【移动应用开发技术】android如何实现简单拍照功能

【移动应用开发技术】android如何实现简单拍照功能

这篇文章主要介绍android如何实现简单拍照功能，文中介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们一定要看完！拍照可以调用系统的相机进行拍照，拍完保存到相应的SD卡目录。最近要用到拍照这个功能，首先试了下调用相机拍照，保存到相应目录，然后用imageview显示的时候感觉，很模糊。可能是图片被压缩的太狠了。所以自己使用Camera写了一个拍照的功能，拍出来的还挺清晰的，不过文件有点大一张图片差不多1.7M。如果想拍高清图可以使用下面的代码。代码很简单，我就不做过多解释了。package

com.example.testsimple;

import

java.io.File;

import

java.io.FileOutputStream;

import

java.io.IOException;

import

java.util.Date;

import

android.os.AsyncTask;

import

android.os.Bundle;

import

android.os.Environment;

import

android.app.Activity;

import

android.content.Intent;

import

android.graphics.Bitmap;

import

android.graphics.BitmapFactory;

import

android.graphics.PixelFormat;

import

android.hardware.Camera;

import

android.text.format.DateFormat;

import

android.util.Log;

import

android.view.KeyEvent;

import

android.view.Menu;

import

android.view.SurfaceHolder;

import

android.view.SurfaceView;

import

android.view.View;

import

android.view.View.OnClickListener;

import

android.widget.Button;

import

android.widget.ImageView;

public

class

MainActivity

extends

Activity

{

private

SurfaceView

surfaceView;

private

SurfaceHolder

surfaceHolder;

private

Camera

camera;

private

File

picture;

private

Button

btnSave;

private

final

static

String

TAG

=

"CameraActivity";

private

ImageView

open_picIcon;

@Override

public

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

/*

Intent

intent=new

Intent(MainActivity.this,MyCameraActivity.class);

startActivity(intent);

finish();*/

setupViews();

}

private

void

setupViews(){

surfaceView

=

(SurfaceView)

findViewById(R.id.camera_preview);

//

Camera

interface

to

instantiate

components

surfaceHolder

=

surfaceView.getHolder();

//

Camera

interface

to

instantiate

components

surfaceHolder.addCallback(surfaceCallback);

//

Add

a

callback

for

the

SurfaceHolder

surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

btnSave

=

(Button)

findViewById(R.id.save_pic);

open_picIcon=(ImageView)

findViewById(R.id.open_picIcon);

btnSave.setOnClickListener(new

OnClickListener()

{

@Override

public

void

onClick(View

v)

{

surfaceView.setVisibility(View.VISIBLE);

open_picIcon.setVisibility(View.GONE);

takePic();

}

});

}

@Override

public

boolean

onKeyDown(int

keyCode,

KeyEvent

event)

{

if

(keyCode

==

KeyEvent.KEYCODE_CAMERA

||

keyCode

==

KeyEvent.KEYCODE_SEARCH)

{

takePic();

return

true;

}

return

super.onKeyDown(keyCode,

event);

}

private

void

takePic()

{

camera.stopPreview();//

stop

the

preview

camera.takePicture(null,

null,

pictureCallback);

//

picture

}

//

Photo

call

back

Camera.PictureCallback

pictureCallback

=

new

Camera.PictureCallback()

{

//@Override

public

void

onPictureTaken(byte[]

data,

Camera

camera)

{

new

SavePictureTask().execute(data);

camera.startPreview();

}

};

//

save

pic

class

SavePictureTask

extends

AsyncTask<byte[],

String,

String>

{

@Override

protected

String

doInBackground(byte[]...

params)

{

String

fname

=

DateFormat.format("yyyyMMddhhmmss",

new

Date()).toString()+".jpg";

Log.i(TAG,

"fname="+fname+";dir="+Environment.getExternalStorageDirectory());

//picture

=

new

File(Environment.getExternalStorageDirectory(),fname);//

create

file

picture

=

new

File(Environment.getExternalStorageDirectory()+"/images/"+fname);

File

file=

picture.getParentFile();

if(!file.exists())

file.mkdir();

try

{

FileOutputStream

fos

=

new

FileOutputStream(picture.getPath());

//

Get

file

output

stream

fos.write(params[0]);

//

Written

to

the

file

fos.close();

}

catch

(Exception

e)

{

e.printStackTrace();

}

return

null;

}

@Override

protected

void

onPostExecute(String

result)

{

//

TODO

Auto-generated

method

stub

super.onPostExecute(result);

Bitmap

bitmap=getDiskBitmap(picture.getPath());

surfaceView.setVisibility(View.GONE);

open_picIcon.setVisibility(View.VISIBLE);

open_picIcon.setImageBitmap(bitmap);

}

}

private

Bitmap

getDiskBitmap(String

pathString)

{

Bitmap

bitmap

=

null;

try

{

File

file

=

new

File(pathString);

if(file.exists())

{

bitmap

=

BitmapFactory.decodeFile(pathString);

}

}

catch

(Exception

e)

{

//

TODO:

handle

exception

}

return

bitmap;

}

//

SurfaceHodler

Callback

handle

to

open

the

camera,

off

camera

and

photo

size

changes

SurfaceHolder.Callback

surfaceCallback

=

new

SurfaceHolder.Callback()

{

public

void

surfaceCreated(SurfaceHolder

holder)

{

Log.i(TAG,

"surfaceCallback====");

camera

=

Camera.open();

//

Turn

on

the

camera

try

{

camera.setPreviewDisplay(holder);

//

Set

Preview

}

catch

(IOException

e)

{

camera.release();//

release

camera

camera

=

null;

}

}

public

void

surfaceChanged(SurfaceHolder

holder,

int

format,

int

width,

int

height)

{

Log.i(TAG,"====surfaceChanged");

Camera.Parameters

parameters

=

camera.getParameters();

//

Camera

parameters

to

obtain

parameters.setPictureFormat(PixelFormat.JPE