Question

我是android新手。我正在构建城市公交车票的应用程序。我将使用两个微调器作为开始＆＃39;点和＆＃39;目的地＆＃39;。我想匹配这两个输入并得到结果＆＃39;票价＆＃39;在textview中。请告诉我如何实现这一点。

Answer 1

使用spinner.getSelectedItem（）它返回所选对象或spinner.getSelectedItemPosition（）它将根据两个微调器的选择返回所选项目位置，你将计算你的票价

Answer 2

以下是工作示例：

<强> activity_main.xml中：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="24dp">

    <TextView
        android:id="@+id/text_result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:textSize="30dp"
        android:text="RESULT"/>

    <Spinner
        android:id="@+id/spinner_source"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp">

    </Spinner>

    <Spinner
        android:id="@+id/spinner_destination"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp">

    </Spinner>

</LinearLayout>

<强> MainActivity.java

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    TextView textResult;
    Spinner spinnerSource;
    Spinner spinnerDestination;

    String source;
    String destination;
    int cost = 0;

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

        // Views
        textResult = (TextView) findViewById(R.id.text_result);
        spinnerSource = (Spinner) findViewById(R.id.spinner_source);
        spinnerDestination = (Spinner) findViewById(R.id.spinner_destination);

        // Spinner Drop down elements
        List<String> locations = new ArrayList<String>();
        locations.add("Location 1");
        locations.add("Location 2");
        locations.add("Location 3");

        // Initialize
        source = locations.get(0);
        destination = locations.get(0);

        // Creating adapter for spinner
        ArrayAdapter<String> adapterSpinnerSource = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, locations);
        ArrayAdapter<String> adapterSpinnerDestination = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, locations);

        // attaching data adapter to spinners
        spinnerSource.setAdapter(adapterSpinnerSource);
        spinnerDestination.setAdapter(adapterSpinnerDestination);

        // Spinner item select listener
        spinnerSource.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

                // Source location
                source = parent.getItemAtPosition(position).toString();

                calculateCost();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

        spinnerDestination.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

                // Destination location
                destination = parent.getItemAtPosition(position).toString();

                calculateCost();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });
    }

    public void calculateCost() {

        if ((source.equals("Location 1") && destination.equals("Location 2"))
                || (source.equals("Location 2") && destination.equals("Location 1"))) {

            cost = 100;
        } else if ((source.equals("Location 1") && destination.equals("Location 3"))
                || (source.equals("Location 3") && destination.equals("Location 1"))) {

            cost = 200;
        } else if ((source.equals("Location 2") && destination.equals("Location 3"))
                || (source.equals("Location 3") && destination.equals("Location 2"))) {

            cost = 300;
        }

        // Output
        textResult.setText(String.valueOf(cost));
    }
}

<强>输出：

希望这会有所帮助〜

如何使用微调器项作为输入来获得结果

2 个答案: