It doesn't show any error but when i run it on my phone the app crashes everytime!
`PizzaType.java
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pizzatype);
RadioButton rButton = (RadioButton) findViewById(R.id.radioButton);
String rText = rButton.getText().toString();
Intent intent = new Intent(Pizzatype.this, Overview.class);
intent.putExtra("Bbread","Brown Bread");
startActivity(intent);
String data = getIntent().getExtras().getString("Bbread");
}
Overview.java
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_overview);
String value= getIntent().getStringExtra("Bbread");
Intent intent = new Intent(this, Pizzatype.class);
intent.putExtra("Bbread", value);
startActivity(intent);
String data= getIntent().getStringExtra("Bbread");
}
Try cleaning and re-running your project. Some times the R.java file get corrupted. and it leads to null pointer exceptions.
Related
I have researched many problems like mine on the internet and none seem to be doing what I'm trying to do. What I am trying to do is get a textview that is currently blank in my high_risk.xml file, and make it have text based on if a button is clicked in another class. Here is what I have so far...
Question13Activity(if the yes button is clicked I want to be able to set the text in the HighRisk Activity)
yes = (Button) findViewById(R.id.finalYes);
yes.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
Intent intent = getIntent();
String text = intent.getStringExtra("New Text");
t = (TextView) findViewById(R.id.abusedOrNah);
t.setText(text);
Intent myIntent = new Intent(v.getContext(), Question13Activity.class);
startActivity(myIntent);
}
});
This is how I have the static variable t defined in my highrisk activity class...
HighRiskActivity(this is where I want the text to be set and displayed)
public static TextView t;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.high_risk);
Intent myIntent = new Intent(HighRiskActivity.this, Question12Activity.class);
myIntent.putExtra("Text", "New Text");
startActivity(myIntent);
Every time I try and access the contents of t in another class and change it's text, it always returns null. Any way I can fix this from happening? Any help would be greatly appreciated :)
You can use Bounds, to get the the data to the new Activity and set the text from there:
Intent myIntent = new Intent(v.getContext(), Question13Activity.class);
myIntent.putExtra("<KEY-NAME>", "<TEXT>");
startActivity(myIntent);
And in the Question13Activity.class:
Intent intent = getIntent();
String text= intent.getStringExtra("<KEY-NAME>");
t = (TextView) findViewById(R.id.abusedOrNah);
t.setText(text);
UPDATE:
Use it so:
HighRiskActivity.class:
yes = (Button) findViewById(R.id.finalYes);
yes.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
Intent myIntent = new Intent(v.getContext(), Question13Activity.class);
myIntent.putExtra("TestKey", "My new Text");
startActivity(myIntent);
}
});
Question13Activity.class:
TextView t;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.high_risk);
Intent intent = getIntent();
String text= intent.getStringExtra("TestKey");
t = (TextView) findViewById(R.id.abusedOrNah);
t.setText(text);
In order to setText() from another class (for example, from your Custom class), you need to specify the activity on which you'd like to do that.
Unless a class does have a reference of your context, you cannot call 'findViewById()'
To do that, you use Context as a parameter for custom class constructor.
Just after you have set the context will you be able to call
TextView txtView = (TextView) ((Activity)context).findViewById(R.id.text);
txtView.setText("foo");
}
I have two activities that I would like to send data between. I would like to send two strings from the second activity to the first, where the strings will be manipulated and applied to the code. Here is the intent I have in the second activity to send the strings to the first activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
phoneNum = (EditText)findViewById(R.id.phoneNum);
msgCounter = (EditText)findViewById(R.id.msgCount);
apply = (Button)findViewById(R.id.butto);
save = (Button)findViewById(R.id.butt);
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent pass = new Intent();
pass.putExtra("value", phoneNum.getText().toString());
pass.putExtra("cost",msgCounter.getText().toString());
startActivity(pass);
}
});
And here is the intent I have in the first acitivity to receive the data:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_text_messages);
request_code = 1;
FloatingActionButton button = (FloatingActionButton) findViewById(R.id.but);
assert button != null;
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(TextMessages.this,Settings.class);
startActivityForResult(intent, request_code);
Intent a = new Intent(TextMessages.this,Settings.class);
startActivityForResult(a, recode);
}
});
Intent pass = getIntent();
String address = pass.getStringExtra("value");
String string2 = pass.getStringExtra("cost");
However, the app always crashes when I start it. So I can not use any of the data. Thanks in advance to any help I may receive.
In the first activity you should get your strings from onActivityResult. You shouldn't use startActivity in second activity.
Checkout this link for more information
https://developer.android.com/training/basics/intents/result.html
In your second activity you should use setResult method.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
phoneNum = (EditText)findViewById(R.id.phoneNum);
msgCounter = (EditText)findViewById(R.id.msgCount);
apply = (Button)findViewById(R.id.butto);
save = (Button)findViewById(R.id.butt);
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent pass = new Intent();
pass.putExtra("value", phoneNum.getText().toString());
pass.putExtra("cost",msgCounter.getText().toString());
setResult(Activity.RESULT_OK,pass);
finish();
}
});
In your first activity you should get Intent data inside the onActivityResult method.
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == request_code) {
if(resultCode == Activity.RESULT_OK){
String value=data.getStringExtra("value");
String cost=data.getStringExtra("cost");
//handle value and cost.
}
}
}
I think it's because you missed out to put the target Activity class when you instantiate your intent. It should be like this:
Intent pass = new Intent(TargetActivity.class);
pass.putExtra("value", phoneNum.getText().toString());
pass.putExtra("cost",msgCounter.getText().toString());
startActivity(pass);
Hope it helps.
EDIT: But I agree with Abdullah. Since the first activity started the second activity, use onActivityResult to pass values to the first activity.
My guess is, the app starts into the second code block you posted. There is no value for String address = pass.getStringExtra("value"); or String string2 = pass.getStringExtra("cost"); when you start your app - only when the second activity sends these to the first activity. I would recommend finding a way to determine if its the second activity creating the first activity or creating a method to set these values in the first activity and call it in the second activity. Also, your second activity should be:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
phoneNum = (EditText)findViewById(R.id.phoneNum);
msgCounter = (EditText)findViewById(R.id.msgCount);
apply = (Button)findViewById(R.id.butto);
save = (Button)findViewById(R.id.butt);
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent pass = new Intent(SecondActivity.this, FirstActivity.class);
pass.putExtra("value", phoneNum.getText().toString());
pass.putExtra("cost",msgCounter.getText().toString());
startActivity(pass);
}
});
Below are two Activities:
Test_Result.java
Intent intent = new Intent();
intent.putExtra("flag","data");
intent.setClass(Test_Result.this, MainActivity.class);
startActivity(intent);
MainActivity.java
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
mainPager=(MyViewPager) findViewById(R.id.vPager);
radioGroup=(RadioGroup) findViewById(R.id.bottom_bar);
radioGroup.setOnCheckedChangeListener(this);
Intent intent = getIntent();
flag = intent.getStringExtra("flag");
if (flag == null){
initViews();
radioGroup.getChildAt(2).performClick();
}
else {
if (flag.equals("test")) {
initViews();
radioGroup.getChildAt(0).performClick();
}
if (flag.equals("data")) {
initViews();
radioGroup.getChildAt(1).performClick();
}
if (flag.equals("info")) {
initViews();
radioGroup.getChildAt(2).performClick();
}
}
}
private void initViews(){
fm=getSupportFragmentManager();
fragments=new ArrayList<Fragment>();
testFragment=TestFragment.getInstance();
dataFragment= DataFragment.getInstance();
informationFragment=InformationFragment.getInstance();
fragments.add(testFragment);
fragments.add(dataFragment);
fragments.add(informationFragment);
mainPager.setAdapter(new MainPageAdpter(fm));
}
When it jumps,there is no view in 3 fragments except radioGroup.
But when I open the app, three fragments are there in MainActivity.
Why? I just began to learn Android two weeks ago and I am innocent, please help me.
i am new to Andriod and programming. i am trying to make a to do list app, which will contain a listView, Button(add) in the main layout. when i click add i want it to go to another activity which will contain a editText and a add button. when i click the add button i want to update the list in my main activity. Now i was able to get the information from the second activity but when i try to add it in my list it over writes it.
How can i update my list as soon as my main activity appears again.
Here's what i have so far :
MainActivity class :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
add = (Button) findViewById(R.id.bAdd);
list = (ListView) findViewById(R.id.lvList);
addItems(); // i think this is the error but i dont know how to fix it.
alList = new ArrayList<String>();
aaList = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, alList);
list.setAdapter(aaList);
}
public void clickAdd(View v) { //when clicking the add button(add)
Intent intent = new Intent(MainActivity.this, AddItem.class);
startActivity(intent);
}
private void addItems(){
String s = getIntent().getStringExtra("item");
aaList.add(s);
aaList.notifyDataSetChanged();
}
AddItem class :
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.add_layout);
et = (EditText) findViewById(R.id.etAdd);
bt = (Button) findViewById(R.id.badd);
}
public void add(View v){ //when clicking the add button(bt)
edit = et.getText().toString();
Intent intent = new Intent(AddItem.this, MainActivity.class);
intent.putExtra("item", edit);
startActivity(intent);
}
Can you please tell me where and why i am going wrong? Thank You
First of all, you should use startACtivityForResult
Intent i = new Intent(this, SecondActivity.class);
startActivityForResult(i, 1);
Then in your second Activity
Intent returnIntent = new Intent();
returnIntent.putExtra("result",result);
setResult(RESULT_OK,returnIntent);
finish();
And back in your fist one:
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) {
if(resultCode == RESULT_OK){
String result=data.getStringExtra("result");
}
if (resultCode == RESULT_CANCELED) {
//Write your code if there's no result
}
}
}//onActivityResult
and then, your addItem should do the trick:
private void addItems(String s){
aaList.add(s);
aaList.notifyDataSetChanged();
}
I have this piece of code to start a new activity in my android test app
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btnpriv = (Button)findViewById(R.id.btn_priv);
btnpriv.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(), PrivateActivity.class);
startActivity(i);
}
});
This works as it should. At button press it changes to the new PrivateActivity. But it is a no-animation change. How can I make it f.x. slidein the new activity to have a nice transition?