当我使用所选复选框滚动listView时，当我向后滚动时，它们将被取消选中。我知道这是因为Recycler View，但我不知道如何处理复选框状态。请帮助我解决这个问题。我通过看到不同的教程和视频来尽我所能，但却得不到我需要的东西。我是android开发的新手。所有代码都在下面。请帮助我。
Category.java
/**
* Created by Ali on 14-06-2017.
*/
public class Category {
private String categoryName;
private int imageResourceId;
private boolean isChecked;
public Category(String categoryName, int imageResourceId)
{
this.categoryName = categoryName;
this.imageResourceId = imageResourceId;
}
public Category(String categoryName, int imageResourceId, boolean isCheck)
{
this.categoryName = categoryName;
this.imageResourceId = imageResourceId;
this.isChecked = isCheck;
}
public void setCategoryName(String categoryName)
{
this.categoryName = categoryName;
}
public String getCategoryName()
{
return categoryName;
}
public void setImageResourceId(int imageResourceId)
{
this.imageResourceId = imageResourceId;
}
public int getImageResourceId()
{
return imageResourceId;
}
public boolean getIsChecked()
{
return this.isChecked;
}
public void setIsChecked(boolean value)
{
this.isChecked = value;
}
}
CategoryAdapter.java
import android.app.Activity;
import android.content.Context;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
/**
* Created by Ali on 14-06-2017.
*/
public class CategoryAdapter extends ArrayAdapter<Category> {
private int imageResourceId;
public CategoryAdapter(Activity context, ArrayList<Category> categories, int newImageResourceId) {
super(context, 0, categories);
imageResourceId = newImageResourceId;
}
public CategoryAdapter(CategoryActivityScreen activityScreen, ArrayList<Category> categories) {
super(activityScreen, 0, categories);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// Check if the existing view is being reused, otherwise inflate the view
View listItemView = convertView;
if (listItemView == null) {
listItemView = LayoutInflater.from(getContext()).inflate(
R.layout.list_item, parent, false);
}
//Below code is before the extra code is written
// Get the {@link AndroidFlavor} object located at this position in the list
Category currentCategory = getItem(position);
ImageView imageView = (ImageView) listItemView.findViewById(R.id.image);
imageView.setImageResource(currentCategory.getImageResourceId());
imageView.setVisibility(View.VISIBLE);
TextView categoryTextView = (TextView) listItemView.findViewById(R.id.categoryNames);
// Get the version name from the current AndroidFlavor object and
// set this text on the name TextView
categoryTextView.setText(currentCategory.getCategoryName());
CheckBox checkBox = (CheckBox) listItemView.findViewById(R.id.checkbox);
//checkBox.setChecked(false);
checkBox.setChecked(currentCategory.getIsChecked());
return listItemView;
}
}
CategoryActivityScreen.java
import android.content.Context;
import android.media.AudioManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
/**
* Created by Ali on 14-06-2017.
*/
public class CategoryActivityScreen extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.category_list);
//Currently dummy list is populated
// Create a list of categories
final ArrayList<Category> categories = new ArrayList<Category>();
categories.add(new Category("Food", R.drawable.food_icon, false));
categories.add(new Category("Theater", R.drawable.theater_icon, false));
categories.add(new Category("Places", R.drawable.place_icon, false));
categories.add(new Category("Games", R.drawable.game_icon, false));
categories.add(new Category("Food", R.drawable.food_icon, false));
categories.add(new Category("Games", R.drawable.game_icon, false));
categories.add(new Category("Food", R.drawable.food_icon, false));
categories.add(new Category("Theater", R.drawable.theater_icon, false));
categories.add(new Category("Places", R.drawable.place_icon, false));
categories.add(new Category("Games", R.drawable.game_icon, false));
categories.add(new Category("Food", R.drawable.food_icon, false));
categories.add(new Category("Games", R.drawable.game_icon, false));
categories.add(new Category("Food", R.drawable.food_icon, false));
categories.add(new Category("Theater", R.drawable.theater_icon, false));
categories.add(new Category("Places", R.drawable.place_icon, false));
categories.add(new Category("Games", R.drawable.game_icon, false));
categories.add(new Category("Food", R.drawable.food_icon, false));
categories.add(new Category("Games", R.drawable.game_icon, false));
// Create an {@link WordAdapter}, whose data source is a list of {@link Word}s. The
// adapter knows how to create list items for each item in the list.
final CategoryAdapter adapter = new CategoryAdapter(this, categories);
// Find the {@link ListView} object in the view hierarchy of the {@link Activity}.
// There should be a {@link ListView} with the view ID called list, which is declared in the
// word_list.xml layout file.
ListView listView = (ListView) findViewById(R.id.list);
//Code for adding footer to listView where list ends. Show's button at the end for next screen
//---Strats here-----
LayoutInflater inflater = getLayoutInflater();
ViewGroup footer = (ViewGroup) inflater.inflate(R.layout.footer_categories_button, listView, false);
listView.addFooterView(footer, null, true);
//---Ends here------
// Make the {@link ListView} use the {@link WordAdapter} we created above, so that the
// {@link ListView} will display list items for each {@link Word} in the list.
//// listView.setAdapter(adapter);
}
}
category_list.xml
<?xml version="1.0" encoding="utf-8"?>
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/list"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="60dp"
android:orientation="horizontal"
android:minHeight="60dp">
<ImageView
android:layout_width="88dp"
android:layout_height="88dp"
android:id="@+id/image" />
<LinearLayout
android:id="@+id/text_container"
android:layout_width="match_parent"
android:layout_height="60dp"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:orientation="vertical"
android:paddingLeft="16dp"
android:layout_toRightOf="@+id/image">
<TextView
android:id="@+id/categoryNames"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="1"
tools:text="Food"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="#000000"
android:textStyle="bold"
android:gravity="center" />
</LinearLayout>
<CheckBox
android:layout_width="48dp"
android:layout_height="48dp"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginRight="16dp"
android:id="@+id/checkbox"
/>
</RelativeLayout>
答案 0 :(得分：0)
@Override
public View getView(int position, View convertView, ViewGroup parent) {
/* Some need code here */
CheckBox checkBox = (CheckBox) listItemView.findViewById(R.id.checkbox);
checkBox.setChecked(currentCategory.getIsChecked());
checkBox.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
if(isChecked){
currentCategory.setIsChecked(true)
}else{
currentCategory.setIsChecked(false)
}
}
}
);
return listItemView;
}
答案 1 :(得分：0)
经过长时间的长时间搜索后，我找到了关于vogella的答案。这些人很棒。如果我说我搜索了很多教程，我没有错。最后，沃格拉终于帮助了我。
CategoryAdapter.java
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.ImageView;
import android.widget.TextView;
public class CategoryAdapter extends ArrayAdapter<Category> {
private final ArrayList<Category> list;
private final Activity context;
public CategoryAdapter(Activity context, ArrayList<Category> list) {
super(context, R.layout.list_item, list);
this.context = context;
this.list = list;
}
static class ViewHolder {
protected ImageView imageView;
protected TextView text;
protected CheckBox checkbox;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = null;
if (convertView == null) {
LayoutInflater inflator = context.getLayoutInflater();
view = inflator.inflate(R.layout.list_item, null);
final ViewHolder viewHolder = new ViewHolder();
viewHolder.imageView = (ImageView) view.findViewById(R.id.image);
viewHolder.text = (TextView) view.findViewById(R.id.categoryNames);
viewHolder.checkbox = (CheckBox) view.findViewById(R.id.checkbox);
viewHolder.checkbox
.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
Category element = (Category) viewHolder.checkbox
.getTag();
element.setIsChecked(buttonView.isChecked());
}
});
view.setTag(viewHolder);
viewHolder.checkbox.setTag(list.get(position));
} else {
view = convertView;
((ViewHolder) view.getTag()).checkbox.setTag(list.get(position));
}
ViewHolder holder = (ViewHolder) view.getTag();
holder.imageView.setImageResource(list.get(position).getImageResourceId());
holder.text.setText(list.get(position).getCategoryName());
holder.checkbox.setChecked(list.get(position).getIsChecked());
return view;
}
}