我正在学习如何使用 Volley。我已将响应成功记录到 System.out.printIn 并在 logcat 中看到它用于数组中的单个项目。当我有多个项目时,我会为 FOR 循环而苦苦挣扎。我无法弄清楚如何遍历数据。有人可以帮我演示如何操作吗。
我的主要 Activity
package hfad.com.volley_listview_array;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import com.android.volley.Request;
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;
import java.util.ArrayList;
public class MainActivity extends Activity {
ArrayAdapter<String> adapter;
ArrayList<String> items;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TextView mTextView = (TextView) findViewById(R.id.textView);
String url = "https://reqres.in/api/users?page=2";
JsonObjectRequest jsonRequest = new JsonObjectRequest
(Request.Method.GET, url, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
// the response is already constructed as a JSONObject!
try {
response = response.getJSONObject("data");
//for loop goes here? How? I get i already defined in scope
for (int i = 0, i < response.length(), i++);
//String site = response.getString("first_name"),
// network = response.getString("last_name");
//System.out.println("firstname: "+site+"\nLastname: "+network);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
}
});
Volley.newRequestQueue(this).add(jsonRequest);
}}
而我的 activity_main.xml 不需要在列表中显示结果。只想把所有的数据一个接一个地堆起来。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="10dp"
tools:context=".MainActivity">
<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView" />
<!--
<ListView
android:id="@+id/listv"
android:layout_width="match_parent"
android:layout_height="89dp"></ListView>
-->
</LinearLayout>
我的数据来自这个测试 api https://reqres.in/api/users?page=2
{"page":"2","per_page":3,"total":12,"total_pages":4,"data":[{"id":4,"first_name":"eve","last_name":"holt","avatar":"https://s3.amazonaws.com/uifaces/faces/twitter/marcoramires/128.jpg"},{"id":5,"first_name":"gob","last_name":"bluth","avatar":"https://s3.amazonaws.com/uifaces/faces/twitter/stephenmoon/128.jpg"},{"id":6,"first_name":"tracey","last_name":"bluth","avatar":"https://s3.amazonaws.com/uifaces/faces/twitter/bigmancho/128.jpg"}]}
我得到了要在我的 logcat 中显示的数据,但它只显示第一项。如何遍历所有记录。感谢您的帮助。
最佳答案
String url = "https://reqres.in/api/users?page=2";
JsonObjectRequest jsonRequest = new JsonObjectRequest
(Request.Method.GET, url, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
JSONArray jsonArray = response.getJSONArray("data");
JSONObject jsonInnerObject;
for (int k = 0; k< jsonArray.length(); k++){
jsonInnerObject=new JSONObject(jsonArray.get(k).toString());
String site = jsonInnerObject.getString("first_name"),
network = jsonInnerObject.getString("last_name");
System.out.println("firstname: "+site+"\nLastname: "+network);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
}
});
Volley.newRequestQueue(this).add(jsonRequest);`
注意:data包含JSONObject的JSONArray
关于java - Android Volley 循环响应,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43576603/