I was wondering, how would I make a switch statement, that when that certain case was triggered, it would open a new screen with text. Would I use an intent? And if so, which one?
Thank you for your help in advance.
When you want to open a "new screen", you probably want to open a new activity. You would create a second Activity-derived class and use the following overload of the Intent constructor with startActivity:
Intent intent = new Intent(this, MySecondActivity.class);
startActivity(intent);
this will explicitly attempt to open a new Activity with the class name MySecondActivity
to pass a String of text from one Activity to another in this way, you can add it to the intent.
String someValue = "Some Value";
intent.putExtra("Some Key", someValue);
and in the code of your other Activity, you can get at this string via the Intent
getIntent().getStringExtra("Some Key");
Obviously you want to do null checks to make sure the key exists in the Intent, and you want to put a proper constant String somewhere instead of using a literal String for a key, but this is the basic gist.
Kriem... As Rich said you can launch a new activity using intents and push data to the new activity using extras. You can push data back to your main activity using startActivityForResult instead of startActivity. You can return to your main screen by calling finish() in the new screen. Finally, you can put the new screen event handlers into the NewScreen.java file.
The overall effect is a near full separation from dependency between the two activities, so that you might be able to easily re-use the NewScreen.java class in another project. I have some code here.
Related
I have an Online Ordering System from where users can complete the order in, at least, three steps. Each step below is a separate activity:
Make selection of a Plan
Select the Starting Date
Select Contents based on selected Plan in Step 1.
Now what I have done in step 1 is, once user clicks on a Plan and Order, below code runs onClick.
Intent intent = new Intent(context, SelectDate.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
Bundle extras = new Bundle();
extras.putString("pass_selected_meal_plan_id",mp_id_pass);
extras.putString("pass_selected_meal_name",mp_name_display);
intent.putExtras(extras);
context.startActivity(intent);
Toast.makeText(context, mp_name_display+" Selected",
Toast.LENGTH_SHORT).show();
No in the second Activity, I am asking the user to select the order starting date. That is also simple enough and have no issues in it. But the issue begins when I am trying to switch to the third activity.
Since my third activity content is depending on the Plan selection made in the first activity, therefore I have to transfer the selected ID to the third activity. I have it in Extra Bundle in second activity as "pass_selected_meal_plan_id".
The way I am loading the third activity is also crucial. There are two possible ways to start the third activity. First is very simple by putting onClick on the next button. I assume that it will be very simple to transfer the required selection as well. But in this case, as far as I know being a beginner in Android App Development, I will have to give a button to click and load content based on the selected Plan.
The second way is what I want to use. I am running an AsyncTask in the second activity onClick Next. It is working perfectly fine. The only this is I am unable to getExtras in onPostExecute from the previous Activity, i.e. first activity.
I am open to even using Global Variables, but don't really know how to do. Knowing what Global Variables are, I am not too keen to use them instead.
Here is my onPostExecute code:
#Override
protected void onPostExecute(String result) {
Intent intent = new Intent(ctx, SelectMeals.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
Bundle extras = new Bundle();
//Instead of "1" I want the value from previous Activity, which already available in Extras from previous Activity
extras.putString("pass_selected_meal_plan_id", "1");
//This is the second value I want to be transferred from first activity to the third activity
extras.putString("pass_selected_meal_name","Test");
intent.putExtras(extras);
ctx.startActivity(intent);
}
Would really appreciate if anyone can help.
You can use below code
In your second activity
// declare global variables
String id;
String name;
Use below code inside onCreate
Bundle bundle = getIntent().getExtras();
//Extract the data…
id = bundle.getString("pass_selected_meal_plan_id");
name = bundle.getString("pass_selected_meal_name");
Now in your Asynctask, write the code below before launching 3rd activity.
#Override
protected void onPostExecute(String result) {
Intent intent = new Intent(ctx, SelectMeals.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
Bundle extras = new Bundle();
extras.putString("pass_selected_meal_plan_id",id); // first activity data
extras.putString("pass_selected_meal_name",name); // first activity data
intent.putExtras(extras);
ctx.startActivity(intent);
}
Finally, you can get these values in third activity.
One important point I would like to highlight is that avoid using generic variable names, e.g. id. It is used just for reference in this answer but it is not a good idea. One obvious problem you may face doing so is with Refactor > Rename. It will change even the #+id in XML files.
Intent intent = new Intent(this, Page.class);
intent.putExtra("arg", getText);
startActivity(intent);
//second activity:
String passedArg = getIntent().getExtras().getString("arg");
enteredValue.setText(passedArg);
To get value from one activity to another activity without using
intents....?? I want to show edittext passed data in other activity
edittext but without using intent...?? Kindly help me is it possible
or not....??
There are many ways: event buses, SharedPreferences, through global object (application class), database, simple file. But why?
Try direct and readable style first.
if you can't bundle the values you want to save in the Intent, then you could use the SharedPreferences. More information here
This question already has answers here:
What is an Intent in Android?
(14 answers)
Closed 8 years ago.
I dont know much about intent (or android) so.. Can someone please explain me what is it exactly? i have search on the internet, A LOT.
Also what does each line of this code do?
Intent intent = new Intent (this, DisplayMessageActivity.class);
intent.putExtra("a", "b");
Thanks in advance
I suggest reading Android Intents
You couldn't have search for very long, since this is very basic topic.
I suggest you read more of Android's API guides.
Line 1 = Create message that describes what to do, in this case start "DisplayMessagActivity"
Line 2 = Add content to the message
Intent intent = new Intent (this, DisplayMessageActivity.class);
For this line, its function is to create a navigation from the current activity/page to the displaymessageactivity page.
it is like from here to there.
For this intent.putExtra("a", "b"); the purpose of this is to put like a temp storage/variable to pass to the next page for retrieval. In this case, you put the value "b" in the variable "a". With this method, you can use the value on the other activity or page.
All the above are just storing of info, it is not executed yet. if you want to execute the intent do the following
startActivity(intent);
The best example to state the behavior of Intent is it behaves like a POSTMAN that delivers message to the stated address.
Whether it may be calling service ,BroadCastRecivers ,Activity they are used in number of occassion.
Intents are asynchronous messages which allow application components
to request functionality from other Android components. Intents allow
you to interact with components from the same applications as well as
with components contributed by other applications. For example, an
activity can start an external activity for taking a picture.
Intents are objects of the android.content.Intent type. Your code can
send them to the Android system defining the components you are
targeting. For example, via the startActivity() method you can define
that the intent should be used to start an activity.
An intent can contain data via a Bundle. This data can be used by the
receiving component.
Intents can be used to start Service, call Activty, call Sub Activity, transfer the data between Activity or retrieve the data from Activity
I have some values and want to pass with activity so that I can show in TextViews of Activity, I am unable to understand such a concept, so what should I do?
Simply I want to make constructor but unable to understand it that how will it be done, I am new to android programming, so needed help.
Start by reading the documentation at developer.android.com about intents and intent extras.
In android if you launched an activity there is a method called onCreate execute automatically.You can send values using Intent to the activity and can retrieve them in the Activity
The Activity (sub)class must have a default constructor without any parameters so that the system can instanciate it at run time.
To pass "parameters" to activities, you need to use the extra bundle of the intent.
Intent i = new Intent(this, MyActivity.class);
i.putExtra("com.sample.MyParameter", 666);
startActivity(i);
See Starting An Activity
If you want to pass one value then you can use intent but if you want to pass multiple values then using "Bundle" is best way.
Bundle bundel = new Bundle();
bundel.putStringArray("key1",strings);
bundel.putStringArray("key2",stringsofids);
bundel.putString("key3", str31);
bundel.putStringArray("key4",stringsbakup);
bundel.putString("key5", str1);
bundel.putString("key6", str4);
I have a main class which has edittext box. And i have another class in the same source folder. Now i want to use the text typed in main class accessible to the another class.
any help is greatly appreciated
There are different approaches:
1) You could store the value in a static variable somewhere globally in your app (when you leave the activity = onPause) - works ok if your app activities run all in the same process, which by default is the case - unless specified differently in your manifest
2) or use the SharedPreferences (ref. to android dev docs).
3) If your one activity starts the seconds one right after, you could pass the value as an intent extra (ref. to android dev docs):
Intent intent = new Intent(this, A.class);
intent.putExtra("EXTRA_TEXT_TO_REMEMBER", editText.getText().toString());
startActivity(intent);