Develop Reference

How to use the same UI with multiple java files? ANDROID JAVA

I'm a newbie and I'm working on a Unit Converter.
I would like to open the same UI regardless of which button I click(Weight or Length)
main_activity.xml UI
Below is the UI I want to open: activity_conversion.xml UI
And I would like each button in the main_activity to run on a different java class.
So, (minus the main_activity.java and it's .xml file)
I have 1 xml file(activity_conversion.xml) and 2 java files one for each button of the main_activity.xml
activity_main.xml Weight button
android:onClick="weightPage"
activity_main.xml Length button
android:onClick="lengthPage"
MainActivity.java
public void weightPage(View view){
Intent intent = new Intent(this, WeightActivity.class);
startActivity(intent);
}
public void lengthPage(View view) {
Intent intent2 = new Intent(this, LengthActivity.class);
startActivity(intent2);
}
Length_Activity.java code for Length button
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_conversion);
}
setContentView() method doesn't work for me:(
Thanks in advance!

I would like to open the same UI regardless of which button I click(Weight or Length)
You can do that by creating an activity and its layout XML file. And then start that activity via explicit intent like this:
//Place this code inside the onClick method
Intent intent = new Intent(SoucreActivity.this, DestinationActivity.class);
startActivity(intent);
And I would like each button in the main_activity to run on a different java class.
No, you cannot. All UI elements on a screen are always in the same activity; they cannot run on different java classes. (Unless you are using fragments of which you need not worry about as you are a newbie)
Apparently, you want the two buttons in your main activity to open the same activity. Which you can achieve using intents using the code snippet mentioned above.

TextView from SecondActivity become visible after a button from MainActivity is pressed?

I'm very new to Android Studio Development and I was wondering how to do this, when I click a button on MainActivity, it will direct me to secondActivity where the text become visible (Originally TextView will not be visible until the button from MainActivity is pressed)
imageButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, SecondActivity.class);
String status = "Success!";
intent2.putExtra("Status",status);
startActivity(intent);
}
});
I want to make an if-else statement for this (on SecondActivity page) where if user straight away go to SecondActivity, it will not display any text there. But if pressed the button on MainAcitivty page, the system will go to SecondActivity with the TextView displayed.
Thanks!

Basically, there are several approaches you can do that.
Use intents pass data
Sure you pass a boolean type or whatever you want into this intent, I think this is the approach you are trying to make here. So I can give you an example:
In your first activity you can do something like this,
button.setOnClickListener {
val intent = Intent(this#MainActivity, SecondActivity::class.java).apply {
val status = true
putExtra("Status", status)
}
startActivity(intent)
}
And in your second activity, in your need to override onCreate to parse your intents to decide your text want to display or not.
val status = intent.extras?.getBoolean("Status")
if(status) {
hideText()
} else {
showText()
}
the other approach you can deal with it is try to create singleton class to keep the status in this class, and based this singleton class status, you may choose to hide/show your text. However this solution isn't the recommended way to do it. Because global state is bad for testing and just pollute the code.

Save settings button and back to previous activity

I have an activity that has edit text and you can type your name in it, and when you click Save button you will be redirected to MainActivity, but I don't want to open MainActivity by Intent, I make that save button save your name with shared prefs and everything works fine but I don't want to open my Main in Intent I want that when I clicked on save button the current activity that saves data close and previous activity open.
sorry for my bad English.
this is my code for save button
submitButt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (v.getId() == submitButt.getId()) {
String name = inputName.getText().toString().trim();
if (isValidInput(name)) {
Intent setint = new Intent(SettingsActivity.this, MainActivity.class);
setint.putExtra("name", name);
saveData();
startActivity(setint);
Toast.makeText(SettingsActivity.this, "Settings Saved", Toast.LENGTH_SHORT).show();
}
}
}

Then you just open the PreviousActivity instead of the MainActivity. Add a checker inside the PreviousActivity if "name" has data or not. You can also use finish(); this will kill the activity.
** Update **
In your MainActivity, let's say you have TextView name. Add:
#Override
public void onResume(){
super.onResume();
// Check your variable if it has value or none
textViewName.setText(variableForSharedPref)
}
Then you can proceed with usual process to go in Settings and Go Back to MainActivity.

How to go another Activity using function instead of Button widget

I hope if someone help me in this ,
in my projet I am trying to open another avtivity used voice command Ex, say "one " it should compare if the string is equal to what I? have it should switch to another activity or external activity such as Phone call, Camera. What I did here, I store the recognized ward in Edittext and store it in string and compare it . my 2 projects counted on how to do this
Inside onCreate:
final Button btntx = (Button)findViewById(R.id.btn1);
final EditText edittxt1 = (EditText)findViewById(R.id.edttxt);
btntx.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent (Intent.ACTION_DIAL); // sow the Dial window
intent.setData(Uri.parse("tel:"));
startActivity(intent);
);
}
////////////////////////// outside the onCreate //////// Function after I get the result from the Speech recognizer and call this function to see if the what it said is equal to my keyword . SO i need to call the button to open that activity
String gwdata= edtxt.getText().toString(); // data from EditText
if (gwdata.equals("One"))
{
Toast.makeText(getBaseContext(),"They are equal", Toast.LENGTH_SHORT).show();
// Here Do someting to go to another activity
}
Thnks guys in advance .

How do I bind a button to another xml file?

I'm creating my first mobile app and I'm trying to bind a button to go straight to another xml file. It seems like such an easy answer but I can't find the solution anywhere. I'm using Eclipse as my IDE and using the Android ADT bundle, if that's at all relevant.

Put this in onCreate:
findViewById(R.id.my_button).setOnClickListener(new View.OnClickListener {
#Override
public void onClick() {
startActivity(new Intent(MainActivity.this, OtherActivity.class))
}
});
Replace my_button with the id of your button and MainActivity.this with the name of your main activity class.this and OtherActivity with the name of your other activity.class.

Are you asking how to create a layout with button that brings different layout? If so, you can drag button on your layout and put method in the "On Click" property of the button, something like myClick and then in your code add method
public void myClick(View v) {
startActivity(new Intent(this, MyNewActivity.class));
}
Make sure to declare new activity in AndroidManifest
Hope it helps

In your xml file, add this line of code to your button:
<Button>
//other button properties here
android:onClick='onNextPage'
</Button>
and in the activity/java file for that page, do this:
private void onNextPage(View view){
Intent intent = new Intent(this, nextActivity.java);
startActivity(intent);
}
when you click the button, you'll go to nextActivity.java or whatever you named your second page to be.