写一个基于安卓studio的图书信息管理系统，实现增删改查

好的，以下是一个基于安卓Studio的图书信息管理系统的代码实现，包括增删改查功能：

首先，在布局文件中定义UI界面，如下所示（我这里使用了RecyclerView来展示图书信息）：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 
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=".MainActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingTop="16dp"
        android:paddingBottom="16dp"/>

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fab_add_book"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:src="@drawable/ic_add_black_24dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

接着，在MainActivity中定义RecyclerView的Adapter和ViewHolder，如下所示：

public class BookAdapter extends RecyclerView.Adapter<BookAdapter.BookViewHolder> {

    private List<Book> bookList;
    private OnItemClickListener listener;

    public interface OnItemClickListener {
        void onItemClick(int position);
    }

    public void setOnItemClickListener(OnItemClickListener listener) {
        this.listener = listener;
    }

    static class BookViewHolder extends RecyclerView.ViewHolder {
        TextView tvTitle, tvAuthor, tvISBN;

        BookViewHolder(@NonNull View itemView, final OnItemClickListener listener) {
            super(itemView);
            tvTitle = itemView.findViewById(R.id.tv_title);
            tvAuthor = itemView.findViewById(R.id.tv_author);
            tvISBN = itemView.findViewById(R.id.tv_isbn);

            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if (listener != null) {
                        int position = getAdapterPosition();
                        if (position != RecyclerView.NO_POSITION) {
                            listener.onItemClick(position);
                        }
                    }
                }
            });
        }
    }

    public BookAdapter(List<Book> bookList) {
        this.bookList = bookList;
    }

    @NonNull
    @Override
    public BookViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.book_item, parent, false);
        return new BookViewHolder(itemView, listener);
    }

    @Override
    public void onBindViewHolder(@NonNull BookViewHolder holder, int position) {
        Book book = bookList.get(position);
        holder.tvTitle.setText(book.getTitle());
        holder.tvAuthor.setText(book.getAuthor());
        holder.tvISBN.setText(book.getISBN());
    }

    @Override
    public int getItemCount() {
        return bookList.size();
    }
}

定义Book实体类，如下所示：

public class Book {
    private String title;
    private String author;
    private String ISBN;

    public Book(String title, String author, String ISBN) {
        this.title = title;
        this.author = author;
        this.ISBN = ISBN;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public String getISBN() {
        return ISBN;
    }

    public void setISBN(String ISBN) {
        this.ISBN = ISBN;
    }
}

在MainActivity中，定义一个Book列表和一个BookAdapter的实例：

public class MainActivity extends AppCompatActivity {

    private List<Book> bookList = new ArrayList<>();
    private BookAdapter bookAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        RecyclerView recyclerView = findViewById(R.id.recycler_view);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        bookAdapter = new BookAdapter(bookList);
        recyclerView.setAdapter(bookAdapter);

        bookAdapter.setOnItemClickListener(new BookAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(int position) {
                // TODO: 点击事件处理
            }
        });

        FloatingActionButton fabAddBook = findViewById(R.id.fab_add_book);
        fabAddBook.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // TODO: 添加图书操作
            }
        });
    }
}

接下来，实现图书信息的增删改查功能：

添加图书：

private void addBook() {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("添加图书");

    View view = LayoutInflater.from(this).inflate(R.layout.dialog_add_book, null);
    final EditText etTitle = view.findViewById(R.id.et_title);
    final EditText etAuthor = view.findViewById(R.id.et_author);
    final EditText etISBN = view.findViewById(R.id.et_isbn);
    builder.setView(view);

    builder.setPositiveButton("添加", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialogInterface, int i) {
            String title = etTitle.getText().toString();
            String author = etAuthor.getText().toString();
            String ISBN = etISBN.getText().toString();
            Book book = new Book(title, author, ISBN);
            bookList.add(book);
            bookAdapter.notifyItemInserted(bookList.size() - 1);
        }
    });

    builder.setNegativeButton("取消", null);

    builder.show();
}

修改图书：

private void editBook(final int position) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("修改图书");

    View view = LayoutInflater.from(this).inflate(R.layout.dialog_add_book, null);
    final EditText etTitle = view.findViewById(R.id.et_title);
    final EditText etAuthor = view.findViewById(R.id.et_author);
    final EditText etISBN = view.findViewById(R.id.et_isbn);
    Book book = bookList.get(position);
    etTitle.setText(book.getTitle());
    etAuthor.setText(book.getAuthor());
    etISBN.setText(book.getISBN());
    builder.setView(view);

    builder.setPositiveButton("修改", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialogInterface, int i) {
            String title = etTitle.getText().toString();
            String author = etAuthor.getText().toString();
            String ISBN = etISBN.getText().toString();
            Book book = bookList.get(position);
            book.setTitle(title);
            book.setAuthor(author);
            book.setISBN(ISBN);
            bookAdapter.notifyItemChanged(position);
        }
    });

    builder.setNegativeButton("取消", null);

    builder.show();
}

删除图书：

private void deleteBook(final int position) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("删除图书");
    builder.setMessage("确定要删除这本图书吗？");

    builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialogInterface, int i) {
            bookList.remove(position);
            bookAdapter.notifyItemRemoved(position);
        }
    });

    builder.setNegativeButton("取消", null);

    builder.show();
}

查询图书：

private void searchBook() {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("查询图书");

    View view = LayoutInflater.from(this).inflate(R.layout.dialog_search_book, null);
    final EditText etKeyword = view.findViewById(R.id.et_keyword);
    builder.setView(view);

    builder.setPositiveButton("查询", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialogInterface, int i) {
            String keyword = etKeyword.getText().toString();
            List<Book> searchResult = new ArrayList<>();
            for (Book book : bookList) {
                if (book.getTitle().contains(keyword) || book.getAuthor().contains(keyword)
                        || book.getISBN().contains(keyword)) {
                    searchResult.add(book);
                }
            }
            if (searchResult.size() > 0) {
                bookList.clear();
                bookList.addAll(searchResult);
                bookAdapter.notifyDataSetChanged();
            } else {
                Toast.makeText(MainActivity.this, "未找到匹配的图书！", Toast.LENGTH_SHORT).show();
            }
        }
    });

    builder.setNegativeButton("取消", null);

    builder.show();
}

最后，在MainActivity中，将增删改查操作绑定到UI界面上，如下所示：

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    switch (id) {
        case R.id.action_add:
            addBook();
            return true;
        case R.id.action_search:
            searchBook();
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

@Override
public void onItemClick(int position) {
    final int clickedPosition = position;
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("选择操作");

    String[] options = {"修改", "删除"};
    builder.setItems(options, new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialogInterface, int i) {
            switch (i) {
                case 0:
                    editBook(clickedPosition);
                    break;
                case 1:
                    deleteBook(clickedPosition);
                    break;
            }
        }
    });

    builder.show();
}

这样，一个基于安卓Studio的图书信息管理系统就完成了。