Android自带emoji表情的使用方法详解

2020-10-22 14:48:30 浏览数 (1)

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:”ud83dude01”,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 “ud83dude00” – “ud83cudf7c”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:

代码语言：javascript复制
/**
* 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("rn");
 }
 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:

代码语言：javascript复制
/**
* 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

代码语言：javascript复制
<?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:

代码语言：javascript复制
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()   "rn");
 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

代码语言：javascript复制
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("rn");
}
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

代码语言：javascript复制
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;
}
}

以上就是本文的全部内容，希望对大家的学习有所帮助。

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