对EditText输入字数限制并提示

private int num = 500;//详情描述限制的最大字数

etDetailDescription.addTextChangedListener(new TextWatcher() {@Override public void beforeTextChanged(CharSequence s, int start, int count, int after) {}@Override public void onTextChanged(CharSequence s, int start, int before, int count) {Editable editable = etDetailDescription.getText(); int len = editable.length(); if (len > num) {showToast("超出字数限制"); int selEndIndex = Selection.getSelectionEnd(editable); String str = editable.toString(); //截取新字符串 String newStr = str.substring(0, num); etDetailDescription.setText(newStr); editable = etDetailDescription.getText(); //新字符串的长度 int newLen = editable.length(); //旧光标位置超过字符串长度 if (selEndIndex > newLen) {selEndIndex = editable.length(); }//设置新光标所在的位置 Selection.setSelection(editable, selEndIndex); }}@Override public void afterTextChanged(Editable s) {}});