我正在尝试创建一个应用程序，其中包含主要活动的食物列表和每种食物的复选框。
我按照本教程完成了整个文本和复选框的操作：http ://android-pratap.blogspot.co.il/2015/01/recyclerview-with-checkbox-example.html
但是每当我运行该应用程序时，它就不会在主屏幕上显示 RecyclerView ...（该应用程序将运行，但 RecyclerView 不存在）
如果有人可以解释我如何更改我的代码，那么它就不需要很棒的卡片了。这是我的代码：
MainAcitivity.java：（只需将 RecyclerView 与 FoodAdapter 结合）
package com.gregskl.foodreminder;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private RecyclerView recycler;
private RecyclerView.Adapter adapter;
private List<Food> foods;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
foods = new ArrayList<>();
foods.add(new Food("Grapes", true));
foods.add(new Food("Oranges", true));
recycler = (RecyclerView) findViewById(R.id.recycler);
recycler.setLayoutManager(new LinearLayoutManager(this));
adapter = new FoodAdapater(foods);
recycler.setAdapter(adapter);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
FoodAdapter.java：
package com.gregskl.foodreminder;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CheckBox;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;
/**
* Created by Gregory on 11-Sep-16.
*/
public class FoodAdapater extends RecyclerView.Adapter<FoodAdapater.ViewHolder> {
private List<Food> foods;
public FoodAdapater(List<Food> foods) {
this.foods = foods;
}
@Override
public FoodAdapater.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemLayoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.list, null);
return new ViewHolder(itemLayoutView);
}
@Override
public void onBindViewHolder(FoodAdapater.ViewHolder holder, int position) {
ViewHolder h = (ViewHolder) holder;
h.text.setText(foods.get(position).getText());
h.checkbox.setChecked(foods.get(position).isAvailable());
h.checkbox.setTag(foods.get(position));
h.checkbox.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Toast.makeText(v.getContext(), "Hey", Toast.LENGTH_LONG).show();
}
});
}
@Override
public int getItemCount() {
return foods.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView text;
public CheckBox checkbox;
public ViewHolder(View itemView) {
super(itemView);
text = (TextView) itemView.findViewById(R.id.text);
checkbox = (CheckBox) itemView.findViewById(R.id.checkbox);
}
}
}
Food.java：（食物的数据模型）
package com.gregskl.foodreminder;
/**
* Created by Gregory on 11-Sep-16.
*/
public class Food {
private String text;
private boolean available;
public Food(String text, boolean available) {
this.text = text;
this.available = available;
}
public String getText() {
return text;
}
public boolean isAvailable() {
return available;
}
public void setText(String text) {
this.text = text;
}
public void setAvailable(boolean available) {
this.available = available;
}
}
content_main.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"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.gregskl.foodreminder.MainActivity"
tools:showIn="@layout/activity_main">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_margin="5dp"
android:layout_weight="1"
android:scrollbars="vertical" />
</RelativeLayout>
列表.xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
card_view:cardCornerRadius="5dp"
card_view:cardUseCompatPadding="true" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp" >
<TextView
android:id="@+id/text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:text="name"
android:textColor="@android:color/black"
android:textSize="18sp" />
<CheckBox
android:id="@+id/checkbox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
/>
</RelativeLayout>
</android.support.v7.widget.CardView>