Android自带的emoji表情的使用

什么是emoji表情

emoji表情是一种表情符号，在代码中它现在其实是一组遵循Unicode的编码，即每一个表情符号都对应了一个Unicode编码。更进一步说，emoji表情实际上是一组Unicode编码与一组表情描述之间的对应。注意，这里所说的不是表情图片，而是表情描述。那么图片的实现是由谁来负责的呢？图片是由各个系统或者软件针对统一的表情描述来各自实现的，他们都遵循统一的Unicode编码规范。也就是说Unicode编码其所对应的表情描述是统一的，是所有人都要共同遵守的一套标准或者规范，而具体的表情图片则可能因平台的不同而产生差异。

---

首先你得先从网上收集一套emoji的Unicode编码,例如这个网站Emoji Unicode Tables
该网站上面给出了每个emoji表情的图片,描述,Unicode编码的对照表,点击表中每一项emoji可看到如下所示:

红色框框就是我们要的值.在java中的Unicode表示就是:”\ud83d\ude01”,该编码字符可以直接被Android的TextView和EditText控件识别成对应的emoji表情.
本次demo中展示了从 “\ud83d\ude00” - “\ud83c\udf7c”这216个emoji表情.
效果图如下:

关于emoji编码的存放和获取

由于有216个emoji编码字符串,因此我把它整理到一个json数组中,然后保存到assets目录下.
然后获取的话,通过如下代码方式获取:

/**
* 从assets目录下获取所有表情
*
* @return
*/
public String[] getEmojis() {
   BufferedReader br = null;
   String emojis[] = null;
   try {
       InputStream is = mContext.getAssets().open("emoji.json");
       StringBuffer sb = new StringBuffer();
       br = new BufferedReader(new InputStreamReader(is));
       String line = null;
       while (null != (line = br.readLine())) {
           sb.append(line).append("\r\n");
       }
       JSONArray emojiArray = new JSONArray(sb.toString());
       if (null != emojiArray && emojiArray.length() > 0) {
           emojis = new String[emojiArray.length()];
           for (int i = 0; i < emojiArray.length(); i++) {
               emojis[i] = emojiArray.optString(i);
           }
       }
   } catch (Exception e) {
       e.printStackTrace();
   } finally {
       if (null != br) {
           try {
               br.close();
           } catch (IOException e) {
               e.printStackTrace();
           }
       }
   }
   return emojis;
}

表情组设计

通过上面的效果图也可以看得出,216个emoji表情被分成了8组,每组27个emoji+1个删除按钮.
实现这个效果也很简单,就是通过ViewPager来展示每一组emoji,而每一组emoji里面又是一个GridView控件,里面的item就是一个个的TextView.
每一组emoji页面的创建代码如下:

/**
* 获取所有表情GridView页面的集合
*
* @return
*/
public List getPagerList() {
   List pagers = null;
   String[] eachPageEmojis = null;
   if (null != mEmojis && mEmojis.length > 0) {
       pagers = new ArrayList<>();
       int pageCount = mEmojis.length / 27;//共8页表情
       for (int i = 0; i < pageCount; i++) {
           GridView gridView = new GridView(mContext);
           gridView.setNumColumns(7);
           gridView.setSelector(new ColorDrawable(Color.TRANSPARENT));
           gridView.setCacheColorHint(Color.TRANSPARENT);
           gridView.setStretchMode(GridView.STRETCH_COLUMN_WIDTH);
           gridView.setGravity(Gravity.CENTER);
           eachPageEmojis = new String[28];
           //总共216个表情字符,索引变化为:0-26,27-53,54-80,81-107,108-134,135-161,162-188,189-215
           System.arraycopy(mEmojis, i * 27, eachPageEmojis, 0, 27);
           eachPageEmojis[27] = "del";//第28是删除按钮,用特殊字符串表示
           gridView.setAdapter(new EmojiGvAdapter(mContext, eachPageEmojis));
           //点击表情监听
           gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
               @Override
               public void onItemClick(AdapterView parent, View view, int position, long id) {
                   //获取选中的表情字符
                   String emoji = (String) parent.getAdapter().getItem(position);
                   if (null != mEmojiClickListener) {
                       mEmojiClickListener.onClick(emoji);
                   }
               }
           });
           pagers.add(gridView);
       }
   }
   return pagers;
}

MainActivity的布局和代码

主布局是一个垂直的线性布局,大体分2部分,表情面板和上面的视图界面

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
   >
    
    <TextView
        android:id="@+id/tv_info"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:padding="15dp"
        />
    
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <Button
            android:id="@+id/btn_emoji"
            android:layout_width="55dp"
            android:layout_height="wrap_content"
            android:text="表情"/>

        <EditText
            android:id="@+id/edt_msg"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"/>

        <Button
            android:id="@+id/btn_send"
            android:layout_width="55dp"
            android:layout_height="wrap_content"
            android:text="发送"/>
    LinearLayout>
    
    <FrameLayout
        android:id="@+id/fl_emoji"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:visibility="gone"
        >

        <android.support.v4.view.ViewPager
            android:id="@+id/vp_emoji"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingTop="10dp"
            />

        <LinearLayout
            android:id="@+id/ll_point"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom"
            android:layout_marginBottom="10dp"
            android:gravity="center"
            android:orientation="horizontal">LinearLayout>

    FrameLayout>
LinearLayout>

MainActivity代码如下:

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";
    private Button mEmojiBtn, mSendBtn;//表情按钮和发送按钮
    private EditText mMsgEdt;//输入框
    private TextView mInfoTv;//展示界面
    private ViewPager mEmojiVp;//表情ViewPager
    private FrameLayout mEmojiFl;//表情面板
    private LinearLayout mVpPointLl;//表情ViewPager指示器
    //输入法和表情平滑切换的辅助类
    private EmotionKeyboardSwitchHelper mEmotionKeyboardSwitchHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mEmotionKeyboardSwitchHelper = EmotionKeyboardSwitchHelper.with(this);
        initView();
        initListener();
    }

    private void initListener() {
        mSendBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mInfoTv.append(mMsgEdt.getText() + "\r\n");
                mMsgEdt.setText("");
            }
        });
        mEmotionKeyboardSwitchHelper.bind(mInfoTv, mMsgEdt, mEmojiBtn, mEmojiFl);
    }

    private void initView() {
        mEmojiBtn = (Button) findViewById(R.id.btn_emoji);
        mSendBtn = (Button) findViewById(R.id.btn_send);
        mMsgEdt = (EditText) findViewById(R.id.edt_msg);
        mInfoTv = (TextView) findViewById(R.id.tv_info);
        mEmojiVp = (ViewPager) findViewById(R.id.vp_emoji);
        mEmojiFl = (FrameLayout) findViewById(R.id.fl_emoji);
        mVpPointLl = (LinearLayout) findViewById(R.id.ll_point);
        initViewPager();
    }

    /**
     * 设置ViewPager表情
     */
    private void initViewPager() {
        EmojiVpAdapter adapter = new EmojiVpAdapter(this);
        mEmojiVp.setAdapter(adapter);
        //表情点击监听
        adapter.setOnEmojiClickListener(new EmojiVpAdapter.OnEmojiClickListener() {
            @Override
            public void onClick(String emoji) {
                if ("del".equals(emoji)) {
                    //表示点击的是删除按钮
                    KeyEvent event = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DEL);
                    mMsgEdt.onKeyDown(KeyEvent.KEYCODE_DEL, event);
                } else {
                    mMsgEdt.append(emoji);
                }
            }
        });
        mEmojiVp.setCurrentItem(0);
        //关联指示器点
        adapter.setupWithPagerPoint(mEmojiVp, mVpPointLl);
    }


    @Override
    public void onBackPressed() {
        if (mEmotionKeyboardSwitchHelper.onBackPress()) {
            super.onBackPressed();
        }
    }
}

emoji ViewPager

public class EmojiVpAdapter extends PagerAdapter {
    private Context mContext;
    private String[] mEmojis;//216个表情字符
    private List mPagers;//展示的页面
    private OnEmojiClickListener mEmojiClickListener;//表情点击监听接口

    public EmojiVpAdapter(Context ctx) {
        this.mContext = ctx;
        this.mEmojis = getEmojis();
        this.mPagers = getPagerList();

    }

    @Override
    public int getCount() {
        return null == mPagers ? 0 : mPagers.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        View view = mPagers.get(position);
        if (null != view) {
            container.addView(view);
        }
        return view;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView((View) object);
    }

    /**
     * 从assets目录下获取所有表情
     *
     * @return
     */
    public String[] getEmojis() {
        BufferedReader br = null;
        String emojis[] = null;
        try {
            InputStream is = mContext.getAssets().open("emoji.json");
            StringBuffer sb = new StringBuffer();
            br = new BufferedReader(new InputStreamReader(is));
            String line = null;
            while (null != (line = br.readLine())) {
                sb.append(line).append("\r\n");
            }
            JSONArray emojiArray = new JSONArray(sb.toString());
            if (null != emojiArray && emojiArray.length() > 0) {
                emojis = new String[emojiArray.length()];
                for (int i = 0; i < emojiArray.length(); i++) {
                    emojis[i] = emojiArray.optString(i);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (null != br) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return emojis;
    }

    /**
     * 获取所有表情GridView页面的集合
     *
     * @return
     */
    public List getPagerList() {
        List pagers = null;
        String[] eachPageEmojis = null;
        if (null != mEmojis && mEmojis.length > 0) {
            pagers = new ArrayList<>();
            int pageCount = mEmojis.length / 27;//共8页表情
            for (int i = 0; i < pageCount; i++) {
                GridView gridView = new GridView(mContext);
                gridView.setNumColumns(7);
                gridView.setSelector(new ColorDrawable(Color.TRANSPARENT));
                gridView.setCacheColorHint(Color.TRANSPARENT);
                gridView.setStretchMode(GridView.STRETCH_COLUMN_WIDTH);
                gridView.setGravity(Gravity.CENTER);
                eachPageEmojis = new String[28];
                //总共216个表情字符,索引变化为:0-26,27-53,54-80,81-107,108-134,135-161,162-188,189-215
                System.arraycopy(mEmojis, i * 27, eachPageEmojis, 0, 27);
                eachPageEmojis[27] = "del";//第28是删除按钮,用特殊字符串表示
                gridView.setAdapter(new EmojiGvAdapter(mContext, eachPageEmojis));
                //点击表情监听
                gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                    @Override
                    public void onItemClick(AdapterView parent, View view, int position, long id) {
                        //获取选中的表情字符
                        String emoji = (String) parent.getAdapter().getItem(position);
                        if (null != mEmojiClickListener) {
                            mEmojiClickListener.onClick(emoji);
                        }
                    }
                });
                pagers.add(gridView);
            }
        }
        return pagers;
    }

    /**
     * 关联指示器点
     *
     * @param viewPager
     * @param pointLayout
     */
    public void setupWithPagerPoint(ViewPager viewPager, final LinearLayout pointLayout) {
        //初始表情指示器
        int pageCount = getCount();
        for (int i = 0; i < pageCount; i++) {
            ImageView point = new ImageView(mContext);
            point.setImageResource(R.drawable.shape_vp_dot_unselected);
            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(-2, -2);
            params.rightMargin = (int) mContext.getResources().getDimension(R.dimen.dp10);
            if (i == 0) {
                point.setImageResource(R.drawable.shape_vp_dot_selected);
            }
            pointLayout.addView(point, params);
        }
        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                //切换指示器
                if (null != pointLayout && pointLayout.getChildCount() > 0) {
                    for (int i = 0; i < pointLayout.getChildCount(); i++) {
                        ((ImageView) pointLayout.getChildAt(i)).setImageResource(R.drawable.shape_vp_dot_unselected);
                    }
                    ((ImageView) pointLayout.getChildAt(position)).setImageResource(R.drawable.shape_vp_dot_selected);
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }

    /**
     * 表情点击监听器
     */
    public interface OnEmojiClickListener {
        void onClick(String emoji);
    }

    public void setOnEmojiClickListener(OnEmojiClickListener l) {
        this.mEmojiClickListener = l;
    }
}

emoji GridView

public class EmojiGvAdapter extends BaseAdapter {
    private Context mContext;
    private String[] mEmojis;

    public EmojiGvAdapter(Context context, String[] eachPageEmojis) {
        this.mContext = context;
        this.mEmojis = eachPageEmojis;
    }

    @Override
    public int getCount() {
        return null == mEmojis ? 0 : mEmojis.length;
    }

    @Override
    public String getItem(int position) {
        return null == mEmojis ? "" : mEmojis[position];
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        if (null == convertView) {
            holder = new ViewHolder();
            convertView = View.inflate(mContext, R.layout.item_emoji, null);
            holder.emojiTv = (TextView) convertView.findViewById(R.id.tv_emoji);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }
        if (position == 27) {
            //第28个显示删除按钮
            holder.emojiTv.setBackgroundResource(R.drawable.ic_emojis_delete);
            FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) holder.emojiTv.getLayoutParams();
            lp.bottomMargin = (int) mContext.getResources().getDimension(R.dimen.dp12);
        } else {
            holder.emojiTv.setText(getItem(position));
        }
        return convertView;
    }

    private static class ViewHolder {
        private TextView emojiTv;
    }


}

源码下载