Android_EditText输入字数限制与监听

   etSuggestion.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 = etSuggestion.getText();
                int len = editable.length();
                //显示还可以输入多少字
                tvSize.setText(len + "" + "/500");
                if (len > 500) {
                    ToastUtil.showToast(getApplicationContext(), "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, 500);
                    etSuggestion.setText(newStr);
                    editable = etSuggestion.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) {

            }
        });