EditText限制输入emoji表情总结

 

实际的项目开发中很多时候要求密码输入时不能输入emoji表情,看了很多大神的博客,决定总结一下,以备以后使用。(注意:有一个单字符的表情是可以输入的···)

// 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;

// edittext监听
	private TextWatcher TextWatcher = new TextWatcher() {

		@Override
		public void beforeTextChanged(CharSequence s, int start, int before,
				int count) {
			try {
				if (!resetText) {
					cursorPos = userpwd.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();
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

		@Override
		public void onTextChanged(CharSequence s, int start, int before,
				int count) {
			try {
				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 (CommonUtils.containsEmoji(input.toString())) {
							resetText = true;
							showMessage("不允许输入表情");
							// 是表情符号就将文本还原为输入表情符号之前的内容
							userpwd.setText(inputAfterText);
							CharSequence text = userpwd.getText();
							if (text instanceof Spannable) {
								Spannable spanText = (Spannable) text;
								Selection.setSelection(spanText, text.length());
							}
						}
					}
				} else {
					resetText = false;
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

		@Override
		public void afterTextChanged(Editable editable) {
			try {
				Editable e = userpwd.getText();
				int position = e.length();
				Selection.setSelection(e, position);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	};

/**
	 * 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
	 */
	public 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));
	}

其中,userpwd为需要限制的EditText,然后在初始化组件的时候调用addTextChangedListener(),比如:userpwd.addTextChangedListener(TextWatcher) 即可。

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