我正在使用RecyclerView和自定义适配器，但它没有显示数据。
adapter.class的代码
public class AdapterList extends RecyclerView.Adapter<AdapterList.ViewHolder> {
Context context;
ArrayList<HashMap<String, String>> list_data;
public AdapterList(Appetizer1 appetizer1, ArrayList<HashMap<String,String>> list_data){
this.context = appetizer1;
this.list_data = list_data;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_iitem,null);
return new ViewHolder(view) ;
}
@Override
public void onBindViewHolder(AdapterList.ViewHolder holder, int position) {
Glide.with(context).load("http://kelompokdua.hol.es/pic/" + list_data.get(position)
.get("gambar")).crossFade().placeholder(R.mipmap.ic_launcher)
.into(holder.imgfood);
holder.txtfood.setText(list_data.get(position).get("nama"));
holder.txtid.setText(list_data.get(position).get("id"));
holder.txtharga.setText(list_data.get(position).get("harga"));
}
@Override
public int getItemCount() {
return list_data.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
TextView txtfood,txtid,txtharga;
ImageView imgfood;
public ViewHolder (View itemView){
super(itemView);
txtfood = (TextView) itemView.findViewById(R.id.tv_nama);
txtid = (TextView) itemView.findViewById(R.id.tv_id);
txtharga = (TextView) itemView.findViewById(R.id.tv_harga);
imgfood = (ImageView) itemView.findViewById(R.id.thumbnail);
}
}
}
mainactivity.class的代码
public class Appetizer1 extends AppCompatActivity {
private RecyclerView lvfood;
private RequestQueue requestQueue;
private StringRequest stringRequest;
ArrayList<HashMap<String, String>> list_data;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_appetizer1);
String url = "http://kelompokdua.hol.es/private_html/show.php";
lvfood = (RecyclerView) findViewById(R.id.rv1);
LinearLayoutManager llm = new LinearLayoutManager(this);
llm.setOrientation(LinearLayoutManager.VERTICAL);
lvfood.setLayoutManager(llm);
requestQueue = Volley.newRequestQueue(Appetizer1.this);
list_data = new ArrayList<HashMap<String, String>>();
stringRequest = new StringRequest(Request.Method.GET, url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Log.d("response", response);
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray jsonArray = jsonObject.getJSONArray("");
for (int a = 0; a < jsonArray.length(); a++) {
JSONObject json = jsonArray.getJSONObject(a);
HashMap<String, String> map = new HashMap<String, String>();
map.put("id", String.valueOf(json.getInt("id")));
map.put("nama", json.getString("nama"));
map.put("harga", String.valueOf(json.getInt("harga")));
map.put("gambar", json.getString("gambar"));
list_data.add(map);
AdapterList adapter = new AdapterList(Appetizer1.this, list_data);
lvfood.setAdapter(adapter);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(Appetizer1.this, error.getMessage(), Toast.LENGTH_LONG).show();
}
});
requestQueue.add(stringRequest);
}}
这是我的json结果：
[[{"id":"1","nama":"Martabak","harga":"25000","gambar":"http:\/\/kelompokdua.hol.es\/pic\/martabak.jpg"},{"id":"2","nama":"Ayam Goreng","harga":"20000","gambar":"http:\/\/kelompokdua.hol.es\/pic\/ayam.jpg"},{"id":"3","nama":"Nasi Goreng","harga":"15000","gambar":"http:\/\/kelompokdua.hol.es\/pic\/nasigor.jpg"},{"id":"4","nama":"Cola","harga":"5000","gambar":"http:\/\/kelompokdua.hol.es\/pic\/cocacola.jpg"},{"id":"5","nama":"Es teh manis","harga":"3000","gambar":"http:\/\/kelompokdua.hol.es\/pic\/esteh.jpg"},{"id":"6","nama":"Jus","harga":"18000","gambar":"http:\/\/kelompokdua.hol.es\/pic\/juice.jpg"},{"id":"7","nama":"Pasta","harga":"20000","gambar":"http:\/\/kelompokdua.hol.es\/pic\/pasta.jpg"}]]
这是我的adapterlist.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:id="@+id/cardView">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:orientation="vertical">
<ImageView
android:id="@+id/thumbnail"
android:layout_width="match_parent"
android:layout_height="167dp"
app:srcCompat="@mipmap/ic_launcher" />
<TextView
android:id="@+id/tv_id"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/tv_nama"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/tv_harga"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
</android.support.v7.widget.CardView>
</RelativeLayout>
和这个mainactivity.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.kelompok3.restaurantapp.restoranfixx.Isimenu.Appetizer1">
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.kelompok3.restaurantapp.restoranfixx.Isimenu.Appetizer1">
<android.support.v7.widget.RecyclerView
android:id="@+id/rv1"
android:layout_width="368dp"
android:layout_height="495dp"
android:visibility="visible"
tools:layout_editor_absoluteX="8dp"
tools:layout_editor_absoluteY="8dp" />
</RelativeLayout>
我没有在logcat上看到任何错误，我很困惑。它只显示一个空白的布局。我改变了能见度但没有发生任何事情。我现在尝试任何建议后问题是
E/RecyclerView: No adapter attached; skipping layout
答案 0 :(得分：0)
您的代码看起来很完美。只需检查您的Recyclerview在XML文件中是否可见。可能是你错误地使你的能见度消失了。只需检查并告诉我，或者您可以通过以下代码进行检查
AdapterList adapter = new AdapterList(Appetizer1.this, list_data);
lvfood.setAdapter(adapter);
lvfood.setVisibility(View.VISIBLE);
答案 1 :(得分：0)
显示recyclelerview的可见性，如下所示： -
lvfood.setVisibility(View.VISIBLE);
lvfood.setAdapter(adapter);
答案 2 :(得分：0)
将以下行移出for循环
AdapterList adapter = new AdapterList(Appetizer1.this, list_data);
lvfood.setAdapter(adapter);
另外请确保列表在xml中可见。
lvfood.setVisibility(View.VISIBLE);
答案 3 :(得分：0)
我会尝试移动这两行：
AdapterList adapter = new AdapterList(Appetizer1.this, list_data);
lvfood.setAdapter(adapter);
您应该将它们从for循环移出，否则您为该数组中的每个JSONObject创建并设置一个新的Adapter。 我还建议创建一个包含JSONObject属性的类，这样就可以使用List而不是HashMap。
另外，正如其他人建议的那样，尝试检查RecyclerView可见性：
lvfood.setVisibility(View.VISIBLE);
答案 4 :(得分：0)
问题出在Glide的链接中。您正在存储JSON的完整链接。但是当您尝试加载该图像时，您还会添加标题链接，这就是图像无法加载的原因。
只需像这样更改Gilde链接即可。
Glide.with(context).load(list_data.get(position).get("gambar")).crossFade().placeholder(R.mipmap.ic_launcher).into(holder.imgfood);
答案 5 :(得分：0)
将此代码替换为响应（）方法
try {
JSONArray response1=new JSONArray(response);
JSONArray jsonArray = response1.getJSONArray(0);
for (int a = 0; a < jsonArray.length(); a++) {
JSONObject json = jsonArray.getJSONObject(a);
try {
HashMap<String, String> map = new HashMap<String, String>();
map.put("id", String.valueOf(json.getInt("id")));
map.put("nama", json.getString("nama"));
map.put("harga", String.valueOf(json.getInt("harga")));
map.put("gambar", json.getString("gambar"));
list_data.add(map);
} catch (JSONException e1) {
e1.printStackTrace();
}
}
AdapterList adapter = new AdapterList(getApplicationContext(), list_data);
lvfood.setAdapter(adapter);
}catch (JSONException e) {
e.printStackTrace();
}
并在Arraylist中宣布
ArrayList<HashMap<String, String>> list_data=new ArrayList<>();