多媒体 camera 拍照

多媒体 camera 拍照

Android应用提供Camera来控制拍照，按如下步骤：

1. 调用Camera的open（）方法打开相机

2.调用Camera的getParameter（）方法来获取拍照参数。该方法返回一个Camera.Parameter对象

3.调用Camera的SetParameter（），并将Camera.Parameter对象作为参数传入，这样可以控制相机的参数。

4.调用Camera的startPreview（）方法开始预览取景，在预览取景之前需要调用Camera的setPreviewDisplay（surfaceHolder holder）防范设置使用哪个SurfaceView来显示取景图片

5.调用Camera的takePicture（）方法进行拍照

6.结束程序时，调用Camera的stopPreview（）来结束取景预览，并调用release释放资源

package com.example.captureimage;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import android.support.v7.app.ActionBarActivity;

import android.support.v7.app.AlertDialog;

import android.content.DialogInterface;

import android.content.DialogInterface.OnClickListener;

import android.graphics.Bitmap;

import android.graphics.Bitmap.CompressFormat;

import android.graphics.BitmapFactory;

import android.graphics.PixelFormat;

import android.hardware.Camera;

import android.hardware.Camera.PictureCallback;

import android.os.Bundle;

import android.os.Environment;

import android.util.Log;

import android.view.Display;

import android.view.KeyEvent;

import android.view.Menu;

import android.view.MenuItem;

import android.view.SurfaceHolder;

import android.view.SurfaceHolder.Callback;

import android.view.SurfaceView;

import android.view.View;

import android.view.Window;

import android.view.WindowManager;

import android.widget.EditText;

import android.widget.ImageView;

public class MainActivity extends ActionBarActivity {

SurfaceView sView;

SurfaceHolder surfaceHolder;

int screenWidth,screenHeight;

Camera camera;

boolean isPreview = false ;

@Override

protected void onCreate(Bundle savedInstanceState) {

requestWindowFeature(Window.FEATURE_NO_TITLE);

super.onCreate(savedInstanceState);

getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

setContentView(R.layout.activity_main);

WindowManager wm = (WindowManager)getSystemService(WINDOW_SERVICE);

Display display = wm.getDefaultDisplay();

//get height and weight

screenHeight = display.getHeight();

screenWidth = display.getWidth();

System.out.print("wanlihua debug screen height and width :" + screenHeight + ","+screenWidth);

//get surfaceView and surfaceHolder

sView = (SurfaceView)findViewById(R.id.surfaceView1);

surfaceHolder = sView.getHolder();

surfaceHolder.addCallback(new Callback() {

@Override

public void surfaceDestroyed(SurfaceHolder holder) {

// TODO Auto-generated method stub

}

@Override

public void surfaceCreated(SurfaceHolder holder) {

// TODO Auto-generated method stub

initCamera();

}

@Override

public void surfaceChanged(SurfaceHolder holder, int format, int width,

int height) {

// TODO Auto-generated method stub

/*if(camera != null){

if(isPreview){

camera.stopPreview();

}

camera.release();

camera = null;

}*/

}

});

surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

}

private void initCamera() {

if(!isPreview)

camera = Camera.open();

if(camera != null && !isPreview){

try {

Camera.Parameters parameters = camera.getParameters();

parameters.setPreviewSize(screenHeight,screenWidth);

parameters.setPreviewFrameRate(4);

parameters.setPictureFormat(PixelFormat.JPEG);

parameters.set("jpeg-quality",85);

parameters.setPictureSize(screenHeight,screenWidth);

parameters.setRotation(90);

camera.setParameters(parameters);

camera.setPreviewDisplay(surfaceHolder);

camera.setDisplayOrientation(90); //setCameraDisplayOrientation();

camera.startPreview();

camera.autoFocus(null);

} catch (Exception e) {

// TODO: handle exception

e.printStackTrace();

}

isPreview = true;

}

}

@Override

public boolean onKeyDown(int keyCode, KeyEvent event) {

// TODO Auto-generated method stub

switch (keyCode) {

case KeyEvent.KEYCODE_CAMERA:

case KeyEvent.KEYCODE_VOLUME_UP:

case KeyEvent.KEYCODE_VOLUME_DOWN:

if(camera != null && event.getRepeatCount() == 0){

camera.takePicture(null, null, myjpegCallback);

return true;

}

break;

default:

break;

}

return super.onKeyDown(keyCode, event);

}

PictureCallback myjpegCallback = new PictureCallback() {

@Override

public void onPictureTaken(byte[] data, Camera camera) {

// TODO Auto-generated method stub

//根据拍照所得数据创建位图

final Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);

//加载、layout/save.xml文件对应布局资源

View saveDiag = getLayoutInflater().inflate(R.layout.save, null);

final EditText photoName = (EditText)saveDiag.findViewById(R.id.photo_name);

//get dialog imageview comp

ImageView show = (ImageView)saveDiag.findViewById(R.id.show);

show.setImageBitmap(bmp);

new AlertDialog.Builder(MainActivity.this).setView(saveDiag).setPositiveButton("store", new OnClickListener() {

@Override

public void onClick(DialogInterface dialog, int which) {

// TODO Auto-generated method stub

//create sdcard file

File file = new File(Environment.getExternalStorageDirectory(), photoName.getText().toString()+".jpg");

file = new File(Environment.getExternalStorageDirectory()+"/DCIM/Camera/" + photoName.getText().toString()+".jpg" );

Log.d("wanlihua", "wanlihua debug File : "+ file);

try {

FileOutputStream outstream = new FileOutputStream(file);

Log.d("wanlihua", "wanlihua debug outstream : "+ outstream);

bmp.compress(CompressFormat.JPEG, 100, outstream);

outstream.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}).setNegativeButton("cancel", null).show();

camera.stopPreview();

camera.startPreview();

isPreview = true ;

}

};

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

@Override

public boolean onOptionsItemSelected(MenuItem item) {

// Handle action bar item clicks here. The action bar will

// automatically handle clicks on the Home/Up button, so long

// as you specify a parent activity in AndroidManifest.xml.

int id = item.getItemId();

if (id == R.id.action_settings) {

return true;

}

return super.onOptionsItemSelected(item);

}

}