我有两个图像按钮，用于相机和图库。如果选择“相机”，则可以从相机拍摄照片，然后该照片必须显示在图像视图中的其他活动中。如果您选择“图库”，则必须从图库中选择一张照片，然后该照片必须在另一个活动中显示。我的画廊代码很好。我创建了另外两个活动（具有相同的布局），一个用于图库，另一个用于相机。但相机代码不起作用。这是我的代码： MainActivity：
private static final int REQUEST_CAMERA = 1;
private static int SELECT_FILE = 1;
ImageButton take_photo = (ImageButton) findViewById(R.id.cameraButton);
ImageButton get_photo = (ImageButton) findViewById(R.id.galleryButton);
if (take_photo != null) {
take_photo.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_CAMERA);
}
});
}
//to get the photo from gallery
if (get_photo != null) {
get_photo.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, SELECT_FILE);
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == SELECT_FILE) {
selectedImageURI = data.getData();
File imageFile = new File(getRealPathFromURI(selectedImageURI));
Intent intent = new Intent(this, ShowPhotoActivity.class);
intent.putExtra("imagePath", imageFile.toString());
startActivity(intent);
} else {
if (requestCode == REQUEST_CAMERA) {
{
try {
Uri returnUri = data.getData();
Bitmap bitmapImage = MediaStore.Images.Media.getBitmap(MainActivity.this.getContentResolver(), returnUri);
Intent i = new Intent(this, ShowCameraPhotoActivity.class);
i.putExtra("image", bitmapImage);
startActivity(i);
} catch (IOException e) {
e.printStackTrace();
} }
}}
} }
private String getRealPathFromURI(Uri contentURI) {
String result;
Cursor cursor = getContentResolver().query(contentURI, null, null, null, null);
if (cursor == null) {
result = contentURI.getPath();
} else {
cursor.moveToFirst();
int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
result = cursor.getString(idx);
cursor.close();
}
return result;
}
ShowPhotoActivity（这是图库的活动）：
Bundle extras = getIntent().getExtras();
Uri uri = Uri.parse(extras.getString("imagePath"));
if (showPhoto != null) {
Bitmap bm = BitmapFactory.decodeFile(uri.getPath());
showPhoto.setImageBitmap(bm); }
ShowCameraPhotoActivity（这是相机的活动）：
Bitmap bitmap = (Bitmap) this.getIntent().getParcelableExtra("image");
if (showPhoto != null) {
showPhoto.setImageBitmap(bitmap);
}
的manifest.xml：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.CAMERA" />
我尝试过另外一项活动，但这也没有用。在logcat中，它说它发生的原因是getRealPathFromUri（）。但我不知道是什么。如果您有任何解决方案或更好的想法，请帮助我：）
logcat的：
Process: com.example.gentaliu.photoeditor, PID: 22360
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { act=inline-data (has extras) }} to activity {com.example.gentaliu.photoeditor/com.example.gentaliu.photoeditor.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference
at android.app.ActivityThread.deliverResults(ActivityThread.java:3840)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3883)
at android.app.ActivityThread.access$1700(ActivityThread.java:165)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1426)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5593)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference
at android.content.ContentResolver.acquireUnstableProvider(ContentResolver.java:1477)
at android.content.ContentResolver.query(ContentResolver.java:473)
at android.content.ContentResolver.query(ContentResolver.java:426)
at com.example.gentaliu.photoeditor.MainActivity.getRealPathFromURI(MainActivity.java:189)
at com.example.gentaliu.photoeditor.MainActivity.onActivityResult(MainActivity.java:105)
at android.app.Activity.dispatchActivityResult(Activity.java:6320)
at android.app.ActivityThread.deliverResults(ActivityThread.java:3836)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3883)
at android.app.ActivityThread.access$1700(ActivityThread.java:165)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1426)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5593)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
09-21 19:11:44.293 22360-22360/com.example.gentaliu.photoeditor I/Process: Sending signal. PID: 22360 SIG: 9
答案 0 :(得分：1)
您的代码存在一些问题，包括：
getRealPathFromURI()一般来说不可靠，在这种情况下是不必要的。将Uri本身传递给ShowPhotoActivity。
ShowPhotoActivity正在主应用程序线程上加载图像。不要这样做。请使用众多image loading libraries available for Android中的一个，因为他们可以使用Uri异步加载您的图片。就个人而言，我使用毕加索。
您假设从[{1}}返回Uri。这不是ACTION_IMAGE_CAPTURE的工作方式。
相反，替换：
ACTION_IMAGE_CAPTURE使用：
Uri returnUri = data.getData();
Bitmap bitmapImage = MediaStore.Images.Media.getBitmap(MainActivity.this.getContentResolver(), returnUri);