android 輸入框EditText禁止輸入Emoji表情符
阿新 • • 發佈:2019-02-14
通過新增EditText的addTextChangedListener()監聽來過濾Emoji表情:
- onTextChanged()
- beforeTextChanged()
- 使用方法
- 在開發中可能多處會用到過濾Emoji表情符,為了方便使用自定義EditText來實現:
import android.widget.EditText; import android.widget.Toast; import android.content.Context; import android.text.Editable; import android.text.Selection; import android.text.Spannable; import android.text.TextWatcher; import android.util.AttributeSet; public class ContainsEmojiEditText extends EditText { //輸入表情前的游標位置 private int cursorPos; //輸入表情前EditText中的文字 private String inputAfterText; //是否重置了EditText的內容 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 控制元件 private void initEditText() { addTextChangedListener(new TextWatcher() { @Override public void beforeTextChanged(CharSequence s, int start, int before, int count) { if (!resetText) { cursorPos = getSelectionEnd(); // 這裡用s.toString()而不直接用s是因為如果用s, // 那麼,inputAfterText和s在記憶體中指向的是同一個地址,s改變了, // inputAfterText也就改變了,那麼表情過濾就失敗了 inputAfterText= s.toString(); } } @Override public void onTextChanged(CharSequence s, int start, int before, int count) { if (!resetText) { if (count >= 2) {//表情符號的字元長度最小為2 CharSequence input = s.subSequence(cursorPos, cursorPos + count); if (containsEmoji(input.toString())) { resetText = true; Toast.makeText(mContext, "不支援輸入Emoji表情符號", Toast.LENGTH_SHORT).show(); //是表情符號就將文字還原為輸入表情符號之前的內容 setText(inputAfterText); CharSequence text = getText(); if (text instanceof Spannable) { Spannable spanText = (Spannable) text; Selection.setSelection(spanText, text.length()-1); } } } } else { resetText = false; } } @Override public void afterTextChanged(Editable editable) { } }); } /** * 檢測是否有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,則該字元是Emoji表情 return true; } } return false; } /** * 判斷是否是Emoji * * @param codePoint 比較的單個字元 * @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)); } }
xml檔案使用方法
<com.liujy.ui.wiget.ContainsEmojiEditText
android:layout_width="match_parent"
android:layout_height="wrap_content" />
不過我這邊用的是魅族的輸入法,發現它預設的輸入法在輸入時會發現越界錯誤,如果大家有什麼好的修改建議,就提出來,同時歡迎大家探討。