EditTextView 设置数字密码

 mEdtPassword.setInputType(InputType.TYPE_CLASS_NUMBER | InputType.TYPE_NUMBER_VARIATION_PASSWORD);
 mEdtPassword.setFilters(new InputFilter[]{new InputFilter.LengthFilter(6) {
            }});
mEdtPassword.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
mEdtPassword.setTransformationMethod(PasswordTransformationMethod.getInstance());