在开发中可能多处会用到过滤Emoji表情符，一般情况下，我们会通过EditText的addTextChangedListener()监听来过滤Emoji表情，但在实际开发中会遇到多个EditText，为了方便使用，我们可以自定义EditText来实现，代码如下：

package com.piesat.dragonfly.ui.view;

import android.content.Context;

import android.text.Editable;

import android.text.Selection;

import android.text.Spannable;

import android.text.TextWatcher;

import android.util.AttributeSet;

import android.widget.EditText;

import android.widget.Toast;

/**

* @Description EditText限制输入表情符号

* @Authour zhoujp

* @Time 2016年11月18日 下午2:09:58

*

*/

public class ContainsEmojiEditText extends EditText {

// 输入表情前的光标位置

private int cursorPos;

// 输入表情前EditText中的文本

private String inputAfterText;

// 是否重置了EditText的内容

private boolean resetText;

private Context mContext;

public ContainsEmojiEditText(Context context) {

super(context);

this.mContext = context;

initEditText();

}

public ContainsEmojiEditText(Context context, AttributeSet attrs) {

super(context, attrs);

this.mContext = context;

initEditText();

}

public ContainsEmojiEditText(Context context, AttributeSet attrs, int defStyleAttr) {

super(context, attrs, defStyleAttr);

this.mContext = context;

initEditText();

}

// 初始化edittext 控件

private void initEditText() {

addTextChangedListener(new TextWatcher() {

@Override

public void beforeTextChanged(CharSequence s, int start, int before, int count) {

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();

}

}

@Override

public void onTextChanged(CharSequence s, int start, int before, int count) {

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);

if (containsEmoji(input.toString())) {

resetText = true;

Toast.makeText(mContext, "不支持输入表情符号！", 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 editable) {

}

});

}

/**

* 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));

}

}