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);
}
}