Android EditText输入最大值提示功能

public class LengthFilter implements InputFilter {
     public LengthFilter(int max) {
         mMax = max;
     }  

     @Override
     public CharSequence filter(CharSequence source, int start, int end,
             Spanned dest, int dstart, int dend) {
         int keep = mMax - (dest.length() - (dend - dstart));  

         if (keep <= 0) {
             if (mErrorToast == null) {
                 mErrorToast = Toast.makeText(ShowDetailCommentActivity.this, R.string.comment_input_overflow,
                         Toast.LENGTH_SHORT);
             }
             mErrorToast.show();
             return "";
         } else if (keep >= end - start) {
             return null; // keep original
         } else {
             keep += start;
             if (mErrorToast == null) {
                 mErrorToast = Toast.makeText(ShowDetailCommentActivity.this, R.string.comment_input_overflow,
                         Toast.LENGTH_SHORT);
             }
             mErrorToast.show();
             if (Character.isHighSurrogate(source.charAt(keep - 1))) {
                 --keep;
                 if (keep == start) {
                     return "";
                 }
             }
             return source.subSequence(start, keep);
         }
     }  

     private int mMax;
 }  

mEditText.setFilters(new InputFilter[] { new LengthFilter(mMaxTextNum) });  

代码很少但有效，各位可以尝试一下。

作者：xzy2046，转载需注明。博客主页：http://blog.csdn.net/xzy2046