更新了更多代码
我试图抓取刚拍摄的照片并以编程方式将其设置为ImageView.
按下图片按钮,
picture_button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
takePhoto(mTextureView);
}
});
它运行takePhoto方法：
public void takePhoto(View view) {
try {
mImageFile = createImageFile();
final ImageView latest_picture = (ImageView) findViewById(R.id.latest_picture);
final RelativeLayout latest_picture_container = (RelativeLayout) findViewById(R.id.latest_picture_container);
final String mImageFileLocationNew = mImageFileLocation.replaceFirst("^/","");
Toast.makeText(getApplicationContext(),"" + mImageFile,Toast.LENGTH_SHORT).show();
Uri uri = Uri.fromFile(mImageFile);
Toast.makeText(getApplicationContext(),""+uri,Toast.LENGTH_LONG).show();
latest_picture.setImageURI(uri);
latest_picture_container.setVisibility(View.VISIBLE);
} catch (IOException e){
e.printStackTrace();
}
lockFocus();
captureStillImage();
}
运行createImageFile()和captureStillImage()
private void captureStillImage() {
try {
CaptureRequest.Builder captureStillBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
captureStillBuilder.addTarget(mImageReader.getSurface());
int rotation = getWindowManager().getDefaultDisplay().getRotation();
captureStillBuilder.set(CaptureRequest.JPEG_ORIENTATION,ORIENTATIONS.get(rotation));
CameraCaptureSession.CaptureCallback captureCallback = new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureCompleted(CameraCaptureSession session,CaptureRequest request,TotalCaptureResult result) {
super.onCaptureCompleted(session,request,result);
//Toast.makeText(getApplicationContext(),"Image Taken",Toast.LENGTH_SHORT).show();
unLockFocus();
}
};
mCameraCaptureSession.capture(captureStillBuilder.build(),captureCallback,null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
File createImageFile() throws IOException {
String timestamp = new SimpleDateFormat("yyyyMMdd").format(new Date());
String subFolder = "";
if(pref_session_unique_gallery.equals("yes")){
if(event_name != null){
subFolder = event_name;
} else {
subFolder = timestamp;
}
} else {
subFolder = "_GEN";
}
if(event_name == null){
event_name = "";
} else {
event_name = event_name + "_";
}
String imageFileName = "CPB_"+event_name+timestamp+"_";
File storageDirectory = new File(Environment.getExternalStorageDirectory() + File.separator + "CPB" + File.separator + subFolder);
storageDirectory.mkdir();
File image = File.createTempFile(imageFileName,".jpg",storageDirectory);
mImageFileLocation = image.getAbsolutePath();
return image;
}
和图像保存在这里：
private static class ImageSaver implements Runnable {
private final Image mImage;
private ImageSaver(Image image) {
mImage = image;
}
@Override
public void run() {
ByteBuffer byteBuffer = mImage.getPlanes()[0].getBuffer();
byte[] bytes = new byte[byteBuffer.remaining()];
byteBuffer.get(bytes);
FileOutputStream fileOutputStream = null;
try {
fileOutputStream = new FileOutputStream(mImageFile);
fileOutputStream.write(bytes);
} catch (IOException e) {
e.printStackTrace();
} finally {
mImage.close();
if(fileOutputStream != null){
try {
fileOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
我在createImageFile()之后获取了正确的图像路径并将其烘烤以显示每次都是什么.但即使是latest_picture_container上的setVisibility也没有工作……如果我注释掉InputStream,Bitmap和setImageBitmap,那么latest_picture_container就会正常显示.不知道为什么这是错的.
出于某种原因,URI在文件后面会有三个斜杠,
file:///storage/0/...
最佳答案
AssetManager#open()方法仅适用于您应用的资产;即项目的/ assets文件夹中的文件.由于您尝试打开外部文件,因此应该在从路径创建的File对象上使用FileInputStream.此外,takePhoto()方法在将任何内容写入文件之前在ImageView上设置图像,这将导致空的ImageView.
由于您的应用程序直接使用相机,我们可以从正在写入图像文件的相同字节数组中解码图像,并为自己节省不必要的存储读取.此外,在您的代码示例中,文件写入发生在单独的线程上,因此我们不妨利用它来执行图像解码,因为它将最小化对UI线程的影响.
首先,我们将创建一个接口,ImageSaver可以通过该接口将图像传递回活动以在ImageView中显示.
public interface OnImageDecodedListener {
public void onImageDecoded(Bitmap b);
}
然后我们需要稍微改变ImageSaver类以在构造函数中获取Activity参数.我还添加了一个File参数,因此Activity的相应字段不必是静态的.
private static class ImageSaver implements Runnable {
private final Activity mActivity;
private final Image mImage;
private final File mImageFile;
public ImageSaver(Activity activity,Image image,File imageFile) {
mActivity = activity;
mImage = image;
mImageFile = imageFile;
}
@Override
public void run() {
ByteBuffer byteBuffer = mImage.getPlanes()[0].getBuffer();
byte[] bytes = new byte[byteBuffer.remaining()];
byteBuffer.get(bytes);
final Bitmap b = BitmapFactory.decodeByteArray(bytes,bytes.length);
mActivity.runOnUiThread(new Runnable() {
@Override
public void run() {
((OnImageDecodedListener) mActivity).onImageDecoded(b);
}
}
);
FileOutputStream fileOutputStream = null;
...
}
}
一旦我们在字节数组中获取图像数据,我们就将其解码并将其传递回Activity,因此它不必等待文件写入,这可以在后台安静地进行.我们需要在UI线程上调用接口方法,因为我们在那里“触摸”了视图.
Activity需要实现接口,我们可以将与视图相关的东西从takePhoto()移动到onImageDecoded()方法.
public class MainActivity extends Activity
implements ImageSaver.OnImageDecodedListener {
...
@Override
public void onImageDecoded(Bitmap b) {
final ImageView latest_picture =
(ImageView) findViewById(R.id.latest_picture);
final RelativeLayout latest_picture_container =
(RelativeLayout) findViewById(R.id.latest_picture_container);
latest_picture.setImageBitmap(b);
latest_picture_container.setVisibility(View.VISIBLE);
}
public void takePhoto(View view) {
try {
mImageFile = createImageFile();
captureStillImage();
lockFocus();
}
catch (IOException e) {
e.printStackTrace();
}
}
...
}
最后,我们需要在ImageReader的onImageAvailable()方法中实际执行ImageSaver.再次按照这个例子,它会是这样的.
private final ImageReader.OnImageAvailableListener mOnImageAvailableListener =
new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader reader) {
mBackgroundHandler.post(new ImageSaver(MainActivity.this,reader.acquireNextImage(),mImageFile)
);
}
};