onCreate 中的引用集在 onActivityResult 中为 null
Reference set in onCreate is null in onActivityResult
我有 activity 我添加了对象（自定义对象）并在 oncreate 中初始化它
方法：
company=new HR_Company();
在activity开头我是这样写的:
HR_Company company;
当我尝试在这个对象中设置一个名称时
company.setHr_company_location("dfdfd");
它 return 我是公司对象为空的异常，这是怎么回事？
我尝试在 onActivityResult 方法中设置
这是代码
public class HR_DescriptionActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {
public static final int CAMERA_REQUEST = 1;
public static final int GALLERY_REQUEST = 2;
HR_Company company;
EditText locationExitTxt;
EditText Company_name;
EditText desc;
TextView title;
ImageView viewImage;
Button up;
Button addPos;
Button save_hr_description;
ArrayList<Position> positions;
GoogleApiClient mGoogleApiClient;
GpsManger gps;
Bitmap cameraresized;
byte[] buffer=null;
ImageManager manager;
String[] permissions = new String[]{Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION};
private ImageView imgphoto;
@Override
protected void onCreate(Bundle savedInstanceState) {
gps=new GpsManger(HR_DescriptionActivity.this,mGoogleApiClient);
super.onCreate(savedInstanceState);
company=new HR_Company();
setContentView(R.layout.activity_hr__description);
//================== get views ===============
Toolbar toolbar = (Toolbar) findViewById(R.id.hr_toolbar);
imgphoto = (ImageView) findViewById(R.id.viewImage);
viewImage=(ImageView)findViewById(R.id.viewImage);
locationExitTxt = (EditText) findViewById(R.id.gps_company_location);
Company_name=(EditText)findViewById(R.id.Company_name);
desc=(EditText) findViewById(R.id.hr_description_desc);
title=(TextView)findViewById(R.id.toolbar_title);
addPos=(Button)findViewById(R.id.hr_add_position);
save_hr_description=(Button)findViewById(R.id.save_hr_description);
up = (Button) findViewById(R.id.upload);
manager=new ImageManager(HR_DescriptionActivity.this,viewImage,company,Company_name,desc,locationExitTxt);
//============================================
//================== toolbar configuration ===============
setSupportActionBar(toolbar);
getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_clear_white_24dp);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowTitleEnabled(false);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
title.setText("Description");
//============================================
//================== keyboard events ===============
locationExitTxt.addTextChangedListener(passwordWatcher);
desc.addTextChangedListener(passwordWatcherfor3lines);
Company_name.addTextChangedListener(passwordWatcher);
if(ContextCompat.checkSelfPermission(HR_DescriptionActivity.this,Manifest.permission.CAMERA)!=PackageManager.PERMISSION_GRANTED)
{
ActivityCompat.requestPermissions(HR_DescriptionActivity.this,new String[]{Manifest.permission.CAMERA},0);
}
if (gps.hasPermission()) {
gps.ConnectToGPS();
}
else
{
gps.requestPerms();
}
Company_name.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
if(hasFocus)
{
if (gps.hasPermission()) {
gps.ConnectToGPS();
}
else
{
gps.requestPerms();
}
}
if(!hasFocus)
{
gps.ConnectToGPS();
locationExitTxt.setText(gps.getCity());
}
}
});
locationExitTxt.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
locationExitTxt.setText(gps.getCity());
}
});
addPos.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
company=new HR_Company();
company.setHr_company(Company_name.getText().toString());
company.setHr_company_description(desc.getText().toString());
company.setHr_company_location(desc.getText().toString());
company.setHr_company_location(locationExitTxt.getText().toString());
manager.LoadCompanyData(company);
Intent i = new Intent(HR_DescriptionActivity.this, HR_Position_Activity.class);
i.putExtra("HR_Company", company);
startActivity(i);
overridePendingTransition(R.anim.slide_in, R.anim.slide_out);
}
});
save_hr_description.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
}
});
up.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
selectImage();
}
});
Intent i= getIntent();
company= (HR_Company)i.getSerializableExtra("HR_Company");
if(company!=null)
{
manager.LoadCompanyData(company);
}
}
private final TextWatcher passwordWatcher = new TextWatcher() {
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(s.toString().substring(start).contains("\n"))
{
View view=getCurrentFocus();
InputMethodManager imm=(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(),0);
}
}
public void afterTextChanged(Editable s) {
}
};
private final TextWatcher passwordWatcherfor3lines = new TextWatcher() {
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(s.toString().substring(start).contains("\n")&& desc.getLineCount()>3)
{
View view=getCurrentFocus();
InputMethodManager imm=(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(),0);
}
}
public void afterTextChanged(Editable s) {
}
};
private void selectImage() {
final CharSequence[] options = { "Take Photo", "Choose from Gallery","Cancel" };
AlertDialog.Builder builder = new AlertDialog.Builder(HR_DescriptionActivity.this);
builder.setTitle("Add Photo!");
builder.setItems(options, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int item) {
if (options[item].equals("Take Photo"))
{
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, CAMERA_REQUEST);
}
else if (options[item].equals("Choose from Gallery"))
{
Intent intent = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, GALLERY_REQUEST);
}
else if (options[item].equals("Cancel")) {
dialog.dismiss();
}
}
});
builder.show();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == CAMERA_REQUEST) {
cameraresized=(Bitmap) data.getExtras().get("data");
String path= manager.saveToInternalStorage(cameraresized,getApplicationContext());
File f=new File(path, "logo_image.jpg");
InputStream is=null;
try {
is = new FileInputStream(f);
buffer=manager.readBytes(is);
company.setLogo(buffer);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Glide.with(this).load(company.getLogo()).skipMemoryCache(true).diskCacheStrategy(DiskCacheStrategy.NONE).into(imgphoto);
} else if (requestCode == GALLERY_REQUEST) {
Uri uri = data.getData();
InputStream inputStream;
try {
inputStream=getContentResolver().openInputStream(uri);
Bitmap bit = BitmapFactory.decodeStream(inputStream);
imgphoto.setImageBitmap(bit);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
}
// =================== back activity event ================
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
// ========================================================
@Override
public void onConnected(@Nullable Bundle bundle) {}
@Override
public void onConnectionSuspended(int i) {}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {}
}
异常发生在
company.setLogo(buffer);
问题最有可能出现在
company= (HR_Company)i.getSerializableExtra("HR_Company");
检查 Intent 是否有额外的，否则你正在将 null 设置为引用。
if(i.hasExtra("HR_Company"))
company= (HR_Company)i.getSerializableExtra("HR_Company")
else
company = new HR_Company();
请注意，您的代码未遵循命名和格式约定
我有 activity 我添加了对象（自定义对象）并在 oncreate 中初始化它 方法：
company=new HR_Company();
在activity开头我是这样写的:
HR_Company company;
当我尝试在这个对象中设置一个名称时
company.setHr_company_location("dfdfd");
它 return 我是公司对象为空的异常，这是怎么回事？ 我尝试在 onActivityResult 方法中设置 这是代码
public class HR_DescriptionActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {
public static final int CAMERA_REQUEST = 1;
public static final int GALLERY_REQUEST = 2;
HR_Company company;
EditText locationExitTxt;
EditText Company_name;
EditText desc;
TextView title;
ImageView viewImage;
Button up;
Button addPos;
Button save_hr_description;
ArrayList<Position> positions;
GoogleApiClient mGoogleApiClient;
GpsManger gps;
Bitmap cameraresized;
byte[] buffer=null;
ImageManager manager;
String[] permissions = new String[]{Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION};
private ImageView imgphoto;
@Override
protected void onCreate(Bundle savedInstanceState) {
gps=new GpsManger(HR_DescriptionActivity.this,mGoogleApiClient);
super.onCreate(savedInstanceState);
company=new HR_Company();
setContentView(R.layout.activity_hr__description);
//================== get views ===============
Toolbar toolbar = (Toolbar) findViewById(R.id.hr_toolbar);
imgphoto = (ImageView) findViewById(R.id.viewImage);
viewImage=(ImageView)findViewById(R.id.viewImage);
locationExitTxt = (EditText) findViewById(R.id.gps_company_location);
Company_name=(EditText)findViewById(R.id.Company_name);
desc=(EditText) findViewById(R.id.hr_description_desc);
title=(TextView)findViewById(R.id.toolbar_title);
addPos=(Button)findViewById(R.id.hr_add_position);
save_hr_description=(Button)findViewById(R.id.save_hr_description);
up = (Button) findViewById(R.id.upload);
manager=new ImageManager(HR_DescriptionActivity.this,viewImage,company,Company_name,desc,locationExitTxt);
//============================================
//================== toolbar configuration ===============
setSupportActionBar(toolbar);
getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_clear_white_24dp);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowTitleEnabled(false);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
title.setText("Description");
//============================================
//================== keyboard events ===============
locationExitTxt.addTextChangedListener(passwordWatcher);
desc.addTextChangedListener(passwordWatcherfor3lines);
Company_name.addTextChangedListener(passwordWatcher);
if(ContextCompat.checkSelfPermission(HR_DescriptionActivity.this,Manifest.permission.CAMERA)!=PackageManager.PERMISSION_GRANTED)
{
ActivityCompat.requestPermissions(HR_DescriptionActivity.this,new String[]{Manifest.permission.CAMERA},0);
}
if (gps.hasPermission()) {
gps.ConnectToGPS();
}
else
{
gps.requestPerms();
}
Company_name.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
if(hasFocus)
{
if (gps.hasPermission()) {
gps.ConnectToGPS();
}
else
{
gps.requestPerms();
}
}
if(!hasFocus)
{
gps.ConnectToGPS();
locationExitTxt.setText(gps.getCity());
}
}
});
locationExitTxt.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
locationExitTxt.setText(gps.getCity());
}
});
addPos.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
company=new HR_Company();
company.setHr_company(Company_name.getText().toString());
company.setHr_company_description(desc.getText().toString());
company.setHr_company_location(desc.getText().toString());
company.setHr_company_location(locationExitTxt.getText().toString());
manager.LoadCompanyData(company);
Intent i = new Intent(HR_DescriptionActivity.this, HR_Position_Activity.class);
i.putExtra("HR_Company", company);
startActivity(i);
overridePendingTransition(R.anim.slide_in, R.anim.slide_out);
}
});
save_hr_description.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
}
});
up.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
selectImage();
}
});
Intent i= getIntent();
company= (HR_Company)i.getSerializableExtra("HR_Company");
if(company!=null)
{
manager.LoadCompanyData(company);
}
}
private final TextWatcher passwordWatcher = new TextWatcher() {
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(s.toString().substring(start).contains("\n"))
{
View view=getCurrentFocus();
InputMethodManager imm=(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(),0);
}
}
public void afterTextChanged(Editable s) {
}
};
private final TextWatcher passwordWatcherfor3lines = new TextWatcher() {
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(s.toString().substring(start).contains("\n")&& desc.getLineCount()>3)
{
View view=getCurrentFocus();
InputMethodManager imm=(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(),0);
}
}
public void afterTextChanged(Editable s) {
}
};
private void selectImage() {
final CharSequence[] options = { "Take Photo", "Choose from Gallery","Cancel" };
AlertDialog.Builder builder = new AlertDialog.Builder(HR_DescriptionActivity.this);
builder.setTitle("Add Photo!");
builder.setItems(options, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int item) {
if (options[item].equals("Take Photo"))
{
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, CAMERA_REQUEST);
}
else if (options[item].equals("Choose from Gallery"))
{
Intent intent = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, GALLERY_REQUEST);
}
else if (options[item].equals("Cancel")) {
dialog.dismiss();
}
}
});
builder.show();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == CAMERA_REQUEST) {
cameraresized=(Bitmap) data.getExtras().get("data");
String path= manager.saveToInternalStorage(cameraresized,getApplicationContext());
File f=new File(path, "logo_image.jpg");
InputStream is=null;
try {
is = new FileInputStream(f);
buffer=manager.readBytes(is);
company.setLogo(buffer);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Glide.with(this).load(company.getLogo()).skipMemoryCache(true).diskCacheStrategy(DiskCacheStrategy.NONE).into(imgphoto);
} else if (requestCode == GALLERY_REQUEST) {
Uri uri = data.getData();
InputStream inputStream;
try {
inputStream=getContentResolver().openInputStream(uri);
Bitmap bit = BitmapFactory.decodeStream(inputStream);
imgphoto.setImageBitmap(bit);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
}
// =================== back activity event ================
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
// ========================================================
@Override
public void onConnected(@Nullable Bundle bundle) {}
@Override
public void onConnectionSuspended(int i) {}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {}
}
异常发生在
company.setLogo(buffer);
问题最有可能出现在
company= (HR_Company)i.getSerializableExtra("HR_Company");
检查 Intent 是否有额外的，否则你正在将 null 设置为引用。
if(i.hasExtra("HR_Company"))
company= (HR_Company)i.getSerializableExtra("HR_Company")
else
company = new HR_Company();
请注意，您的代码未遵循命名和格式约定