture(null,

null,

new

Camera.PictureCallback()

{

@Override

public

void

onPictureTaken(byte[]

data,

Camera

camera)

{

//

data為完整數(shù)據(jù)

File

file

=

new

File("/sdcard/photo.png");

//

使用流進行讀寫

try

{

FileOutputStream

fos

=

new

FileOutputStream(file);

try

{

fos.write(data);

//

關閉流

fos.close();

//

查看圖片

Intent

intent

=

new

Intent();

//

傳遞路徑

intent.putExtra("path",

file.getAbsolutePath());

setResult(0,intent);

finish();

}

catch

(IOException

e)

{

//

TODO

Auto-generated

catch

block

e.printStackTrace();

}

}

catch

(FileNotFoundException

e)

{

//

TODO

Auto-generated

catch

block

e.printStackTrace();

}

}

});

}

}

});

}

});

}

@Override

protected

void

onResume()

{

super.onResume();

if

(mCamera

==

null)

{

mCamera

=

getCamera();

if

(holder

!=

null)

{

showCameraView(mCamera,

holder);

}

}

}

@Override

protected

void

onPause()

{

//

TODO

Auto-generated

method

stub

super.onPause();

//

activity暫停時我們釋放相機內存

clearCamera();

}

@Override

protected

void

onDestroy()

{

super.onDestroy();

}

/**

*

釋放相機的內存

*/

private

void

clearCamera()

{

//

釋放hold資源

if

(mCamera

!=

null)

{

//

停止預覽

mCamera.stopPreview();

mCamera.setPreviewCallback(null);

//

釋放相機資源

mCamera.release();

mCamera

=

null;

}

}4、啟動activity（設置拍照完圖片路徑返回顯示圖片處理，一定要對圖片進行采樣率操作（很可能拍照的圖片太多而無法顯示，又不報任何異常））public

class

MainActivity

extends

AppCompatActivity

{

private

ImageView

cameraIv;

@Override

protected

void

onActivityResult(int

requestCode,

int

resultCode,

Intent

data)

{

if(resultCode

==

0

&&

requestCode

==

100)

{

String

path

=

data.getStringExtra("path");

BitmapFactory.Options

options

=

new

BitmapFactory.Options();

options.inJustDecodeBounds

=

true;

BitmapFactory.decodeFile(path,

options);

ImageSize

imageSize

=

getImageViewSize(cameraIv);

options.inSampleSize

=

caculateInSampleSize(options,

imageSize.width,

imageSize.height);

//

使用獲得到的InSampleSize再次解析圖片

options.inJustDecodeBounds

=

false;

Bitmap

bitmap

=

BitmapFactory.decodeFile(path,

options);

cameraIv.setImageBitmap(bitmap);

}

super.onActivityResult(requestCode,

resultCode,

data);

}

@Override

protected

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

Button

openButton

=

(Button)

findViewById(R.id.button);

cameraIv

=

(ImageView)

findViewById(R.id.imageView);

openButton.setOnClickListener(new

View.OnClickListener()

{

@Override

public

void

onClick(View

v)

{

Intent

intent

=

new

Intent(MainActivity.this,CameraActivity.class);

startActivityForResult(intent,100);

}

});

}

/*

根據(jù)需求的寬和高以及圖片實際的寬和高計算SampleSize

*

*

@param

options

*

@param

width

*

@param

height

*

@return

*/

public

static

int

caculateInSampleSize(BitmapFactory.Options

options,

int

reqWidth,

int

reqHeight)

{

int

width

=

options.outWidth;

int

height

=

options.outHeight;

int

inSampleSize

=

1;

if

(width

>

reqWidth

||

height

>

reqHeight)

{

int

widthRadio

=

Math.round(width

*

1.0f

/

reqWidth);

int

heightRadio

=

Math.round(height

*

1.0f

/

reqHeight);

inSampleSize

=

Math.max(widthRadio,

heightRadio);

}

return

inSampleSize;

}

public

static

ImageSize

getImageViewSize(ImageView

imageView)

{

ImageSize

imageSize

=

new

ImageSize();

DisplayMetrics

displayMetrics