java - Android:检查一个复选框会检查同一行中的所有复选框

Question

我的应用程序显示 ListView具有不同数量的CheckBoxes对于每个 row 。最大数量CheckBoxes一行是三。我的应用程序如下所示:

1. 如果左边CheckBox全部被检查CheckBoxes右侧应该会自动检查。
2. 如果正确CheckBox全部未经检查CheckBoxes左侧应该会自动取消选中。

我在这里举一个小例子:
有三个CheckBoxes (cb1, cb2 and cb3)在第一行。 cb1在左侧，cb2在中间和 cb3在右侧。

1. 全部 CheckBoxes目前尚未检查。用户检查左侧( cb1 )。所有其他CheckBoxes (cb2 and cb3)会被自动检查。
2. 全部 CheckBoxes目前正在检查中。用户取消选中右侧的一项 ( cb3 )。所有其他CheckBoxes (cb1 and cb2)会自动取消选中。

我尝试用 OnCheckedChangeListener 解决我的问题，但出现以下消息

"Variable 'Holder' is accessed from within the inner class, needs to be declared final."

我的问题:

1. 如何解决这个问题，以免出现消息？

2. 我的解决方案在逻辑上正确吗？

如果我的问题不清楚，请发表评论。

我的解决方案:

 holder.cb1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                 @Override
                 public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                     buttonView.setChecked(isChecked);
                     //Case1: Left (cb1) gets checked -> set all other right CB´s (cb2 & cb3) checked
                     if(isChecked){
                         holder.cb2.setChecked(isChecked);  //Error Message occurs here
                         holder.cb3.setChecked(isChecked);  //Error Message occurs here
                     }
                   }
               });

            holder.cb2.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    buttonView.setChecked(isChecked);
                    //Case2: Middle (cb2) gets checked -> set right CB (cb3) checked
                    if(isChecked){
                        holder.cb3.setChecked(isChecked);   //Error Message occurs here
                    }
                    //Case3: Middle (cb2) gets unchecked -> set left CB (cb1) unchecked
                    else {
                        holder.cb1.setChecked(isChecked);   //Error Message occurs here
                    }
                  }
              });

            holder.cb3.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    buttonView.setChecked(isChecked);
                    //Case4: Right (cb3) gets unchecked -> set all other left CB´s (cb1 & cb 2) unchecked
                    if(!isChecked){
                        holder.cb2.setChecked(isChecked);   //Error Message occurs here
                        holder.cb1.setChecked(isChecked);   //Error Message occurs here
                    }
                  }
              });

自定义适配器:

public class ItemListAdapter extends BaseAdapter {

private LayoutInflater inflater;
private ArrayList<Object> itemArray;
int resIdImage;
private static final int TYPE_ListElement = 0;
private static final int TYPE_DIVIDER = 1;

public ItemListAdapter(Context context, ArrayList<Object> itemArray, int resource) {
    this.itemArray = itemArray;
    this.resIdImage = resource;
    this.inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public int getCount() {
    return itemArray.size();
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public Object getItem(int position) {
    return itemArray.get(position);
}

@Override
public int getViewTypeCount() {
    // TYPE_PERSON and TYPE_DIVIDER
    return 2;
}

@Override
public int getItemViewType(int position) {
    if (getItem(position) instanceof ItemList) {
        return TYPE_ListElement;
    }

    return TYPE_DIVIDER;
}

@Override
public boolean isEnabled(int position) {
    return (getItemViewType(position) == TYPE_ListElement);
}

public class DataHolder{
    ImageView imageView;
    TextView textView;
    CheckBox cb1;
    CheckBox cb2;
    CheckBox cb3;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {

    DataHolder holder =  null;
    int type = getItemViewType(position);
    if (convertView == null) {
        switch (type) {
            case TYPE_ListElement:
                convertView = inflater.inflate(resIdImage, parent, false);
                holder = new DataHolder();
                holder.imageView = (ImageView) convertView.findViewById(R.id.image);
                holder.textView = (TextView) convertView.findViewById(R.id.nameLabel);
                holder.cb1 = (CheckBox) convertView.findViewById(R.id.checkbox);
                holder.cb2 = (CheckBox) convertView.findViewById(R.id.checkbox2);
                holder.cb3 = (CheckBox) convertView.findViewById(R.id.checkbox3);
                convertView.setTag(holder);
                break;
            case TYPE_DIVIDER:
                convertView = inflater.inflate(R.layout.row_header, parent, false);
                break;
        }
    }
    else {
        holder = (DataHolder)convertView.getTag();
    }

    switch (type) {
        case TYPE_ListElement:
            ItemList item = (ItemList) getItem(position);
            holder.textView.setText(item.getTitle());
            holder.imageView.setImageResource(item.resIdImage);

            int numCheckBox = item.numCheckBox;
            if(numCheckBox == 1){
               holder.cb1.setVisibility(View.VISIBLE);
               holder.cb2.setVisibility(View.GONE);
               holder.cb3.setVisibility(View.GONE);
            } else if (numCheckBox == 2){
               holder.cb1.setVisibility(View.VISIBLE);
               holder.cb2.setVisibility(View.VISIBLE);
               holder.cb3.setVisibility(View.GONE);
            } else if (numCheckBox == 3){
               holder.cb1.setVisibility(View.VISIBLE);
               holder.cb2.setVisibility(View.VISIBLE);
               holder.cb3.setVisibility(View.VISIBLE);
            }
             holder.cb1.setChecked(item.checked);
             holder.cb2.setChecked(item.checked);
             holder.cb3.setChecked(item.checked);

             holder.cb1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                 @Override
                 public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                     buttonView.setChecked(isChecked);
                     //Case1: Left (cb1) gets checked -> set all other right CB´s (cb2 & cb3) checked
                     if(isChecked){
                         holder.cb2.setChecked(isChecked);  //Error Message occurs here
                         holder.cb3.setChecked(isChecked);  //Error Message occurs here
                     }
                 }
             });

            holder.cb2.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    buttonView.setChecked(isChecked);
                    //Case2: Middle (cb2) gets checked -> set right CB (cb3) checked
                    if(isChecked){
                        holder.cb3.setChecked(isChecked);   //Error Message occurs here
                    }
                    //Case3: Middle (cb2) gets unchecked -> set left CB (cb1) unchecked
                    else {
                        holder.cb1.setChecked(isChecked);   //Error Message occurs here
                    }
                }
            });

            holder.cb3.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    buttonView.setChecked(isChecked);
                    //Case4: Right (cb3) gets unchecked -> set all other left CB´s (cb1 & cb 2) unchecked
                    if(!isChecked){
                        holder.cb2.setChecked(isChecked);   //Error Message occurs here
                        holder.cb1.setChecked(isChecked);   //Error Message occurs here
                    }
                }
            });

             break;

        case TYPE_DIVIDER:
            TextView title = (TextView)convertView.findViewById(R.id.headerTitle);
            String titleString = (String)getItem(position);
            title.setText(titleString);
            break;
    }


    return convertView;
}
}

行布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<ImageView
    android:id="@+id/image"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:srcCompat="@mipmap/ic_launcher"
    android:layout_gravity="center"
    android:layout_margin="20dp"/>

<TextView
    android:id="@+id/nameLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="20sp"
    android:layout_margin="20dp"
    android:text="Name"
    android:layout_weight="1"
/>

<CheckBox
    android:id="@+id/checkbox"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:checked="false"
    android:focusable="false"
    android:focusableInTouchMode="false"
    android:layout_gravity="right|center"
    android:gravity="right|center"
    />

<CheckBox
    android:id="@+id/checkbox2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:checked="false"
    android:focusable="false"
    android:focusableInTouchMode="false"
    android:layout_gravity="right|center"
    android:gravity="right|center"
    />

<CheckBox
    android:id="@+id/checkbox3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:checked="false"
    android:focusable="false"
    android:focusableInTouchMode="false"
    android:layout_gravity="right|center"
    android:gravity="right|center"
    />

</LinearLayout>

Answer 1

创建一个引用您的ViewHolder的final变量，并在onCheckedChangeListener中使用它:

final DataHolder finalHolder = holder;

holder.cb1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                 buttonView.setChecked(isChecked);
                 //Case1: Left (cb1) gets checked -> set all other right CB´s (cb2 & cb3) checked
                 if(isChecked){
                     finalHolder.cb2.setChecked(isChecked);  // NO MORE ERROR
                     finalHolder.cb3.setChecked(isChecked);  //NO MORE ERROR
                 }
             }
         });

holder.cb2.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                buttonView.setChecked(isChecked);
                //Case2: Middle (cb2) gets checked -> set right CB (cb3) checked
                if(isChecked){
                    finalHolder.cb3.setChecked(isChecked);   // NO MORE ERROR
                }
                //Case3: Middle (cb2) gets unchecked -> set left CB (cb1) unchecked
                else {
                    finalHolder.cb1.setChecked(isChecked);   //NO MORE ERROR
                }
            }
        });

Do the same for cb3 onCheckedChangeListener as well.