Android 如何从其他类(摄影机)获取当前路径
我正在开发一个应用程序,从我的自定义相机类中拍摄照片,然后获取路径并将其放入活动的imageView中,就像预览图像一样,现在我创建了一个类来处理相机功能,并将预览结果的路径发送给活动。但我的结果并不是我捕捉到的正确图片。示例:第一次拍照时,我的“currentPicpath”为空,但第二次拍照时,它给出了我之前拍摄的第一张图像 因此,在第2类中,我创建了一个方法,该方法获取当前路径,但除非拍摄新图片,否则不会给出null 还有一个问题,为什么图像保存后会出现相反的情况? 我的班级:Android 如何从其他类(摄影机)获取当前路径,android,path,android-camera,Android,Path,Android Camera,我正在开发一个应用程序,从我的自定义相机类中拍摄照片,然后获取路径并将其放入活动的imageView中,就像预览图像一样,现在我创建了一个类来处理相机功能,并将预览结果的路径发送给活动。但我的结果并不是我捕捉到的正确图片。示例:第一次拍照时,我的“currentPicpath”为空,但第二次拍照时,它给出了我之前拍摄的第一张图像 因此,在第2类中,我创建了一个方法,该方法获取当前路径,但除非拍摄新图片,否则不会给出null 还有一个问题,为什么图像保存后会出现相反的情况? 我的班级: MainA
MainActivity:
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.dialog_additem);
d_image_pre1 = (ImageView) findViewById(R.id.d_image1);
d_BTakePicture = (Button) findViewById(R.id.d_bTakePicture);
bOpenCamera = (Button) findViewById(R.id.bOpenCamera);
d_BTakePicture.setOnClickListener(this);
bOpenCamera.setOnClickListener(this);
take = new TakeApicture(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.bOpenCamera:
take.openCam();
break;
case R.id.d_bTakePicture:
take.makeFolder("myTest");
take.captureImage();
String path = take.getCurrentPicPath();
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2;
Bitmap bm = BitmapFactory.decodeFile(path, options);
d_image_pre1.setImageBitmap(bm);
break;
default:
break;
}
}
第2类:
public class TakeApicture implements SurfaceHolder.Callback{
Activity context;
Camera camera;
SurfaceView surface;
SurfaceHolder holder;
PictureCallback jpegCallback;
File myGeneralFolder;
FileOutputStream outStream = null;
private String fullPathFolder;
String currentPicPath = "No image path";
@SuppressWarnings("deprecation")
public TakeApicture(Activity context) {
super();
this.context = context;
surface = (SurfaceView)context.findViewById(R.id.surfaceView);
holder = surface.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
jpegCallBack();
}
public void captureImage() {
camera.takePicture(null, null, jpegCallback);
}
public void makeFolder(String itemFolderName) {
fullPathFolder = Environment.getExternalStorageDirectory()+File.separator+"mySalesImages"+File.separator+itemFolderName;
myGeneralFolder = new File(fullPathFolder);
myGeneralFolder.mkdirs();
}
public void jpegCallBack(){
jpegCallback = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
try {
getPicPath(data);
} catch (IOException e) {
e.printStackTrace();
}
}
};
}
public void getPicPath(byte[] data) throws IOException{
currentPicPath = String.format(myGeneralFolder+"/%d.jpg",(System.currentTimeMillis()));
outStream = new FileOutputStream(currentPicPath);
outStream.write(data);
outStream.close();
}
public String getCurrentPicPath() {
return currentPicPath;
}
@SuppressWarnings("deprecation")
public void openCam(){
try {
camera = Camera.open();
Camera.Parameters param;
param = camera.getParameters();
//modify parameter
camera.setDisplayOrientation(90);
param.setPreviewFrameRate(20);
param.setPreviewSize(176, 144);
camera.setParameters(param);
camera.setPreviewDisplay(holder);
camera.startPreview();
} catch (Exception e) {
// TODO: handle exception
}
}
public void closeCam(){
camera.stopPreview();
camera.release();
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
closeCam();
}
}
这是正确的解决方案???
take.captureImage();
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
String path = take.getCurrentPicPath();
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2;
Bitmap bm = BitmapFactory.decodeFile(path, options);
d_image_pre1.setImageBitmap(bm);
}
}, 1000);
行
take.captureImage()代码>启动捕获照片的异步过程。一段时间后,Android系统将调用您的onPictureTaken()
回调,您将计算一个新的图像路径(并相应地写入照片)。但是这条线
String path = take.getCurrentPicPath();
已经被执行了
您可以同步计算路径,但即使如此,您的活动也必须等待实际映像写入磁盘。因此,您别无选择,只能提取该片段
String path = take.getCurrentPicPath();
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2;
Bitmap bm = BitmapFactory.decodeFile(path, options);
d_image_pre1.setImageBitmap(bm);
转换为单独的方法。您可以直接从onPictureTaken()
调用此新方法,也可以使用post()
(无需从onPictureTaken()
调用postDelayed()
)异步执行它
因此,快速而肮脏的修复(为简洁起见删除了异常处理)如下所示:
在MainActivity.java中:
public void onClick(View v) {
switch (v.getId()) {
case R.id.bOpenCamera:
take.openCam();
break;
case R.id.d_bTakePicture:
take.makeFolder("myTest");
take.captureImage();
break;
}
}
public void setImage(String path) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2;
Bitmap bm = BitmapFactory.decodeFile(path, options);
d_image_pre1.setImageBitmap(bm);
}
public void jpegCallBack() {
jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
getPicPath(data);
(MainActivity)context.setImage(currentPicPath);
}
};
}
在takeapiture.java中:
public void onClick(View v) {
switch (v.getId()) {
case R.id.bOpenCamera:
take.openCam();
break;
case R.id.d_bTakePicture:
take.makeFolder("myTest");
take.captureImage();
break;
}
}
public void setImage(String path) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2;
Bitmap bm = BitmapFactory.decodeFile(path, options);
d_image_pre1.setImageBitmap(bm);
}
public void jpegCallBack() {
jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
getPicPath(data);
(MainActivity)context.setImage(currentPicPath);
}
};
}
你是说在异步任务中?!不,只需使用一些处理程序.post()
。AsyncTask在这里是不相关的,因为必须在UI线程上更新ImageView。我编辑了我的问题的某些部分,请查看并告诉我这是否是正确的做法。虽然您所做的更改大部分都能完成任务,但有时会失败(在某些设备上捕获可能需要1秒以上),并在其他情况下引入不必要的延迟(在大多数设备上,捕获比1s快得多)。我在我的第二个解决方案中,我刚刚将位图解码到捕获类中,它工作得很好。但是当我尝试快速点击按钮时,它崩溃了:06-19 13:58:00.046:E/AndroidRuntime(7918):致命异常:main 06-19 13:58:00.046:E/AndroidRuntime(7918):java.lang.RuntimeException:takePicture失败06-19 13:58:00.046:E/AndroidRuntime(7918):在