简单的自定义edittext，实现一键清除，限制emoji表情

首先创建一个类继承editText实现其构造方法

public MyEditText(Context context) {    this(context,null);}public MyEditText(Context context, AttributeSet attrs) {    super(context, attrs);    this.mContext=context;    init(context);}

在init里做一些准备，设置监听这些监听一个是滑动的监听一个是获取焦点的监听

private void init(Context context) {    drawable = context.getResources().getDrawable(R.mipmap.ic_edit_delete);//调用系统资源获取删除的图标    drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());//绘制在哪个区域    setClearIconVisible(false);    super.setOnTouchListener(this);    super.setOnFocusChangeListener(this);    addTextChangedListener(this);//该方法必须写}

//设置图标什么时候出现

private void setClearIconVisible(boolean visible) {    drawable.setVisible(visible, false);    Drawable[] drawables=getCompoundDrawables();    setCompoundDrawables(drawables[0], drawables[1], visible?drawable:null, drawables[3]);}

/****************************以下是禁止输入表情的代码**************************************/

@Overridepublic void beforeTextChanged(CharSequence s, int start, int count, int after) {    if (!resetText) {        cursorPos = getSelectionEnd();        // 这里用s.toString()而不直接用s是因为如果用s，        // 那么，inputAfterText和s在内存中指向的是同一个地址，s改变了，        // inputAfterText也就改变了，那么表情过滤就失败了        inputAfterText = s.toString();    }}@Overridepublic void onTextChanged(CharSequence s, int start, int before, int count) {    if (isFocused()) {        setClearIconVisible(getText().length()>0);    }    if (!resetText) {        if (count >= 2) {//表情符号的字符长度最小为2           // CharSequence input = s.subSequence(cursorPos, cursorPos + count);//这里有问题，在一些输入法里会报出角标越界的错误

修改如下：

            CharSequence input = s.subSequence(start, start + count);
          if (containsEmoji(input.toString())) {              

                                    resetText = true;                

                      Toast.makeText(mContext, "不支持输入Emoji表情符号", Toast.LENGTH_SHORT).show();  //是表情符号就将文本还原为输入表情符号之前的内容        

                      setText(inputAfterText);               

                   CharSequence text = getText();                

               if (text instanceof Spannable) {                   

                      Spannable spanText = (Spannable)text;   

                       Selection.setSelection(spanText, text.length());               

                     }           

                }       

      }   

           } else {      

       resetText = false;    }}

         @Override

        public void afterTextChanged(Editable s) {

}

        @Override

         public void onFocusChange(View v, boolean hasFocus) {    

                    if (hasFocus) {      

                setClearIconVisible(getText().length()>0);    }    

          else {       

                   setClearIconVisible(false);    }}

         @Override

         public boolean onTouch(View v, MotionEvent event) {   

 if (event.getAction()==MotionEvent.ACTION_UP) {   

     int x= (int) event.getX();      

  if (x>getWidth()-getPaddingRight()-drawable.getIntrinsicWidth() && drawable.isVisible()) {       

     setText("");        }    }    return false;}

    /  ** * 检测是否有emoji表情 * * @param source * @return */

     public static boolean containsEmoji(String source) {    

      int len = source.length();  

       for (int i = 0; i < len; i++) {      

  char codePoint = source.charAt(i);      

  if (!isEmojiCharacter(codePoint)) { //如果不能匹配,则该字符是Emoji表情         

   return true;        }    

}    return false;}

/** * 判断是否是Emoji * * @param codePoint 比较的单个字符 * @return */

private static boolean isEmojiCharacter(char codePoint) {    

return (codePoint == 0x0) || (codePoint == 0x9) || (codePoint == 0xA) ||    

        (codePoint == 0xD) || ((codePoint >= 0x20) && (codePoint <= 0xD7FF)) ||           

 ((codePoint >= 0xE000) && (codePoint <= 0xFFFD)) || ((codePoint >= 0x10000)         

   && (codePoint <= 0x10FFFF));}