Android，从图库中获取图像到 imageView
[英]Android, get image from gallery into a imageView
问题描述
I'm trying to add a photo from my gallery, round image with canvas and put intoa ImageView but I always get this error:
我正在尝试从我的画廊添加一张照片，用画布将图像圆形并放入 ImageView，但我总是收到此错误：
FATAL EXCEPTION: main Process: app.innova.cristobal.neton, PID: 8016 java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { dat=content://com.android.providers.media.documents/document/image:38 flg=0x1 }} to activity {app.innova.cristobal.neton/app.innova.cristobal.neton.Principal3Activity}: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getWidth()' on a null object reference at android.app.ActivityThread.deliverResults(ActivityThread.java:3699) at android.app.ActivityThread.handleSendResult(ActivityThread.java:3742) at android.app.ActivityThread.-wrap16(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1393) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.Zygote
This is my main code:这是我的主要代码：
myimageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select image"), 1);
}
});
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1 && resultCode == RESULT_OK) {
Uri selectedImageUri = data.getData();
imagepath = getPath(selectedImageUri);
Bitmap bitmap=BitmapFactory.decodeFile(imagepath);
ByteArrayOutputStream bytearrayoutputstream = new ByteArrayOutputStream();
//Resized image
Bitmap resizedBitmap = Bitmap.createScaledBitmap(bitmap, 150, 150, true);
resizedBitmap.compress(Bitmap.CompressFormat.JPEG,50,bytearrayoutputstream);
//Round image
int min = Math.min(resizedBitmap.getWidth(), resizedBitmap.getHeight());
Bitmap bitmapRounded = Bitmap.createBitmap(min, min, resizedBitmap.getConfig());
Canvas canvas = new Canvas(bitmapRounded);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setShader(new BitmapShader(resizedBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
canvas.drawRoundRect((new RectF(0.0f, 0.0f, min, min)), min / 2, min / 2, paint);
myimageView.setImageBitmap(bitmapRounded);
}
}
And in my Manifest file I have assigned these permissions:在我的清单文件中，我分配了这些权限：
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
But it always return me a null bitmap.但它总是返回一个空位图。
Some advice about what's wrong with my code?关于我的代码有什么问题的一些建议？
Thank you!谢谢！
2 个解决方案
解决方案1
1 已采纳 2019-05-02 07:57:35
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1 && resultCode == RESULT_OK) {
final Uri imageUri = data.getData();
final InputStream imageStream = getContentResolver().openInputStream(imageUri);
final Bitmap selectedImage = BitmapFactory.decodeStream(imageStream);
ByteArrayOutputStream bytearrayoutputstream = new ByteArrayOutputStream();
//Resized image
Bitmap resizedBitmap = Bitmap.createScaledBitmap(bitmap, 150, 150, true);
resizedBitmap.compress(Bitmap.CompressFormat.JPEG,50,bytearrayoutputstream);
//Round image
int min = Math.min(resizedBitmap.getWidth(), resizedBitmap.getHeight());
Bitmap bitmapRounded = Bitmap.createBitmap(min, min, resizedBitmap.getConfig());
Canvas canvas = new Canvas(bitmapRounded);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setShader(new BitmapShader(resizedBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
canvas.drawRoundRect((new RectF(0.0f, 0.0f, min, min)), min / 2, min / 2, paint);
myimageView.setImageBitmap(bitmapRounded);
} }
You need a content resolver to open an input stream to selected image URI.您需要一个内容解析器来打开选定图像 URI 的输入流。 Uri.getpath() returns an abstract path. Uri.getpath() 返回一个抽象路径。
解决方案2
0 2019-05-02 08:03:16
Add Permission "checkPermissionREAD_EXTERNAL_STORAGE"添加权限“checkPermissionREAD_EXTERNAL_STORAGE”
if (checkPermissionREAD_EXTERNAL_STORAGE(getContext())) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select File"),GET_PIC_CODE);
}
public boolean checkPermissionREAD_EXTERNAL_STORAGE(
final Context context) {
int currentAPIVersion = Build.VERSION.SDK_INT;
if (currentAPIVersion >= android.os.Build.VERSION_CODES.M) {
if (ContextCompat.checkSelfPermission(context,
Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(
(Activity) context,
Manifest.permission.READ_EXTERNAL_STORAGE)) {
showDialog("External storage", context,
Manifest.permission.READ_EXTERNAL_STORAGE);
} else {
ActivityCompat
.requestPermissions(
(Activity) context,
new String[] { Manifest.permission.READ_EXTERNAL_STORAGE },
MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
}
return false;
} else {
return true;
}
} else {
return true;
}
}
public void showDialog(final String msg, final Context context,
final String permission) {
AlertDialog.Builder alertBuilder = new AlertDialog.Builder(context);
alertBuilder.setCancelable(true);
alertBuilder.setTitle("Permission necessary");
alertBuilder.setMessage(msg + " permission is necessary");
alertBuilder.setPositiveButton(android.R.string.yes,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
ActivityCompat.requestPermissions((Activity) context,
new String[] { permission },
MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
}
});
AlertDialog alert = alertBuilder.create();
alert.show();
}
@Override
public void onRequestPermissionsResult(int requestCode,
String[] permissions, int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE:
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// do your stuff
} else {
Toast.makeText(getContext(), "GET_ACCOUNTS Denied",
Toast.LENGTH_SHORT).show();
}
break;
default:
super.onRequestPermissionsResult(requestCode, permissions,
grantResults);
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1 && resultCode == RESULT_OK) {
Uri selectedImageUri = data.getData();
imagepath = getPath(selectedImageUri);
Bitmap bitmap=BitmapFactory.decodeFile(imagepath);
ByteArrayOutputStream bytearrayoutputstream = new ByteArrayOutputStream();
//Resized image
Bitmap resizedBitmap = Bitmap.createScaledBitmap(bitmap, 150, 150, true);
resizedBitmap.compress(Bitmap.CompressFormat.JPEG,50,bytearrayoutputstream);
//Round image
int min = Math.min(resizedBitmap.getWidth(), resizedBitmap.getHeight());
Bitmap bitmapRounded = Bitmap.createBitmap(min, min, resizedBitmap.getConfig());
Canvas canvas = new Canvas(bitmapRounded);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setShader(new BitmapShader(resizedBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
canvas.drawRoundRect((new RectF(0.0f, 0.0f, min, min)), min / 2, min / 2, paint);
myimageView.setImageBitmap(bitmapRounded);
} } } }
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