1. 基本原理：
SearchView是android中一个搜索框组件，它不是一个单独的view，而是一个LinearLayout布局，包括表示Search图标和清除图标等其它图标的imageView、具有下拉建议列表的AutoCompleteTextView等，有时候我们需要对SearchView做一些特定的修改，而SearchView本身却又没有提供相关的接口，这时需要对SearchView进行自顶向下的深度遍历，提取它的每一个子孙view，如果只要对特定类型的view进行修改，只需根据view的类型来提取（view
instanceof XXXView），若要提取特定的某一个view，则需要知道该view的id号，可以从SearchView源代码找到。
2. SearchView的层级结构：search_view.xml
源
代码url：https://github.com/android/platform_frameworks_base/blob/master/core/res/res/layout/search_view.xml#L75
<?xml version="1.0" encoding="utf-8"?>
<!--
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
-->
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/search_bar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
>
<!-- This is actually used for the badge icon *or* the badge label (or neither) -->
<TextView
android:id="@+id/search_badge"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:layout_marginBottom="2dip"
android:drawablePadding="0dip"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="?android:attr/textColorPrimary"
android:visibility="gone"
/>
<ImageView
android:id="@+id/search_button"
style="?android:attr/actionButtonStyle"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center_vertical"
android:src="?android:attr/searchViewSearchIcon"
android:contentDescription="@string/searchview_description_search"
/>
<LinearLayout
android:id="@+id/search_edit_frame"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_gravity="center_vertical"
android:layout_marginTop="4dip"
android:layout_marginBottom="4dip"
android:layout_marginLeft="8dip"
android:layout_marginRight="8dip"
android:orientation="horizontal">
<ImageView
android:id="@+id/search_mag_icon"
android:layout_width="@dimen/dropdownitem_icon_width"
android:layout_height="wrap_content"
android:scaleType="centerInside"
android:layout_marginLeft="@dimen/dropdownitem_text_padding_left"
android:layout_gravity="center_vertical"
android:src="?android:attr/searchViewSearchIcon"
android:visibility="gone"
/>
<!-- Inner layout contains the app icon, button(s) and EditText -->
<LinearLayout
android:id="@+id/search_plate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_gravity="center_vertical"
android:orientation="horizontal"
android:background="?android:attr/searchViewTextField">
<view class="android.widget.SearchView$SearchAutoComplete"
android:id="@+id/search_src_text"
android:layout_height="36dip"
android:layout_width="0dp"
android:layout_weight="1"
android:minWidth="@dimen/search_view_text_min_width"
android:layout_gravity="bottom"
android:paddingLeft="@dimen/dropdownitem_text_padding_left"
android:paddingRight="@dimen/dropdownitem_text_padding_right"
android:singleLine="true"
android:ellipsize="end"
android:background="@null"
android:inputType="text|textAutoComplete|textNoSuggestions"
android:imeOptions="actionSearch"
android:dropDownHeight="wrap_content"
android:dropDownAnchor="@id/search_edit_frame"
android:dropDownVerticalOffset="0dip"
android:dropDownHorizontalOffset="0dip"
android:contentDescription="@string/searchview_description_query"
/>
<ImageView
android:id="@+id/search_close_btn"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:paddingLeft="8dip"
android:paddingRight="8dip"
android:layout_gravity="center_vertical"
android:background="?android:attr/selectableItemBackground"
android:src="?android:attr/searchViewCloseIcon"
android:focusable="true"
android:contentDescription="@string/searchview_description_clear"
/>
</LinearLayout>
<LinearLayout
android:id="@+id/submit_area"
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:background="?android:attr/searchViewTextFieldRight">
<ImageView
android:id="@+id/search_go_btn"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center_vertical"
android:paddingLeft="16dip"
android:paddingRight="16dip"
android:background="?android:attr/selectableItemBackground"
android:src="?android:attr/searchViewGoIcon"
android:visibility="gone"
android:focusable="true"
android:contentDescription="@string/searchview_description_submit"
/>
<ImageView
android:id="@+id/search_voice_btn"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center_vertical"
android:paddingLeft="16dip"
android:paddingRight="16dip"
android:src="?android:attr/searchViewVoiceIcon"
android:background="?android:attr/selectableItemBackground"
android:visibility="gone"
android:focusable="true"
android:contentDescription="@string/searchview_description_voice"
/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
3. 实例框架：
private void traversSearchView(View view, int index) {
if (view instanceof SearchView) {
SearchView searchView = (SearchView)view;
for (int i = 0; i < searchView.getChildCount(); ++i) {
traverseSearchView(searchView.getChildAt(i), i);
}
}
else if (view instanceof LinearLayout) {
if (/*id value from search_view.xml*/ == view.getId()) {
//TODO
}
LinearLayout linearlayout = (LinearLayout)view;
for (int i = 0; i < linearlayout.getChildAt(i), i) {
traverseSearchView(linearlayout.getChildAt(i), i);
}
}
else if (view instanceof EditText) {
if (/*id value from search_view.xml*/ == view.getId()) {
//TODO
}
//TODO
}
else if (view instanceof ImageView) {
if (/*id value from search_view.xml*/ == view.getId()) {
//TODO
}
//TODO
}
//other 'else if' clause
}