Android自带emoji表情的使用方法详解

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<View> getPagerList() {
 List<View> 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

<?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:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical"
 >
 <!--显示表情的TextView-->
 <TextView
 android:id="@+id/tv_info"
 android:layout_width="match_parent"
 android:layout_height="0dp"
 android:layout_weight="1"
 android:padding="15dp"
 />
 <!--表情,输入框,发送-->
 <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>
 <!--表情面板-->
 <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<View> 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<View> getPagerList() {
 List<View> 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;
 }

}

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