Android 照相机的实例应用
关键技术：
SurfaceHolder.Callback
public class MyCameraDemo extends Activity {
private SurfaceView surface = null ;
private Button but = null ;
private SurfaceHolder holder = null ;
private Camera cam = null ;
private boolean previewRunning = true ;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setContentView(R.layout.main);
this.but = (Button) super.findViewById(R.id.but) ;
this.surface = (SurfaceView) super.findViewById(R.id.surface) ;
this.holder = this.surface.getHolder() ;
this.holder.addCallback(new MySurfaceViewCallback()) ;
//设置缓冲类型
this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS) ;
//设置分辨率
this.holder.setFixedSize(600, 350);
this.but.setonClickListener(new onClickListenerImpl()) ;
}
private class onClickListenerImpl implements onClickListener {
@Override
public void onClick(View v) {
if(MyCameraDemo.this.cam != null) {
//自动对焦
MyCameraDemo.this.cam.autoFocus(new AutoFocusCallbackImpl()) ;
}
}
}
private class MySurfaceViewCallback implements SurfaceHolder.Callback {
//当预览界面格式大小改变时，调用
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
}
//初次实例化界面调用
public void surfaceCreated(SurfaceHolder holder) {
MyCameraDemo.this.cam = Camera.open(0) ; // 取得第一个摄像头
//窗口服务
WindowManager manager = (WindowManager) MyCameraDemo.this
.getSystemService(Context.WINDOW_SERVICE);
//取得display显示对象
Display display = manager.getDefaultDisplay() ;
//照相机参数
Parameters param = MyCameraDemo.this.cam.getParameters() ;
//将照相机预览大小设置为display大小
param.setPreviewSize(display.getWidth(), display.getHeight()) ;
param.setPreviewframeRate(5) ; // 一秒5帧
param.setPictureFormat(PixelFormat.JPEG) ; // 图片形式
param.set("jpen-quality", 80) ;//图片质量，最高100
MyCameraDemo.this.cam.setParameters(param) ;
try {
MyCameraDemo.this.cam.setPreviewDisplay(MyCameraDemo.this.holder) ;
} catch (IOException e) {
}
MyCameraDemo.this.cam.startPreview() ; // 进行预览
MyCameraDemo.this.previewRunning = true ; // 已经开始预览
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
if(MyCameraDemo.this.cam != null) {
if(MyCameraDemo.this.previewRunning) {
MyCameraDemo.this.cam.stopPreview() ; // 停止预览
MyCameraDemo.this.previewRunning = false ;
}
MyCameraDemo.this.cam.release() ;
}
}
}
private class AutoFocusCallbackImpl implements AutoFocusCallback {
@Override
public void onAutoFocus(boolean success, Camera camera) {
if(success) { // 成功
MyCameraDemo.this.cam.takePicture(sc, pc, jpgcall) ;
}
}
}
private PictureCallback jpgcall = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) { // 保存图片的操作
Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);
String fileName = Environment.getExternalStorageDirectory()
.toString()
+ File.separator
+ "mldnphoto"
+ File.separator
+ "MLDN_" + System.currentTimeMillis() + ".jpg";
File file = new File(fileName) ;
if (!file.getParentFile().exists()) {
file.getParentFile().mkdirs() ; // 创建文件夹
}
try {
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file)) ;
bmp.compress(Bitmap.CompressFormat.JPEG, 80, bos) ; // 向缓冲区之中压缩图片
bos.flush() ;
bos.close() ;
Toast.makeText(MyCameraDemo.this,
"拍照成功，照片已保存在" + fileName + "文件之中！", Toast.LENGTH_SHORT)
.show();
} catch (Exception e) {
Toast.makeText(MyCameraDemo.this,
"拍照失败！", Toast.LENGTH_SHORT)
.show();
}
MyCameraDemo.this.cam.stopPreview() ;
MyCameraDemo.this.cam.startPreview() ;
}
} ;
private ShutterCallback sc = new ShutterCallback(){
@Override
public void onShutter() {
// 按下快门之后进行的操作
}
} ;
private PictureCallback pc = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
}
} ;
}
主布局函数
以上就是Android 相机的使用方法，如有疑问请留言或者到本站社区交流讨论，感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！
