我对这个问题做了很多研究，看到了一些很好的反应，并找到了一些很好的资源来解决这个问题。然而不幸的是，我仍然在某些设备上遇到很多应用程序崩溃。崩溃发生在有人拍照后，相机意图应该将信息传递回调用活动。就我的应用程序而言，我只是用新拍摄的照片覆盖任何现有照片，因此我几乎可以使用文件位置的静态路径。这就是我所说的意图：
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// get the file path from an external class (necessary for galaxy nexus)
imageFileAndPath = ImageServices.getOutputImageFileUri(cont);
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageFileAndPath);
startActivityForResult(intent, CAMERA_REQUEST_CODE);
imageFileAndPath 只是一个 URI 变量，我从一个单独的类中创建它，因为这解决了另一个问题，即按下“完成”或复选标记或在特定设备上关闭相机意图没有做任何事情几种设备类型。通过从一个单独的类创建 URI，它解决了一些未知原因的问题。
我的 onActivityResult 看起来像这样：
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(resultCode == Activity.RESULT_OK)
{
if (requestCode == CAMERA_REQUEST_CODE) {
setupImageView();
imageView = (ImageView) findViewById(R.id.image_view);
webView.setVisibility(View.GONE);
imageView.setVisibility(View.VISIBLE);
button.setVisibility(View.GONE);
reTakePicButton.setVisibility(View.VISIBLE);
rl.setVisibility(View.VISIBLE);
}
}
}
因为我不需要动态路径来保存我的照片（因为它会覆盖现有照片），所以我只需在我的活动中调用另一个方法来调整照片大小并相应地旋转它。该方法如下：
private void setupImageView() {
imageLocation = Environment.getExternalStorageDirectory().getAbsolutePath() + "/myappphoto/myappphoto.jpg";
// Get the dimensions of the View
Display display = getWindowManager().getDefaultDisplay();
Point size = getDisplaySize(display);
int targetW = size.x;
// Get the dimensions of the bitmap
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(imageLocation, bmOptions);
int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;
// Determine how much to scale down the image
int scaleFactor = Math.min(photoW / targetW, photoH / targetW);
// Decode the image file into a Bitmap sized to fill the View
bmOptions.inJustDecodeBounds = false;
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;
Bitmap bitmap = BitmapFactory.decodeFile(imageLocation, bmOptions);
int rotationForImage = getRotationForImage(imageLocation);
if (rotationForImage != 0) {
int targetWidth = rotationForImage == 90 || rotationForImage == 270 ? bitmap.getHeight() : bitmap.getWidth();
int targetHeight = rotationForImage == 90 || rotationForImage == 270 ? bitmap.getWidth() : bitmap.getHeight();
Bitmap rotatedBitmap = Bitmap.createBitmap(targetWidth, targetHeight, bitmap.getConfig());
Canvas canvas = new Canvas(rotatedBitmap);
Matrix matrix = new Matrix();
matrix.setRotate(rotationForImage, bitmap.getWidth() / 2, bitmap.getHeight() / 2);
canvas.drawBitmap(bitmap, matrix, new Paint());
bitmap.recycle();
bitmap = rotatedBitmap;
}
Bitmap resized;
if(bitmap.getWidth() >= 900 || bitmap.getHeight() >=900)
{
int newWidth = Math.round(bitmap.getWidth()/2);
int newHeight = Math.round(bitmap.getHeight()/2);
resized = Bitmap.createScaledBitmap(bitmap, newWidth, newHeight, true);
}
else
{
resized = bitmap;
}
//bitmap.recycle();
bitmap = resized;
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 70, bytes);
try
{
File f = new File(imageLocation);
f.createNewFile();
//write the bytes in file
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
fo.close();
}
catch(java.io.IOException e){}
imageView.setImageBitmap(bitmap);
}
您可以在该方法的顶部看到从相机意图保存的图像文件的静态路径。
我想调整大小、旋转方法可能会导致崩溃，但我不明白为什么会这样，这对我来说都是非常标准的 java 编码。
任何人都可以看到我在这里所做的事情有什么明显的错误吗？正如我在这个线程的标题中所说，我的代码导致大约 20% 的运行它的设备崩溃，这是不可接受的。我可以处理 5% 但不能处理 20%。
我意识到 android 开发在这方面有点像一场噩梦，因为你必须考虑这么多不同的设备类型（制造商、android 版本等），但我认为相机活动应该比这更好地标准化。正如我在该线程顶部所说的那样，我已经对这个问题进行了很多研究，并且看到几个人遇到了与我类似的问题，但没有涵盖大多数设备的良好解决方案。我真的不想从零开始写（我也不认为我应该写）我自己的相机。Android设备上必须有一个更好的默认内置摄像头意图实现......我只是还没有找到它。如您所见，我什至不关心动态创建图像，这应该会使这个项目变得更容易。
TIA
编辑：根据下面的评论，我添加了来自故障相机的堆栈跟踪。它看起来像一个空指针异常。我拍了大约 6 张照片，然后继续使用调用相机意图的按钮返回，直到最终失败。这是堆栈跟踪：
STACK_TRACE
"java.lang.RuntimeException: Unable to resume activity {com.myapp/com.myapp.MyActivity}: java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=904, result=-1, data=null} to activity {com.myapp/com.myapp.MyActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2124)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2139)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1672)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:2836)
at android.app.ActivityThread.access$1600(ActivityThread.java:117)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3687)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=904, result=-1, data=null} to activity {com.myapp/com.myapp.MyActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:2536)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2111)
... 13 more
Caused by: java.lang.NullPointerException
at com.myapp.MyActivity.onActivityResult(EnterContest.java:257)
at android.app.Activity.dispatchActivityResult(Activity.java:3908)
at android.app.ActivityThread.deliverResults(ActivityThread.java:2532)
... 14 more
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=904, result=-1, data=null} to activity {com.myapp/com.myapp.MyActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:2536)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2111)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2139)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1672)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:2836)
at android.app.ActivityThread.access$1600(ActivityThread.java:117)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3687)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.myapp.MyActivity.onActivityResult(EnterContest.java:257)
at android.app.Activity.dispatchActivityResult(Activity.java:3908)
at android.app.ActivityThread.deliverResults(ActivityThread.java:2532)
... 14 more
java.lang.NullPointerException
at com.myapp.MyActivity.onActivityResult(EnterContest.java:257)
at android.app.Activity.dispatchActivityResult(Activity.java:3908)
at android.app.ActivityThread.deliverResults(ActivityThread.java:2532)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2111)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2139)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1672)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:2836)
at android.app.ActivityThread.access$1600(ActivityThread.java:117)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3687)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)