Starting different activities from MainActivity

Question

I'm new here and I think I have made a mistake in Java but I have no idea how to correct it. Most of the people with similar issue had much more complicated projects and I couldn't resolve my issue by looking at their code.

I want to use different buttons (9 of them) to start different activities, but when I started with adding the second, only the activity 1 (LeftArmActivity) popped up. Whatever I changed in the XML to call the proper method for HeadActivity to launch, only the LeftActivity launches. I've got a hint from other topics that it may be caused by overwriting of the intent, but I have no idea how to fix this. I tried to use getActivity() but it just crashed. Could you please help me with this?

@UPDATE

Okay, I used the switch recommended below, but now the app won't start at all :/

 public class MainActivity extends AppCompatActivity {

Context context = this;
Button LeftArmOpener = (Button) findViewById(R.id.LeftArmOpener);
Button HeadOpener = (Button) findViewById(R.id.HeadOpener);
Button RightArmOpener = (Button) findViewById(R.id.RightArmOpener);
Button CreditsOpener = (Button) findViewById(R.id.CreditsOpener);
Button TrunkOpener = (Button) findViewById(R.id.TrunkOpener);
Button NextOpener = (Button) findViewById(R.id.NextOpener);
Button RightLegOpener = (Button) findViewById(R.id.RightLegOpener);
Button ExitOpener = (Button) findViewById(R.id.ExitOpener);
Button LeftLegOpener = (Button) findViewById(R.id.LeftLegOpener);

protected View.OnClickListener mClick;


protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mClick = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            switch (v.getId()) {
                case R.id.RightArmOpener: {
                    Intent i1 = new Intent(context, LeftArmActivity.class);
                    startActivity(i1);
                    break;
                }
                case R.id.HeadOpener: {
                    Intent i2 = new Intent(context, HeadActivity.class);
                    startActivity(i2);
                    break;
                }
                case R.id.LeftArmOpener: {
                    Intent i3 = new Intent(context, LeftArmActivity.class);
                    startActivity(i3);
                    break;
                }
                case R.id.CreditsOpener: {
                    Intent i4 = new Intent(context, CreditsActivity.class);
                    startActivity(i4);
                    break;
                }
                case R.id.TrunkOpener: {
                    Intent i5 = new Intent(context, TrunkActivity.class);
                    startActivity(i5);
                    break;
                }
                case R.id.NextOpener: {
                    Intent i6 = new Intent(context, NextActivity.class);
                    startActivity(i6);
                    break;
                }
                case R.id.RightLegOpener: {
                    Intent i7 = new Intent(context, RightLegActivity.class);
                    startActivity(i7);
                    break;
                }
                case R.id.ExitOpener: {
                    Intent i8 = new Intent(context, ExitActivity.class);
                    startActivity(i8);
                    break;
                }
                case R.id.LeftLegOpener: {
                    Intent i9 = new Intent(context, LeftLegActivity.class);
                    startActivity(i9);
                    break;
                }
                //create this for all 9 buttons
            }

        }

    };

    LeftArmOpener.setOnClickListener(mClick);
    HeadOpener.setOnClickListener(mClick);
    RightArmOpener.setOnClickListener(mClick);
    CreditsOpener.setOnClickListener(mClick);
    TrunkOpener.setOnClickListener(mClick);
    NextOpener.setOnClickListener(mClick);
    RightLegOpener.setOnClickListener(mClick);
    ExitOpener.setOnClickListener(mClick);
    LeftLegOpener.setOnClickListener(mClick);


}

}

Answer 1

Update your Code with this

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate (Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

}

public void openHead(View view){
    startActivity(new Intent(MainActivity.this, LessonOne.class));
    //startActivity(t);
}


public void openLeftArm(View view){
    Intent i = new Intent(MainActivity.this, LeftArmActivity.class);
    startActivity(i);
}
}

//the problem is you are calling startActivity() two time and Passing getActivity() from Actvity.

Answer 2

You said you have 9 buttons so i think u should use switch case in such scenarios see the following code:-

Here is how my Button looks in xml no android:onClick is used here

    <Button
    android:id="@+id/btn1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Button 1" />

This part goes in Activity:-

    Context context = this;
    Button btn1 = (Button) findViewById(R.id.btn1);
    Button btn2 = (Button) findViewById(R.id.btn2);
    Button btn9 = (Button) findViewById(R.id.btn9);

    btn1.setOnClickListener(mClick);
    btn2.setOnClickListener(mClick);
    btn9.setOnClickListener(mClick);


View.OnClickListener mClick = new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn1: {
                Intent i1 = new Intent(context, First.class);
                startActivity(i1);
                break;
            }
            case R.id.btm2: {
                Intent i2 = new Intent(context, Second.class);
                startActivity(i2);
                break;
            }
            //create this for all 9 buttons
        }

    }
};

Answer 3

On the top declare your button; (before the oncreate method)

 Button yourbuttonname;

Then on the oncreate method:

declare the view of the button:

yourbuttonname = (Button) findViewById(R.id.buttonNameInYourXML);
 yourbuttonname.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
       Intent intent = new Intent(ActualActivity.this, ActivityYouWantToGo.class);
                intent.putExtra("tag",valueassociatedtotag); // if you want to pass some data
                startActivity(intent)
            }
        });