• 搜索关键词自动完成列表，尚未完成。

activity_search.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_search"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@color/gray_background"
    tools:context="com.ttt.zhihudaily.activity.SearchActivity">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar_search_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <include
            android:id="@+id/toolbar_search"
            layout="@layout/toolbar_search" />

    </android.support.design.widget.AppBarLayout>
    <TextView
        android:id="@+id/search_fail_text"
        android:visibility="gone"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:gravity="center"
        android:background="@color/gray_background"
        android:text="未搜索到结果"
        android:textSize="16sp"
        android:textColor="@color/text"/>
    <ListView
        android:id="@+id/list_view_search"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="6dp"
        android:layout_marginRight="6dp"
        android:footerDividersEnabled="false"
        android:background="@color/gray_background"/>

</LinearLayout>

toolbar_search.xml：

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimary"
    android:minHeight="?attr/actionBarSize"
    app:contentInsetLeft="0dp"
    app:contentInsetStart="0dp"
    app:layout_scrollFlags="scroll|enterAlways"
    app:theme="@style/MyToolbarTheme">
    <!--app:contentInsetStart="0dp" app:contentInsetLeft="0dp" 防止内部布局左边有留白-->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:gravity="center_vertical">
        <LinearLayout
            android:layout_width="0dp"
            android:layout_weight="5"
            android:layout_height="30dp"
            android:background="@drawable/search_selector_search"
            android:orientation="horizontal">
            <ImageView
                android:layout_width="22dp"
                android:layout_height="22dp"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="7dp"
                android:src="@drawable/search"/>
            <EditText
                android:id="@+id/search_edit_text"
                android:layout_width="170dp"
                android:layout_height="match_parent"
                android:layout_marginLeft="3dp"
                android:imeOptions="actionSearch"
                android:inputType="text"
                android:background="@null"
                android:hint="@string/search_hint"
                android:textColor="@color/white"
                android:textColorHint="@color/gray_pressed"
                android:maxLines="1"
                android:textSize="16sp" />
            <!--将软键盘Enter变为搜索：android:imeOptions="actionSearch" android:inputType="text"-->
            <ImageView
                android:id="@+id/search_cancel"
                android:visibility="gone"
                android:layout_width="16dp"
                android:layout_height="16dp"
                android:layout_gravity="center_vertical"
                android:src="@drawable/search_cancel"/>

        </LinearLayout>
        <ImageView
            android:id="@+id/search_start"
            android:padding="5dp"
            android:layout_marginRight="5dp"
            android:visibility="gone"
            android:layout_width="42dp"
            android:layout_height="42dp"
            android:background="@drawable/search_start_selector"
            android:src="@drawable/search"/>
    </LinearLayout>

</android.support.v7.widget.Toolbar>

serach_history_list_view_item.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center_vertical"
    android:paddingLeft="10dp"
    android:paddingRight="10dp">

    <ImageView
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="20dp"
        android:src="@drawable/search_history"/>

    <TextView
        android:id="@+id/search_history_text"
        android:layout_width="0dp"
        android:layout_weight="8"
        android:layout_height="50dp"
        android:gravity="center_vertical"
        android:layout_marginLeft="5dp"
        android:textSize="15sp"
        android:layout_gravity="center_vertical"
        android:textColor="@color/gray_search_history"/>

    <ImageView
        android:id="@+id/search_history_delete"
        android:padding="6dp"
        android:layout_width="27dp"
        android:layout_height="27dp"
        android:background="@drawable/delete_search_selector"
        android:src="@drawable/search_history_delete"/>

</LinearLayout>

list_view_footer.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/footer_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="@color/gray_shadow"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:gravity="center"
        android:text="清空搜索记录"
        android:textColor="@color/red_exit" />
</LinearLayout>

SearchActivity：

public class SearchActivity extends AppCompatActivity implements View.OnClickListener {

    private Toolbar toolbar;
    private DBUtil mDBUtil;
    private ImageView searchCancel;
    private EditText editText;
    private ImageView searchStart;
    private MyListAdapter titleAdapter;
    private MySearchHistoryListAdapter historyAdapter;
    private ListView listView;
    private TextView textFail;
    private List<Title> titleList;
    private List<String> historyList;
    private String[] autoCompleteList = {"自", "动", "完", "成", "列", "表"};
    private Drawable divider;
    private View footerView;
    private InputMethodManager imm;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_search);
        toolbar = (Toolbar) findViewById(R.id.toolbar_search);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        init();
        setEditText();

        showHistoryList();
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                finish();
                break;
            default:
                break;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.search_start:
                search();
                // 隐藏软键盘
                imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);
                break;
            case R.id.search_cancel:
                editText.setText("");
                // 重新打开软键盘
                imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS);
                break;
            default:
                break;
        }
    }

    private void init() {
        editText = (EditText) findViewById(R.id.search_edit_text);
        searchCancel = (ImageView) findViewById(R.id.search_cancel);
        searchStart = (ImageView) findViewById(R.id.search_start);
        textFail = (TextView) findViewById(R.id.search_fail_text);
        listView = (ListView) findViewById(R.id.list_view_search);

        searchCancel.setOnClickListener(this);
        searchStart.setOnClickListener(this);

        titleList = new ArrayList<>();
        historyList = new ArrayList<>();
        titleAdapter = new MyListAdapter(this, R.layout.list_view_item, titleList);
        footerView = LayoutInflater.from(this).inflate(R.layout.list_view_footer, null);
        historyAdapter = new MySearchHistoryListAdapter(this, R.layout.serach_history_list_view_item, historyList);
        // 点叉叉删除搜索记录后，重新显示列表
        historyAdapter.setDeleteHistoryListener(new MySearchHistoryListAdapter.DeleteHistoryListener() {
            @Override
            public void onDeleteFinish() {
                historyList.clear();
                historyList.addAll(mDBUtil.loadSearchHistory());
                Collections.reverse(historyList);
                if (historyList.size() == 0) {
                    listView.removeFooterView(footerView);
                }
                historyAdapter.notifyDataSetChanged();
            }
        });

        imm = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
    }

    private void setEditText() {
        // 设置按下软键盘Enter键执行搜索
        editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                if(actionId==EditorInfo.IME_ACTION_SEARCH){
                    imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);
                    search();
                }
                return true;
            }
        });

        // 监听EditText输入内容变化
        editText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                textFail.setVisibility(View.GONE);
                if (!"".equals(s.toString())) {
                    searchCancel.setVisibility(View.VISIBLE);
                    searchStart.setVisibility(View.VISIBLE);
                    showAutoCompleteList();
                } else {
                    searchCancel.setVisibility(View.GONE);
                    searchStart.setVisibility(View.GONE);
                    showHistoryList();
                }
            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });
    }

    // 执行搜索
    private void search() {
        String key = editText.getText().toString();
        if (!key.equals("")) {
            if (mDBUtil.isExistInSearch(key)) {
                mDBUtil.deleteSearchHistory(key);
            }
            mDBUtil.saveSearchHistory(key);
            titleList.clear();
            titleList.addAll(mDBUtil.searchNewsTitle(key));
            showTitleList();
            if (titleList.size() == 0) {
                textFail.setVisibility(View.VISIBLE);
            }
        }
    }

    // 显示搜索结果列表
    private void showTitleList() {
        listView.setDivider(null);
        if (footerView != null) {
            listView.removeFooterView(footerView);
        }
        listView.setAdapter(titleAdapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
                if (HttpUtil.isNetworkConnected(SearchActivity.this)) {
                    NewsActivity.startNewsActivity(SearchActivity.this, titleAdapter.getItem(position));
                } else {
                    Snackbar.make(listView, "没有网络", Snackbar.LENGTH_SHORT).show();
                }
            }
        });
    }

    // 显示搜索历史列表
    private void showHistoryList() {
        if (divider == null) {
            divider = listView.getDivider();
        }
        mDBUtil = DBUtil.getInstance(this);
        historyList.clear();
        historyList.addAll(mDBUtil.loadSearchHistory());
        Collections.reverse(historyList);
        listView.setDivider(divider);
        if (listView.getFooterViewsCount() == 0 && historyList.size() != 0) {
            // 增加“清除搜索记录”页脚
            listView.addFooterView(footerView, null, true);
        }
        listView.setAdapter(historyAdapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
                // 点击最后一项清除搜索记录
                if (position == historyList.size()) {
                    AlertDialog.Builder dialog = new AlertDialog.Builder(SearchActivity.this);
                    dialog.setMessage("确定删除所有搜索记录？");
                    dialog.setCancelable(true);
                    dialog.setPositiveButton("删除", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            mDBUtil.deleteAllSearchHistory();
                            historyList.clear();
                            historyAdapter.notifyDataSetChanged();
                            listView.removeFooterView(footerView);
                        }
                    });
                    dialog.setNegativeButton("取消", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                        }
                    });
                    dialog.show();
                } else {
                    // 把关键词放入EditText，并执行搜索
                    editText.setText(historyAdapter.getItem(position));
                    search();
                }
            }
        });
    }

    // 显示自动完成列表
    private void showAutoCompleteList() {
        listView.setDivider(divider);
        if (footerView != null) {
            listView.removeFooterView(footerView);
        }
        listView.setAdapter(new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, autoCompleteList));
    }

    // 触碰屏幕就关闭软键盘
    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        InputMethodManager imm = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
        imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);
        return super.dispatchTouchEvent(ev);
    }
}

MyListAdapter：

public class MyListAdapter extends ArrayAdapter<Title>{

    private int resource;
    private Context mContext;

    public MyListAdapter(Context context, int resource, List<Title> objects){
        super(context,resource,objects);
        this.resource=resource;
        mContext=context;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        View view;
        Title title = getItem(position);
        if (convertView == null) {
            view = LayoutInflater.from(getContext()).inflate(resource, null);
            viewHolder =new ViewHolder();
            viewHolder.imageView=(ImageView)view.findViewById(R.id.list_title_image);
            viewHolder.textView=(TextView)view.findViewById(R.id.list_title_text);
            view.setTag(viewHolder);
        }else {
            view=convertView;
            viewHolder=(ViewHolder) view.getTag();
        }
        viewHolder.textView.setText(title.getName());
        Glide.with(mContext).load(title.getImage()).placeholder(R.drawable.loading_image)
                .error(R.drawable.fail_image).into(viewHolder.imageView);
        return view;
    }

    private class ViewHolder{
        private ImageView imageView;
        private TextView textView;
    }
}

MySearchHistoryListAdapter：

public class MySearchHistoryListAdapter extends ArrayAdapter<String>{

    private int resource;
    private Context context;
    private DeleteHistoryListener listener;

    public MySearchHistoryListAdapter(Context context, int resource, List<String> objects){
        super(context,resource,objects);
        this.resource=resource;
        this.context=context;
    }

    public void setDeleteHistoryListener(DeleteHistoryListener listener){
        this.listener=listener;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        View view;
        final String key = getItem(position);
        if (convertView == null) {
            view = LayoutInflater.from(getContext()).inflate(resource, null);
            viewHolder =new ViewHolder();
            viewHolder.imageView=(ImageView)view.findViewById(R.id.search_history_delete);
            viewHolder.textView=(TextView)view.findViewById(R.id.search_history_text);
            view.setTag(viewHolder);
        }else {
            view=convertView;
            viewHolder=(ViewHolder) view.getTag();
        }
        viewHolder.textView.setText(key);
        // 点叉叉删除对应搜索记录
        viewHolder.imageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DBUtil.getInstance(context).deleteSearchHistory(key);
                if (listener!=null){
                    listener.onDeleteFinish();
                }
            }
        });
        return view;
    }

    private class ViewHolder{
        private ImageView imageView;
        private TextView textView;
    }

    public interface DeleteHistoryListener{
        void onDeleteFinish();
    }
}