微信上微网站怎么做的,网站空间是什么意思,永州企业网站建设价格,安装网站模版视频教程http://blog.csdn.net/jason0539/article/details/10125017 android之相机开发 分类#xff1a; android 基础知识2013-08-20 22:32 9774人阅读 评论(2) 收藏 举报Android在android中应用相机功能#xff0c;一般有两种#xff1a;一种是直接调用系统相机#xff0c;一种自… http://blog.csdn.net/jason0539/article/details/10125017 android之相机开发 分类 android 基础知识2013-08-20 22:32 9774人阅读 评论(2) 收藏 举报 Android 在android中应用相机功能一般有两种一种是直接调用系统相机一种自己写的相机。我将分别演示两种方式的使用第一种是使用Intent跳转到系统相机,action为:android.media.action.STILL_IMAGE_CAMERA关键代码 [java] view plaincopyprint? Intent intent new Intent(); //调用照相机 intent.setAction(android.media.action.STILL_IMAGE_CAMERA); startActivity(intent); 例子: [java] view plaincopyprint? import android.app.Activity; import android.content.Intent; import android.os.Bundle; public class CameraTest_2 extends Activity { /** Called when the activity is first created. */ Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Intent intent new Intent(); //调用照相机 intent.setAction(android.media.action.STILL_IMAGE_CAMERA); startActivity(intent); } } 想要测试的可以直接新建一个项目并且把主activity的代码换成上面的然后运行我测试了一下上面这个代码并不需要权限毕竟只是调用系统自带的程序。当然网上还有一些其他相关的调用方法只要设置对了action,那么系统就会调用系统自带的相机. 第二种:1首先我们要自己创建一个照相界面必须考虑用什么控件显示照相机中的预览效果显然android已经帮我们做好了选择那就是SurfaceView 控制SurfaceView需要一个surfaceHolder,他是系统提供的一个用来设置SurfaceView的一个对象可以通过surfaceView.getHolder()这个方法来获得. Camera提供一个setPreviewDisplay(SurfaceHolder)的方法来连接surfaceHolder,并通过他来控制surfaceView. 而我们则使用android的Camera类提供了startPreview()和stopPreview()来开启和关闭预览.关系如下Camera -- --SurfaceHolder------SurfaceView. 2知道怎么预览了当然也要知道怎么开启相机.Camera.open()这是个静态方法如果相机没有别人用着则会返回一个 相机引用如果被人用着则会抛出异常。很奇怪的是这个方法不能随便放如放在构造方法或者onCreate()方法中都会照成没有预览效果. 3SurfaceHolder.Callback,这是个holder用来显示surfaceView 数据的接口,他分别必须实现3个方法surfaceCreated()这个方法是surface 被创建后调用的surfaceChanged()这个方法是当surfaceView发生改变后调用的surfaceDestroyed()这个是当surfaceView销毁时调用的.surfaceHolde通过addCallBack()方法将响应的接口绑定到他身上.surfaceHolder还必须设定一个setType()方法查看api的时候发现这个方法已经过时但是不写又会报错 4我用以上知识写了一个MySurfaceView类他继承于SurfaceView,并在里面实现了照相机的预览功能.这个我觉得最简单的照相机预览代码:MySurfaceView.java: [java] view plaincopyprint? import java.io.IOException; import android.content.Context; import android.graphics.PixelFormat; import android.hardware.Camera; import android.util.Log; import android.view.SurfaceHolder; import android.view.SurfaceView; public class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback{ SurfaceHolder holder; Camera myCamera; public MySurfaceView(Context context) { super(context); holder getHolder();//获得surfaceHolder引用 holder.addCallback(this); holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//设置类型 } Override public void surfaceCreated(SurfaceHolder holder) { // TODO Auto-generated method stub if(myCamera null) { myCamera Camera.open();//开启相机,不能放在构造函数中不然不会显示画面. try { myCamera.setPreviewDisplay(holder); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { myCamera.startPreview(); } Override public void surfaceDestroyed(SurfaceHolder holder) { // TODO Auto-generated method stub myCamera.stopPreview();//停止预览 myCamera.release();//释放相机资源 myCamera null; Log.d(ddd, 4); } } 主activity代码: [java] view plaincopyprint? import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; public class CameraTest_3 extends Activity { /** Called when the activity is first created. */ MySurfaceView mySurface; Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mySurface new MySurfaceView(this); setContentView(mySurface); } } 而且必须给应用添加权限: [html] view plaincopyprint? uses-permission android:nameandroid.permission.CAMERA/uses-permission (5)能够预览了接下来就是拍照了拍照用到了一个camera.tackPiture()这个方法,这个方法有三个参数分别是ShutterCallBack shutter,PictureCallBack raw,PictureCallBack jpeg.下面是对他们的实现 [java] view plaincopyprint? private ShutterCallback shutter new ShutterCallback() { Override public void onShutter() { // TODO Auto-generated method stub Log.d(ddd, shutter); } }; private PictureCallback raw new PictureCallback() { Override public void onPictureTaken(byte[] data, Camera camera) { // TODO Auto-generated method stub Log.d(ddd, raw); } }; private PictureCallback jpeg new PictureCallback() { Override public void onPictureTaken(byte[] data, Camera camera) { // TODO Auto-generated method stub Log.d(ddd,jpeg); } }; 当开始拍照时会依次调用shutter的onShutter()方法raw的onPictureTaken方法,jpeg的onPictureTaken方法.三个参数的作用是shutter--拍照瞬间调用raw--获得没有压缩过的图片数据jpeg---返回jpeg的图片数据当你不需要对照片进行处理可以直接用null代替.注意当调用camera.takePiture方法后camera关闭了预览这时需要调用startPreview()来重新开启预览。 我用以上知识加到上面的那个例子就形成了下面的代码MySurfaceView.java: [java] view plaincopyprint? package jason.camera; import java.io.IOException; import android.content.Context; import android.graphics.PixelFormat; import android.hardware.Camera; import android.hardware.Camera.PictureCallback; import android.hardware.Camera.ShutterCallback; import android.util.Log; import android.view.SurfaceHolder; import android.view.SurfaceView; public class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback{ SurfaceHolder holder; Camera myCamera; private ShutterCallback shutter new ShutterCallback() { Override public void onShutter() { // TODO Auto-generated method stub Log.d(ddd, shutter); } }; private PictureCallback raw new PictureCallback() { Override public void onPictureTaken(byte[] data, Camera camera) { // TODO Auto-generated method stub Log.d(ddd, raw); } }; private PictureCallback jpeg new PictureCallback() { Override public void onPictureTaken(byte[] data, Camera camera) { // TODO Auto-generated method stub Log.d(ddd,jpeg); } }; public MySurfaceView(Context context) { super(context); holder getHolder();//获得surfaceHolder引用 holder.addCallback(this); holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//设置类型 } public void tackPicture() { myCamera.takePicture(null,null,null); } public void voerTack() { myCamera.startPreview(); } Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { myCamera.startPreview(); } Override public void surfaceCreated(SurfaceHolder holder) { // TODO Auto-generated method stub if(myCamera null) { myCamera Camera.open();//开启相机,不能放在构造函数中不然不会显示画面. try { myCamera.setPreviewDisplay(holder); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } Override public void surfaceDestroyed(SurfaceHolder holder) { // TODO Auto-generated method stub myCamera.stopPreview();//停止预览 myCamera.release();//释放相机资源 myCamera null; } } 主activity: [java] view plaincopyprint? import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; public class CameraTest_3 extends Activity implements OnClickListener { /** Called when the activity is first created. */ MySurfaceView mySurface; boolean isClicked false; Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mySurface new MySurfaceView(this); setContentView(mySurface); mySurface.setOnClickListener(this); } Override public void onClick(View v) { // TODO Auto-generated method stub if(!isClicked) { mySurface.tackPicture(); isClicked true; }else { mySurface.voerTack(); isClicked false; } } 这样就是实现了拍照的功能那么怎样要图片保存呢那么这是就需要在那个参数中的jpeg的方法里面进行处理了那个方法的data参数就是相片的数据。我们通过BitmapFactory.decodeByteArray(data, 0, data.length)来获得图片并通过io处理将图片保存到想要保存的位置下面这段代码是将照片保存到/sdcard/wjh.jpg;并把一些没有用到的代码全部删掉剩下一些必须的代码 [java] view plaincopyprint? package java.camera; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.PixelFormat; import android.hardware.Camera; import android.hardware.Camera.PictureCallback; import android.hardware.Camera.ShutterCallback; import android.util.Log; import android.view.SurfaceHolder; import android.view.SurfaceView; public class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback{ SurfaceHolder holder; Camera myCamera; private PictureCallback jpeg new PictureCallback() { Override public void onPictureTaken(byte[] data, Camera camera) { // TODO Auto-generated method stub try { Bitmap bm BitmapFactory.decodeByteArray(data, 0, data.length); File file new File(/sdcard/wjh.jpg); BufferedOutputStream bos new BufferedOutputStream(new FileOutputStream(file)); bm.compress(Bitmap.CompressFormat.JPEG,100,bos); bos.flush(); bos.close(); }catch(Exception e) { e.printStackTrace(); } } }; public MySurfaceView(Context context) { super(context); holder getHolder();//获得surfaceHolder引用 holder.addCallback(this); holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//设置类型 } public void tackPicture() { myCamera.takePicture(null,null,jpeg); } public void voerTack() { myCamera.startPreview(); } Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { myCamera.startPreview(); } Override public void surfaceCreated(SurfaceHolder holder) { // TODO Auto-generated method stub if(myCamera null) { myCamera Camera.open();//开启相机,不能放在构造函数中不然不会显示画面. try { myCamera.setPreviewDisplay(holder); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } Override public void surfaceDestroyed(SurfaceHolder holder) { // TODO Auto-generated method stub myCamera.stopPreview();//停止预览 myCamera.release();//释放相机资源 myCamera null; } } 注意这是必须添加在sd卡上写数据的权限 [html] view plaincopyprint? uses-permission android:nameandroid.permission.WRITE_EXTERNAL_STORAGE/ (7)能够拍照了这下子要考虑如何让图片更好看了这显然是专业人士的强项但是我们在程序上也可以做一些处理向上面的那些因为我直接把surfaceView当做整体布局就可能出现屏幕被拉开了不是很好看所以这时就可以不要把surfaceView弄成整体布局把他弄到一个布局管理器再设置相关的参数.这时需要注意的是有些参数不能随便乱设如以下代码: [java] view plaincopyprint? Camera.Parameters parames myCamera.getParameters();//获得参数对象 parames.setPictureFormat(PixelFormat.JPEG);//设置图片格式 parames.setPreviewSize(640,480);//这里面的参数只能是几个特定的参数否则会报错.(176*144,320*240,352*288,480*360,640*480) myCamera.setParameters(parames); 还有自动对焦当然有些手机没有这个功能自动对焦是通过autoFocus()这个方法调用一个自动对焦的接口并在里面进行处理。注意这个方法必须在startPreview()和stopPreview()中间。AutoFocusCallback是自动对焦的接口实现它必须实现public void onAutoFocus(boolean success, Camera camera)这个方法所以我们可以将拍照方法放在这里面然后对焦后再进行拍摄。。效果会好很多。注意自动对焦需要添加 [html] view plaincopyprint? uses-feature android:nameandroid.hardware.camera.autofocus / 下面是主要代码,直接贴出来了 [java] view plaincopyprint? import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import android.app.Activity; import android.content.pm.ActivityInfo; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.PixelFormat; import android.hardware.Camera; import android.hardware.Camera.AutoFocusCallback; import android.hardware.Camera.PictureCallback; import android.os.Bundle; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.View; import android.view.Window; import android.view.SurfaceHolder.Callback; import android.view.View.OnClickListener; public class CameraTest_4 extends Activity implements Callback, OnClickListener, AutoFocusCallback{ SurfaceView mySurfaceView;//surfaceView声明 SurfaceHolder holder;//surfaceHolder声明 Camera myCamera;//相机声明 String filePath/sdcard/wjh.jpg;//照片保存路径 boolean isClicked false;//是否点击标识 //创建jpeg图片回调数据对象 PictureCallback jpeg new PictureCallback() { Override public void onPictureTaken(byte[] data, Camera camera) { // TODO Auto-generated method stub try {// 获得图片 Bitmap bm BitmapFactory.decodeByteArray(data, 0, data.length); File file new File(filePath); BufferedOutputStream bos new BufferedOutputStream(new FileOutputStream(file)); bm.compress(Bitmap.CompressFormat.JPEG, 100, bos);//将图片压缩到流中 bos.flush();//输出 bos.close();//关闭 }catch(Exception e) { e.printStackTrace(); } } }; /** Called when the activity is first created. */ Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE);//无标题 //设置拍摄方向 this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); setContentView(R.layout.main); //获得控件 mySurfaceView (SurfaceView)findViewById(R.id.surfaceView1); //获得句柄 holder mySurfaceView.getHolder(); //添加回调 holder.addCallback(this); //设置类型 holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); //设置监听 mySurfaceView.setOnClickListener(this); } Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { // TODO Auto-generated method stub //设置参数并开始预览 Camera.Parameters params myCamera.getParameters(); params.setPictureFormat(PixelFormat.JPEG); params.setPreviewSize(640,480); myCamera.setParameters(params); myCamera.startPreview(); } Override public void surfaceCreated(SurfaceHolder holder) { // TODO Auto-generated method stub //开启相机 if(myCamera null) { myCamera Camera.open(); try { myCamera.setPreviewDisplay(holder); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } Override public void surfaceDestroyed(SurfaceHolder holder) { // TODO Auto-generated method stub //关闭预览并释放资源 myCamera.stopPreview(); myCamera.release(); myCamera null; } Override public void onClick(View v) { // TODO Auto-generated method stub if(!isClicked) { myCamera.autoFocus(this);//自动对焦 isClicked true; }else { myCamera.startPreview();//开启预览 isClicked false; } } Override public void onAutoFocus(boolean success, Camera camera) { // TODO Auto-generated method stub if(success) { //设置参数,并拍照 Camera.Parameters params myCamera.getParameters(); params.setPictureFormat(PixelFormat.JPEG); params.setPreviewSize(640,480); myCamera.setParameters(params); myCamera.takePicture(null, null, jpeg); } } } main.xml: [html] view plaincopyprint? linearlayout xmlns:androidhttp://schemas.android.com/apk/res/android androidrientationvertical android:layout_widthfill_parent android:layout_heightfill_parent surfaceview android:idid/surfaceView1 android:layout_width640px android:layout_height480px android:layout_gravitycenter AndroidManifest.xml: [html] view plaincopyprint? ?xml version1.0 encodingutf-8? manifest xmlns:androidhttp://schemas.android.com/apk/res/android packagecom.wjh.camera android:versionCode1 android:versionName1.0 uses-sdk android:minSdkVersion7 / uses-permission android:nameandroid.permission.CAMERA/uses-permission uses-feature android:nameandroid.hardware.camera.autofocus / uses-permission android:nameandroid.permission.WRITE_EXTERNAL_STORAGE/ application android:icondrawable/icon android:labelstring/app_name activity android:name.CameraTest_4 android:labelstring/app_name intent-filter action android:nameandroid.intent.action.MAIN / category android:nameandroid.intent.category.LAUNCHER / /intent-filter /activity /application /manifest PS:其实自己去实现相机的必要性不大,大部分应用都是直接调用系统的相机,毕竟相机是涉及到一些比较专业的成像知识. 转载于:https://www.cnblogs.com/qingchen1984/p/4766395.html
