Android studio 做一个新闻发布和查询页面代码

好的，下面是一个简单的新闻发布和查询页面代码：

1. 创建一个新的Android项目，并在布局文件中添加以下代码：

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <EditText
        android:id="@+id/titleEditText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="标题" />

    <EditText
        android:id="@+id/contentEditText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="内容" />

    <Button
        android:id="@+id/submitBtn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="发布" />

    <EditText
        android:id="@+id/searchEditText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="搜索关键字" />

    <Button
        android:id="@+id/searchBtn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="查询" />

    <ListView
        android:id="@+id/newsListView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

2. 在MainActivity中添加以下代码：

public class MainActivity extends AppCompatActivity {

    private EditText titleEditText;
    private EditText contentEditText;
    private Button submitBtn;
    private EditText searchEditText;
    private Button searchBtn;
    private ListView newsListView;

    private List<News> newsList = new ArrayList<>();
    private NewsAdapter newsAdapter;

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

        titleEditText = findViewById(R.id.titleEditText);
        contentEditText = findViewById(R.id.contentEditText);
        submitBtn = findViewById(R.id.submitBtn);
        searchEditText = findViewById(R.id.searchEditText);
        searchBtn = findViewById(R.id.searchBtn);
        newsListView = findViewById(R.id.newsListView);

        // 设置ListView适配器
        newsAdapter = new NewsAdapter(MainActivity.this, newsList);
        newsListView.setAdapter(newsAdapter);

        // 发布新闻
        submitBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String title = titleEditText.getText().toString();
                String content = contentEditText.getText().toString();

                // 将新闻添加到newsList中
                News news = new News(title, content);
                newsList.add(news);

                // 刷新ListView
                newsAdapter.notifyDataSetChanged();

                // 清空输入框
                titleEditText.setText("");
                contentEditText.setText("");
            }
        });

        // 查询新闻
        searchBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String keyword = searchEditText.getText().toString();

                // 根据关键字查询新闻
                List<News> resultList = new ArrayList<>();
                for (News news : newsList) {
                    if (news.getTitle().contains(keyword) || news.getContent().contains(keyword)) {
                        resultList.add(news);
                    }
                }

                // 刷新ListView
                newsAdapter.setData(resultList);
                newsAdapter.notifyDataSetChanged();
            }
        });
    }
}

3. 创建一个News类，用于表示新闻：

public class News {
    private String title;
    private String content;

    public News(String title, String content) {
        this.title = title;
        this.content = content;
    }

    public String getTitle() {
        return title;
    }

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

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }
}

4. 创建一个NewsAdapter类，用于将新闻显示在ListView中：

public class NewsAdapter extends BaseAdapter {

    private Context context;
    private List<News> data;

    public NewsAdapter(Context context, List<News> data) {
        this.context = context;
        this.data = data;
    }

    public void setData(List<News> data) {
        this.data = data;
    }

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

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if (convertView == null) {
            convertView = LayoutInflater.from(context).inflate(R.layout.item_news, parent, false);
            viewHolder = new ViewHolder();
            viewHolder.titleTextView = convertView.findViewById(R.id.titleTextView);
            viewHolder.contentTextView = convertView.findViewById(R.id.contentTextView);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        News news = data.get(position);
        viewHolder.titleTextView.setText(news.getTitle());
        viewHolder.contentTextView.setText(news.getContent());

        return convertView;
    }

    private static class ViewHolder {
        TextView titleTextView;
        TextView contentTextView;
    }
}

5. 在布局文件中添加一个item_news.xml文件，用于表示每个新闻的布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dp">

    <TextView
        android:id="@+id/titleTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/contentTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:textSize="16sp" />

</LinearLayout>

这样就完成了一个简单的新闻发布和查询页面。