here is code activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="@string/usernm_text"
android:id="@+id/username"
android:contentDescription="@string/usernm_text"
android:focusable="true"
android:nextFocusDown="@+id/usr_nm"
/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:ems="10"
android:id="@+id/usr_nm"
android:contentDescription="@string/usernm_text"
android:focusable="true"
android:text="admin"
android:nextFocusDown="@+id/password"
android:nextFocusUp="@id/usr_nm"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="@string/pass_text"
android:id="@+id/password"
android:focusable="true"
android:nextFocusDown="@+id/pass_edit"
android:contentDescription="@string/pass_text"
android:nextFocusUp="@id/usr_nm"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPassword"
android:ems="10"
android:id="@+id/pass_edit"
android:contentDescription="@string/pass_text"
android:text="admin"
android:focusable="true"
android:nextFocusDown="@+id/login"
android:nextFocusUp="@id/password"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/login_btn"
android:onClick="log"
android:id="@+id/login"
android:contentDescription="@string/login_btn"
android:focusable="true"
android:nextFocusUp="@id/pass_edit"
android:accessibilityLiveRegion="polite" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:id="@+id/log_succ"
android:focusable="true"
android:accessibilityLiveRegion="polite" />
</LinearLayout>
触摸时通过对讲登录成功的textview提示。 我希望当我点击登录按钮然后textview“登录成功”应立即通过对话提示。 我将AccessibilityliveRegion设置为“polite”。 我该怎么办?