Quantity Button with RadioGroup To Calculate Subtotal Price-CodePudding

Hello I have been struggling to figure out how to get the subtotal with my quantity increment and decrement buttons for subtotal.

What I want is after the customers chooses a type the price will show on the bottom. Then if they would like multiple orders they can press the button and the price will change as well depending if they increase or decrease. Here is the Code

MainActivity

public class expresso_item1 extends AppCompatActivity  {

private Spinner spinner;

RadioGroup radioGroup;
RadioButton radioButton;
TextView textView;


TextView value;
int count = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_expresso_item1);

    value = (TextView) findViewById(R.id.quantity1);
    radioGroup = findViewById(R.id.radioGroup);
    textView = findViewById(R.id.total1);



}

public void RButton (View v){
    int radioID = radioGroup.getCheckedRadioButtonId();
    switch(radioID){
        case R.id.type1:
            textView.setText("$" "5");
            break;
        case R.id.type2:
            textView.setText("$" "10");
            break;
        case R.id.type3:
            textView.setText("$" "12");
            break;
    }


}

public void plus (View v){
    count  ;
    value.setText(""   count);
}

public void minus (View v){
    if (count <= 0 ) count = 0;
    else count--;
    value.setText(""   count);
}

}

Currently only shows the type price the customer wants. Any help is appreciated!

Here is a pic of the Design Layout: Design

CodePudding user response：

Try this instead

Initialize another global variable to get the current price below the count

int count = 0
int currentPrice = 0

Then in the RButton() set the new value for the currentPrice

public void RButton (View v){
    int radioID = radioGroup.getCheckedRadioButtonId();
    switch(radioID){
        case R.id.type1:
            textView.setText("$" "5");
            currentPrice = 5
            break;
        case R.id.type2:
            textView.setText("$" "10");
            currentPrice = 10
            break;
        case R.id.type3:
            textView.setText("$" "12");
            currentPrice = 15
            break;
    }


}

Then in the plus and minus function

public void plus (View v){
    count  ;
    value.setText(""   String.valueOf(count * currentPrice));
}

public void minus (View v){
    if (count <= 0 ) count = 0;
    else count--;
    value.setText(""   String.valueOf(count * currentPrice));
}
}

CodePudding user response：

this is how I would have done, make a global variable quantity (instead of count) and initialise with value 0.

I will set this to quantity textview, it will increase whenever user presses on image button and similarly decrease on -.

I will also make another variable rate initialise it to 0.

//global variable
private val quantity = 0
. 
. 
. 
quantityTexview.text = 
quantity.toString() 
val rate = 0
//it's value will change depending on 
//selected radio button ($5, $10,$12) 
subtotal.text = quantity * rate 
//set this to subtotal textview 
subtotalTextview.text = 
subtotal.toString()