java - 选择带有变量的 Spinner，

Question

我是 Android 新手。我正在尝试选择微调选项并将其乘以用户输入。 (这是一个将比萨饼的数量乘以每个比萨饼的成本的应用程序)这有意义吗？因此，我能够处理一个微调器选项并获得正确答案，但我不知道如何编写多个微调器选项的代码。

这是Java:

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

import java.text.DecimalFormat;

public class MainActivity extends AppCompatActivity {

    //below is where I have placed the values associated with the Pizza Choices//
    //each one is under the txtPizza string array and is referenced//

    double costCheese = 4.50;
    double costPepperoni = 5.75;
    double costVeggie = 4.75;
    double costGluten = 5.30;
    double costPersonal = 3.15;

    int txtnumber;
    double txtresult;

    String txtGroup;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    final EditText amount = (EditText)findViewById(R.id.txtnumber);
    final Spinner type =(Spinner)findViewById(R.id.txtGroup);


        Button cost = (Button)findViewById(R.id.OrderBtn);
        cost.setOnClickListener(new View.OnClickListener() {
            final TextView result = ((TextView)findViewById(R.id.txtResult));
            @Override
            public void onClick(View v) {
                txtnumber = Integer.parseInt(amount.getText().toString());
                txtresult = costCheese * txtnumber;
                DecimalFormat currency = new DecimalFormat("$###,###.##");
                result.setText("Cost for this order is " + currency.format(txtresult)); }




        });



    }}

Answer 1

好吧，您需要一个适配器来说明您想要的选项。

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
array_spinner=new String[5];
array_spinner[0]="option1";
array_spinner[1]="option2";
array_spinner[2]="option3";
array_spinner[3]="option4";
array_spinner[4]="option5";
Spinner s = (Spinner) findViewById(R.id.Spinner01);
ArrayAdapter adapter = new ArrayAdapter(this,
android.R.layout.simple_spinner_item, array_spinner);
s.setAdapter(adapter);
}

检查 this了解更多关于微调器的信息。