1.在string.xml中添加下列语句

<string name="del_crime">删除陋习</string>

2.修改list_item_crime.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="wrap_content">
    <Button
        android:id="@+id/list_item_crime_delete_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:text="@string/del_crime"/>
    <CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/list_item_crime_solved_check_box"
        android:layout_centerVertical="true"
        android:layout_toLeftOf="@+id/list_item_crime_delete_button"
        android:padding="4dp"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/list_item_crime_title_text_view"
        android:layout_toLeftOf="@+id/list_item_crime_solved_check_box"
        android:textStyle="bold"
        android:padding="4dp"
        tools:text="Crime Title"
        />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/list_item_crime_date_text_view"
        android:layout_toLeftOf="@+id/list_item_crime_solved_check_box"
        android:layout_below="@+id/list_item_crime_title_text_view"
        android:padding="4dp"
        tools:text="Crime Date"
        />
</RelativeLayout>

3.在CrimeListFragment.java的CrimeHolder中添加下列语句

private class CrimeHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
        ...
        private Button mDeleteButton;

        public CrimeHolder(View itemView){
            ...
            mDeleteButton=(Button)itemView.findViewById(R.id.list_item_crime_delete_button);
        }
        public void bindCrime(Crime crime){
            ...
            mDeleteButton.setOnClickListener(new View.OnClickListener(){
                @Override
                public void onClick(View view){
                    AlertDialog.Builder builder=new AlertDialog.Builder(getActivity());
                    builder.setMessage("确认要删除陋习"+mCrime.getTitle()+"?")
                            .setPositiveButton("确认", new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialogPreference,int position){
                                    CrimeLab.get(getActivity()).delCrime(mCrime);
                                    mAdapter.notifyDataSetChanged();
                                }
                            }).setNegativeButton("取消",null)
                            .create().show();
                }
            });
        }
        ...
    }

4.在CrimeLab.java中添加下列语句

public void delCrime(Crime c){
        String uuidString=c.getId().toString();
        mDatabase.delete(CrimeTable.NAME,CrimeTable.Cols.UUID+ " = ?",new String[]{uuidString});
    }

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