如何使一个按钮执行一项任务，该任务取决于Java android中单击了哪个先前的按钮？

Question

I am trying to make a simple math training app with levels , the plan is to make the user press on the button of the level he wants then the Go button will appear when he press Go the app starts and it generates random numbers based on the difficulty of the level he chose, now how to make the Go button play the app according to the level has been pressed , this is what i have tried so far but for some reason the app just crashes . ps this isn't the full code just the related issue of the code "

public void levelsWay(View view){

if (view.getTag().toString().equals("L1")) {
    a = rano.nextInt(21);
    b = rano.nextInt(51);
}

else if (view.getTag().toString().equals("L2")){
    a = rano.nextInt(101);
    b = rano.nextInt(151);
}
else if (view.getTag().toString().equals("L3")){
    a = rano.nextInt(151);
    b = rano.nextInt(501);
}
else if (view.getTag().toString().equals("L4")){
    a = rano.nextInt(501);
    b = rano.nextInt(1001);

}

}

public void generateQuestions() {

    levelsWay(null);

    c=rano.nextInt(4);
 switch (c) {
     case 0:op='+';
         break;
     case 1:op='-';
         break;
     case 2:op='*';
         break;
     case 3:op='/';
         break;
         default:op='?';
 }
    sumtextview.setText(Integer.toString(a) + op + Integer.toString(b));

}

public void start(View view) {
    starts.setVisibility(View.INVISIBLE);
    Gamelayout.setVisibility(View.VISIBLE);
    playAgain(findViewById(R.id.pp));


}

Answer 1

You need to set the tag inside your xml layout file where the buttons are stated and then inside your code you getTag from the view and use it accordingly something as follows

Set tag for each button as follows

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/btn_level_1"
    android:tag="L1" // Setting tag here />

Then inside the onClick listener do the following

btn = (Button)findViewById(R.id.firstButton);
btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        String level = view.getTag().toString();
        Log.d(TAG, "Level Selected : " + level);
        // Apply the rest of the logic
    }
});