如何检查使用Android单击的按钮？

Question

I have 2 activities, the first activity include two buttons and the second activity also include 2 buttons. I need when I click on the first button of the first activity, the second activity started and the first button of the second activity become "invisible" and the second button "visible". again if the user back to the first activity and click the second button, then the second activity started where the second button become "invisible" and first one "visible".

I just need to know how to decide that which button from the first activity is pressed by the user. is there any specific method , or if any way?

I tried doing it by set a variable (int i) as a global variable in the first activity and if the user click the first button then this (i) changes to 1 (Same Thing to Second Button), and I set a condition in the second activity that call this (i) variable as:

MainActivity a=new MainActivity();
         if(a.i==0){
              //do this
         }
         else if(a.i==1){
              //do this
         }

but this doesn't work and the second activity always get this (i) as it's equal to (0).

Answer 1

You should start your second activity by using an Intent. For this Intent you can put some Arguments. In your First Activity:

Button b1 = (Button)findViewById(R.id.button1);
Button b2 = (Button)findViewById(R.id.button2);
// Set OnClickListeners
b1.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View view) {
       // Start Activity
       Intent intent = new Intent(this, Activity2.class);
       intent.putExtra("buttontohide", 0); // Hide Button 0
       startActivity(intent);
   }
});

b2.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View view) {
       // Start Activity
       Intent intent = new Intent(this, Activity2.class);
       intent.putExtra("buttontohide", 1); // Hide Button 1
       startActivity(intent);
   }
});

In your Second Activity:

Intent myIntent = getIntent();
int i = myIntent.getExtras().getInt("buttontohide");

Answer 2

You can pass parameters into extra before starting second activity. Use it to tell to second activity which button is clicked. In onCreate() method of second activity analyze extra to define which button must be hidden.

Answer 3

 MainActivity a = new MainActivity(); 

You're initializing the Activity again. But in your case, take a static variable instead.

Do something like this.

In your MainActivity.java declare a static variable

public class MainActivity extends Activity {
  public static int a = 0;
  // Rest of your code
}

Now from the second activity check whether the value is 0 or 1 like this

public class SecondActivity extends Activity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    ...
    if(MainActivity.a == 0) { /*Do something*/ }
    else { /*Do something*/ }  
  }
}

Answer 4

I assumed that you know all the code how to make a button visible and invisible. first declare an int variable in your first activity and pass it to second activity using getIntent, after that using if else logic capture your variable value and put your code to make the button invisible.

Answer 5

You could use a Bundle to pass data from Activity A to Activity B:

In Activity A:

... onClick() {
    ...

    Intent intent = new Intent(this, ActivityB.class);
    intent.putExtra("ButtonNR", iButtonNR);

    startActivity(intent);
}

In Activity B:

public class ActivityB extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        ...

        Bundle bundle = getIntent().getExtras();
        int iButtonNR = bundle.getInt("ButtonNR");

        switch (iButtonNR) {
            case 0:
                //do something...
                break;
            case 1:
                //do another thing...
                break;
        }
  }
}