I want to pass information from one class to another for example:
TextView t;
I have a TextView here, called t and it is in the Main class.
Now in the Main2 class:
t.setText("TextView saiu da Main para a Main2");
I've already tried to put public but still says that the t variable does not exist on Main2.
To access a variable of another class, simply state that the variable is estática , which will allow you to access it without needing an object:
public static TextView t;
To access another class, you must also indicate the class in which the variable exists:
Main.t.setText("TextView saiu da Main para a Main2");
example:
public class Example{
public static TextView t;
}
public class Example2{
public static void main(String[] args){
Example.t.setText("TextView saiu da Main para a Main2");
}
}
I can suggest 3 options
1 Option
Use singleton, or simply define a class as static.
public class Singleton {
private static Singleton uniqueInstance;
private Singleton() {
}
public static synchronized Singleton getInstance() {
if (uniqueInstance == null)
uniqueInstance = new Singleton();
return uniqueInstance;
}
}
Read more at: Java Singleton Project Pattern link
2 option
Defining global variables or objects, you can create a Class Application on Android and set global variables or even the singleton.
Example .
3 Option
You can pass variables or objects by Intent to other activities or fragments
Activity 1
Intent i=new Intent("....");
i.putExtra("TEXT", "Olá");
startActivity(i);
Activity 2
TextView text = (TextView) findViewById(R.id.text);
Bundle bundle = getIntent().getExtras();
String var_intent = bundle.getString("TEXT");
text .setText(var_intent );
You can use the following code below:
Main1 class:
import android.widget.TextView;
public class Main1 {
private TextView t;
public TextView getT() {
return t;
}
}
Main2 class:
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class Main2 extends Activity {
private TextView t;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Main1 objeto = new Main1();
t = objeto.getT();
t = (TextView) findViewById(R.id.textView1); //aqui você põem o nome do id do textView
t.setText("TextView saiu da Main para a Main2");
}
}