我正在开发一个应用程序，其中有一个按钮，用于从图库中选择图像或从相机捕获图像。当我从图库中选择一个图像时，没有错误图像最终显示正常，但是当我从相机应用程序中捕获图像时崩溃。
以下是错误：
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=66, result=-1, data=null} to activity
{com.byteshaft.prospectform/com.byteshaft.prospectform.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.net.Uri android.content.Intent.getData()' on a null object reference
at android.app.ActivityThread.deliverResults(ActivityThread.java:4297)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:4347)
at android.app.ActivityThread.-wrap20(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1557)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:173)
at android.app.ActivityThread.main(ActivityThread.java:6459)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:938)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:828)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.net.Uri android.content.Intent.getData()' on a null object reference
at com.byteshaft.prospectform.MainActivity.onActivityResult(MainActivity.java:400)
at android.app.Activity.dispatchActivityResult(Activity.java:6926)
at android.app.ActivityThread.deliverResults(ActivityThread.java:4293)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:4347)
at android.app.ActivityThread.-wrap20(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1557)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:173)
at android.app.ActivityThread.main(ActivityThread.java:6459)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:938)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:828)
我从图库/相机中挑选图片的代码：
public void openImageIntent() {
File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String fname = "Prospect-form" + timeStamp;
final File sdImageMainDirectory = new File(storageDir, fname);
outputFileUri = Uri.fromFile(sdImageMainDirectory);
// Camera.
final List<Intent> cameraIntents = new ArrayList<>();
final Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
final PackageManager packageManager = getPackageManager();
final List<ResolveInfo> listCam = packageManager.queryIntentActivities(captureIntent, 0);
for(ResolveInfo res : listCam) {
final String packageName = res.activityInfo.packageName;
final Intent intent = new Intent(captureIntent);
intent.setComponent(new ComponentName(res.activityInfo.packageName, res.activityInfo.name));
intent.setPackage(packageName);
intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
cameraIntents.add(intent);
}
//Gallery.
Intent galleryIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
// Filesystem.
final Intent fsIntent = new Intent();
fsIntent.setType("*/*");
fsIntent.setAction(Intent.ACTION_GET_CONTENT);
cameraIntents.add(fsIntent);
//Create the Chooser
final Intent chooserIntent = Intent.createChooser(galleryIntent, "Select Source");
chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, cameraIntents.toArray(new Parcelable[cameraIntents.size()]));
startActivityForResult(chooserIntent, 66);
}
onActivityResult 代码：`
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(resultCode == Activity.RESULT_OK)
switch (requestCode){
case 5:
Uri selectedImage = data.getData();
try {
Bitmap bitmap = MediaStore.Images.Media.getBitmap(MainActivity.this.getContentResolver(), selectedImage);
Bitmap resizedBitMap;
resizedBitMap = Bitmap.createScaledBitmap(bitmap, 100, 100, true);
imageView.setImageBitmap(resizedBitMap);
System.out.println(Helpers.getPath(MainActivity.this, selectedImage));
imagePath = Helpers.getPath(MainActivity.this, selectedImage);
} catch (IOException e) {
Log.i("TAG", "Some exception " + e);
}
break;
}
}`
stackoverflow上有一些非常有用的答案，但我无法解决我的问题。当我从相机中选择捕获图像时，只有错误出现，否则当我从图库中选择图像时根本没有错误。
有什么建议吗？
答案 0 :(得分：1)
这是因为从相机和图库中选择图像不会返回相同的结果。您必须通过查看意图来检查用户选择了哪一个。你可以这样做：
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == mRequestCode) {
if (resultCode == Activity.RESULT_OK) {
boolean isCamera = true;
if (data != null && data.getData() != null) {
String action = data.getAction();
isCamera = MediaStore.ACTION_IMAGE_CAPTURE.equals(action);
}
try {
Uri uriFileSrc = isCamera ? mOutputFileUri : data.getData();
//Do what do you need with the Uri
} catch (Exception ex) {
Toast.makeText(mActivity, R.string.error_creating_file, Toast.LENGTH_SHORT).show();
}
}
}
}