Android 利用正则+反射+SpannableString展示Emoji表情

Android 利用正则+反射+SpannableString展示Emoji表情

简单实现一下，仅供参考，先给一张图片~~

• 先说下实现的步骤
• 1.从输入的字符串中获取匹配emoji表情名称的子字符串
• 2.利用R.mipmap.class来找到该emoji名称对应的Rid
• 3.利用Rid获取到对应的Drawable
• 4.emoji Drawable转换成ImageSpan
• 5.将原字符串转换成SpannableString,并在读取到的Emoji位置把ImageSpan替换上去
• 6显示在TextView上即可

---

• 1将众多emoji表情导入mipmap文件夹下，并且名称为“emoxxx”
• 2.布局如下，TextView 和EditText

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="16sp"/>

    <EditText
        android:id="@+id/et"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:inputType="text"/>
LinearLayout>

• 3.代码如下

public class MainActivity extends AppCompatActivity implements TextWatcher {

    private TextView tv;
    private EditText et;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
        et = (EditText) findViewById(R.id.et);
        et.addTextChangedListener(this);
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        changeStrWithEmoji(s.toString());
    }

    @Override
    public void afterTextChanged(Editable s) {
    }

    String TAG = "TAG";

    public void changeStrWithEmoji(String input) {
        //1.匹配字符串input中“[xxx]”
        Pattern pattern = Pattern.compile("\\[[^\\[\\]]*\\]");
        //2.获取匹配器
        Matcher matcher = pattern.matcher(input);
        //3.创建SP
        SpannableString sp = new SpannableString(input);
        //4.依次找到字符串input匹配到的子字符串
        while (matcher.find()) {
            //5.获取匹配到的子字符串[emoxxx]
            String group = matcher.group();
            //6.在该字符串开始的位置 与结束的位置
            int start = matcher.start();
            int end = matcher.end();
            Log.d(TAG, group);
            //7.获取 R.mipmap.class 实例
            Class mipmapClass = R.mipmap.class;
            try {
                //8.去掉[emoxxx] 中括号查找 定义的变量
                Field field = mipmapClass.getDeclaredField(group.substring(1, group.length() - 1));
                //9 R.mipmap.class 定义的变量都是 static的 可直接获取
                int rid = field.getInt(null);

                Log.d(TAG, rid + "");
                //10.获取该[emoxxx]对应的emo Drawable
                Drawable drawable = getResources().getDrawable(rid);
                drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
                //11.在指定的位置设置该 ImageSpan即可
                sp.setSpan(new ImageSpan(drawable), start, end, Spannable.SPAN_INCLUSIVE_EXCLUSIVE);

            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        //12.显示出来
        tv.setText(sp);
    }
}

• 完~~