Question

android programming

Bill amount -----------------

Percent ------------------(using seek bar)

Tip

Total (Bill amount + percent)

Split bill (use Spinner)(no way, one way , two way, three way)

per person ---(use if and else to give manual amount per person)

Answer 1

you initialised apply button as seekbar,this is the only mistake you did.after correcting the statements the activity calss is as follows

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.TextView;

public class TipCalculatorActivity extends AppCompatActivity {

private EditText et_bill_amount;
private TextView tv_tip,tv_total,tv_percent;
private SeekBar seekBar;
private Button applyButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Initialize edittext, seekbar, textViews and apply button.
et_bill_amount=(EditText)findViewById(R.id.billAmountEditText);
tv_total=(TextView)findViewById(R.id.totalTextView);
tv_tip=(TextView)findViewById(R.id.tipTextView);
tv_percent=(TextView)findViewById(R.id.percentTextView);
seekBar=(SeekBar)findViewById(R.id.percentSeekBar);
applyButton=(Button)findViewById(R.id.applyButton);

applyButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
calculateAndDisplay();
}

});
}

private void calculateAndDisplay() {
//Get seekbar progress value
int percent=seekBar.getProgress();

//Set percent value to percentTextView
tv_percent.setText(String.valueOf(percent)+"%");

//Extract entered bill amount and store in billAmount.
float billAmount=Float.valueOf(et_bill_amount.getText().toString());

//Calculate tip and total.
float tip=billAmount*((float)percent/100);
float total=billAmount+tip;

//Set tip and total values respectively
tv_tip.setText("$"+String.valueOf(tip));
tv_total.setText("$"+String.valueOf(total));
}
}