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我一直在嘗試捕獲圖像並調整其大小（以顯示它）並存儲其base64值。BitmapFactory.decodeFile在某些設備上返回null
private String setImageAndReturnBase64String(ImageView imageView) {
Bitmap bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath);
bitmap = Bitmap.createScaledBitmap(bitmap, 400, 400, false);
imageView.setImageBitmap(bitmap);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 40, byteArrayOutputStream);
byte[] byteArray = byteArrayOutputStream.toByteArray();
return Base64.encodeToString(byteArray, Base64.DEFAULT);
}
哪裏mCurrentPhotoPath是
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPG_" + timeStamp + "_";
File image = File.createTempFile(
imageFileName, /* prefix */
".jpg", /* suffix */
storageDir /* directory */
);
mCurrentPhotoPath = image.getAbsolutePath();
和storageDir是
File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
if (!(storageDir != null && storageDir.exists())) {
if (storageDir != null) {
storageDir.mkdir();
}
}
所有必要的權限，並在清單的文件提供者。
但在某些設備BitmapFactory.decodeFile(mCurrentPhotoPath);返回null導致運行時異常。從火力地堡
堆棧跟蹤：
android.app.ActivityThread.handleResumeActivity (ActivityThread.java:3152)
android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2495)
android.app.ActivityThread.-wrap11 (ActivityThread.java)
android.app.ActivityThread$H.handleMessage (ActivityThread.java:1354)
android.os.Handler.dispatchMessage (Handler.java:102)
android.os.Looper.loop (Looper.java:148)
android.app.ActivityThread.main (ActivityThread.java:5443)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:728)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:618)
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Caused by java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=2, result=-1, data=null} to activity {com.app.in/com.app.activities.JobCard}: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getWidth()' on a null object reference
android.app.ActivityThread.deliverResults (ActivityThread.java:3720)
android.app.ActivityThread.performResumeActivity (ActivityThread.java:3107)
android.app.ActivityThread.handleResumeActivity (ActivityThread.java:3152)
android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2495)
android.app.ActivityThread.-wrap11 (ActivityThread.java)
android.app.ActivityThread$H.handleMessage (ActivityThread.java:1354)
android.os.Handler.dispatchMessage (Handler.java:102)
android.os.Looper.loop (Looper.java:148)
android.app.ActivityThread.main (ActivityThread.java:5443)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:728)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:618)
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Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getWidth()' on a null object reference
android.graphics.Bitmap.createScaledBitmap (Bitmap.java:636))
android.app.Activity.dispatchActivityResult (Activity.java:6442)
android.app.ActivityThread.deliverResults (ActivityThread.java:3716)
android.app.ActivityThread.performResumeActivity (ActivityThread.java:3107)
android.app.ActivityThread.handleResumeActivity (ActivityThread.java:3152)
android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2495)
android.app.ActivityThread.-wrap11 (ActivityThread.java)
android.app.ActivityThread$H.handleMessage (ActivityThread.java:1354)
android.os.Handler.dispatchMessage (Handler.java:102)
android.os.Looper.loop (Looper.java:148)
android.app.ActivityThread.main (ActivityThread.java:5443)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:728)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:618)
如何防止這種運行時異常情況發生在某些設備上？
編輯：在實施評論中建議的方法後，這是我一直面臨的。
Exception java.lang.RuntimeException: Unable to resume activity {com.app.in/com.app.activities.Detailed}: java.lang.RuntimeException: Failure delivering result ResultInfo{who=android:fragment:0, request=0, result=-1, data=null} to activity {com.app.in/com.app.activities.Detailed}: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference
android.app.ActivityThread.performResumeActivity (ActivityThread.java:3121)
android.app.ActivityThread.handleResumeActivity (ActivityThread.java:3152)
android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2495)
android.app.ActivityThread.-wrap11 (ActivityThread.java)
android.app.ActivityThread$H.handleMessage (ActivityThread.java:1354)
android.os.Handler.dispatchMessage (Handler.java:102)
android.os.Looper.loop (Looper.java:148)
android.app.ActivityThread.main (ActivityThread.java:5443)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:728)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:618)
Caused by java.lang.RuntimeException: Failure delivering result ResultInfo{who=android:fragment:0, request=0, result=-1, data=null} to activity {com.app.in/com.app.activities.Detailed}: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference
android.app.ActivityThread.deliverResults (ActivityThread.java:3720)
android.app.ActivityThread.performResumeActivity (ActivityThread.java:3107)
android.app.ActivityThread.handleResumeActivity (ActivityThread.java:3152)
android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2495)
android.app.ActivityThread.-wrap11 (ActivityThread.java)
android.app.ActivityThread$H.handleMessage (ActivityThread.java:1354)
android.os.Handler.dispatchMessage (Handler.java:102)
android.os.Looper.loop (Looper.java:148)
android.app.ActivityThread.main (ActivityThread.java:5443)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:728)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:618)
Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference
com.app.fragments.ModeDetailsFragment.setImageAndReturnBase64String (ModeDetailsFragment.java:224)
com.app.fragments.ModeDetailsFragment.onActivityResult (ModeDetailsFragment.java:198)
android.app.Activity.dispatchActivityResult (Activity.java:6466)
android.app.ActivityThread.deliverResults (ActivityThread.java:3716)
android.app.ActivityThread.performResumeActivity (ActivityThread.java:3107)
android.app.ActivityThread.handleResumeActivity (ActivityThread.java:3152)
android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2495)
android.app.ActivityThread.-wrap11 (ActivityThread.java)
android.app.ActivityThread$H.handleMessage (ActivityThread.java:1354)
android.os.Handler.dispatchMessage (Handler.java:102)
android.os.Looper.loop (Looper.java:148)
android.app.ActivityThread.main (ActivityThread.java:5443)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:728)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:618)
改進方法
private String setImageAndReturnBase64String(ImageView imageView) {
Bitmap bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath);
if(bitmap == null) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(mCurrentPhotoPath, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, 400, 400);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath, options);
} else {
bitmap = Bitmap.createScaledBitmap(bitmap, 400, 400, false);
}
imageView.setImageBitmap(bitmap);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 40, byteArrayOutputStream);
byte[] byteArray = byteArrayOutputStream.toByteArray();
return Base64.encodeToString(byteArray, Base64.DEFAULT);
}
private int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height/2;
final int halfWidth = width/2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight/inSampleSize) >= reqHeight
&& (halfWidth/inSampleSize) >= reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
我的猜測是您的堆空間不足。而不是在整個圖像中讀取，然後縮小它，使用'BitmapFactory.Options'和'inSampleSize'來讀取一個縮小的圖像，並使用較少的內存。 – CommonsWare
VM免費：7.21MB VM總：19.58MB VM最大：96MB 電池電量：71％ 製造商：LG電子 型號：LG-K420 局：Msm8916 Android的API：22 Android操作系統5.1.1 品牌：Lge 內存：1.86GB 這是崩潰期間的設備數據。 –
@CommonsWare你可以看看這個問題嗎？ –