android edittext 输入手机号码格式变化

android edittext 输入内容只能是xxx-xxxx-xxxx格式的手机号码
EditText phoneEt = (EditText) findViewById(R.id.phone_et);
phoneEt.addTextChangedListener(new MyTextWatcher());
private class MyTextWatcher implements TextWatcher {

		@Override
		public void afterTextChanged(Editable s) {
			// TODO Auto-generated method stub
			if (s.length() == 13) {
				requestPhoneAddress();
			}
		}

		@Override
		public void beforeTextChanged(CharSequence s, int start, int count,
				int after) {
			// TODO Auto-generated method stub
		}

		@Override
		public void onTextChanged(CharSequence s, int start, int before,
				int count) {
			String temp = s.toString();
			String addChar = temp.substring(start);
			String str = phoneEt.getText().toString();
			if (temp.length() == 3 || temp.length() == 8) {
				if (StringUtil.isEmpty(addChar)) {
					temp += "-";
					phoneEt.setText(temp);
					phoneEt.setSelection(temp.length());
				}
			}
		}
	}