androidstudio天气预报程序黑马程序员

以下是一个简单的天气预报程序的代码：

1. 创建一个空的 Android Studio 项目，然后在项目的 build.gradle 文件中添加以下依赖：

dependencies {
    implementation 'com.android.volley:volley:1.1.1'
}

2. 在项目的 layout 文件夹下创建一个名为 activity_main.xml 的布局文件，添加以下代码：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:id="@+id/city_input"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入城市名称"
        android:inputType="text"
        app:layout_constraintTop_toTopOf="parent"/>

    <Button
        android:id="@+id/search_btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="查询"
        app:layout_constraintTop_toBottomOf="@id/city_input"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"/>

    <TextView
        android:id="@+id/result_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        app:layout_constraintTop_toBottomOf="@id/search_btn"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        android:layout_marginTop="16dp"/>

</androidx.constraintlayout.widget.ConstraintLayout>

3. 在项目的 Java 文件夹下创建一个名为 MainActivity.java 的 Java 文件，添加以下代码：

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class MainActivity extends AppCompatActivity {

    private EditText cityInput;
    private Button searchBtn;
    private TextView resultText;

    private RequestQueue requestQueue;

    private String apiUrl = "http://apis.juhe.cn/simpleWeather/query";

    private String apiKey = "你的API Key";

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

        cityInput = findViewById(R.id.city_input);
        searchBtn = findViewById(R.id.search_btn);
        resultText = findViewById(R.id.result_text);

        requestQueue = Volley.newRequestQueue(this);

        searchBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String city = cityInput.getText().toString();
                if (city.isEmpty()) {
                    Toast.makeText(MainActivity.this, "城市名称不能为空", Toast.LENGTH_SHORT).show();
                } else {
                    searchWeather(city);
                }
            }
        });
    }

    private void searchWeather(String city) {
        String url = apiUrl + "?city=" + city + "&key=" + apiKey;

        JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                try {
                    int errorCode = response.getInt("error_code");
                    if (errorCode == 0) {
                        JSONObject result = response.getJSONObject("result");
                        JSONArray future = result.getJSONArray("future");
                        StringBuilder builder = new StringBuilder();
                        for (int i = 0; i < future.length(); i++) {
                            JSONObject item = future.getJSONObject(i);
                            String date = item.getString("date");
                            String temperature = item.getString("temperature");
                            String weather = item.getString("weather");
                            builder.append(date).append(" ").append(temperature).append(" ").append(weather).append("\n");
                        }
                        resultText.setText(builder.toString());
                    } else {
                        String reason = response.getString("reason");
                        Toast.makeText(MainActivity.this, reason, Toast.LENGTH_SHORT).show();
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Toast.makeText(MainActivity.this, "查询天气失败", Toast.LENGTH_SHORT).show();
            }
        });

        requestQueue.add(request);
    }

}

4. 将 apiKey 替换为你的 API Key。

5. 运行程序，输入城市名称并点击查询按钮，即可查询到该城市未来几天的天气情况。