摄像头(4)用Camera和SurfaceView自定义拍照程序

import android.app.Activity;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.Window;
import android.view.WindowManager; /*
* 定制拍照程序
* 注意Camera从5.0开始过期.用Camera2
*/
public class CustomCameraActivity extends Activity { //定制拍照 第1步,加权限 //定制拍照 第2步,准备相关api
private Camera mCamera;//用来拍照 private Preview mPreview;//用来预览和处理拍照事件.它是一个自定义surfaceView @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState); //定制拍照 第3步,设置全屏.
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN); } protected void onResume() {
super.onResume();
//定制拍照 第4步, 打开 Camera并得到Camera实例,注意这是独占的,打开后其它程序不能打开.
mCamera = Camera.open();
mPreview.setCamera(mCamera); //定制拍照 第5步,构造预览view,这是一个自定义的surfaceView,拍照事件,及预览都在它内部实现.
mPreview = new Preview(this);
setContentView(mPreview);
} //定制拍照 第6步,释放camera
@Override
protected void onPause() {
super.onPause(); if (mCamera != null) {
mCamera.release();
mCamera = null;
mPreview.setCamera(null);
}
} //检测Android设备是否支持照相机
private boolean checkCameraHardware(){
if (getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
return true;
}else{
return false;
}
}
}

import java.io.File;
import java.io.FileOutputStream;
import java.util.List; import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.Size;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener; /*
* 它是一个自定义surfaceView,
* 用来预览和处理拍照事件.
* 注意它实现的接口
*/
class Preview extends ViewGroup implements SurfaceHolder.Callback,OnClickListener { //自定义预览和处理拍照事件 第1步, 准备相关成员
SurfaceView mSurfaceView; //surface view
SurfaceHolder mHolder; //SurfaceHolder
Size mPreviewSize; //当前预览窗口尺寸.
List<Size> mSupportedPreviewSizes; //当前设备支持的所有预览尺寸
Camera mCamera; //摄像头对象
Context mContext; //上下文 public Preview(Context context) {
super(context);
mContext = context; //自定义预览和处理拍照事件 第2步,创建surface view
mSurfaceView = new SurfaceView(context);
addView(mSurfaceView);
//自定义预览和处理拍照事件 第3步,得到 SurfaceHolder
mHolder = mSurfaceView.getHolder(); //自定义预览和处理拍照事件 第4步,添加SurfaceHolder回调
mHolder.addCallback(this);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
//自定义预览和处理拍照事件 第5步,得到支持的预览尺寸,注意Camera是在本类外打开的.
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPictureSizes();
//更新 layout
requestLayout();
}
}
//from SurfaceHolder.Callback
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
if (mCamera != null) {
//自定义预览和处理拍照事件 第6步,在SurfaceView创建时,设置camera的预览view
mCamera.setPreviewDisplay(holder);
}
} catch (Exception e) {
} }
//from SurfaceHolder.Callback
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
if (mCamera != null) {
//自定义预览和处理拍照事件 第7步,在SurfaceView销毁时,停止预览
mCamera.stopPreview();
}
}
//from SurfaceHolder.Callback
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
//自定义预览和处理拍照事件 第8步,在SurfaceView窗口大小变化时,设置预览尺寸,大小不可随意写.
//一定要注意 预览尺寸不是实际尺寸,
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height); mCamera.setParameters(parameters);
mCamera.startPreview(); }
//from ViewGroup
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
//自定义预览和处理拍照事件 第9步,是本类是ViewGroup,预览view是它上面的一个view,这里设置ViewGroup的layout
if (changed && getChildCount() > ) {
final View child = getChildAt(); int parentWidth = r - l;
int parentHeight = b - t; int previewWidth = parentWidth;
int previewHeight = parentHeight; if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
//外层的宽高比大于采集预览的宽高比.
if (parentWidth * previewHeight > parentHeight * previewWidth) {
final int scaledChildWidth = previewWidth * parentHeight
/ previewHeight;
// child.layout((width - scaledChildWidth)/2,
// 0,(width+scaledChildWidth)/2,height); //child 就是surface view
child.layout(, , , );
} else {
final int scaledChildHeight = previewHeight * parentWidth
/ previewWidth;
//child 就是surface view
child.layout(, (parentHeight - scaledChildHeight) / , parentWidth,
(parentHeight + scaledChildHeight) / );
} } }
//自定义预览和处理拍照事件 第10步,从所有预览尺寸中选一个最优的.
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
double ASPECT_TOLERANCE = 0.1;
double targetRatio = w / h;
if (sizes == null)
return null; Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h; for (Size size : sizes) {
double ratio = size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) {
continue;
}
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
} if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
} //自定义预览和处理拍照事件 第11步,在onMeasure中处理最佳预览尺寸
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = resolveSize(getSuggestedMinimumWidth(),
widthMeasureSpec);
int height = resolveSize(getSuggestedMinimumHeight(),
heightMeasureSpec); setMeasuredDimension(width, height); if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes,width, height);
}
}
//自定义预览和处理拍照事件 第12步, 在预览view上点击屏幕时,拍照
//注意回调函数
public void onClick(View view) {
//它是异步的.
mCamera.takePicture(null, null, mPictureCallback);
} //自定义预览和处理拍照事件 第13步, 拍照的回调.
private PictureCallback mPictureCallback = new PictureCallback() { @Override
public void onPictureTaken(byte[] data, Camera camera) {
mCamera.startPreview();//再次启动预览,这步可选.
File pictureFile = new File("/sdcard/image.jpg");
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (Exception e) {
}
}
};
}