如何修改SearchView的样式

public SearchView createSearchView(Context context) {
        SearchView searchView = new SearchView(context);
        EditText editText = ((EditText) searchView.findViewById(android.support.v7.appcompat.R.id.search_src_text));
        if (editText != null) {
            editText.setTextColor(Color.WHITE);
            editText.setHint(R.string.pleaseEnterNickname);
            editText.setHintTextColor(Color.WHITE);
        }

        ImageView searchCloseIcon = (ImageView) searchView.findViewById(android.support.v7.appcompat.R.id.search_close_btn);
        if (searchCloseIcon != null) {
            searchCloseIcon.setImageResource(R.mipmap.icon_close);
        }

        ImageView voiceIcon = (ImageView) searchView.findViewById(android.support.v7.appcompat.R.id.search_voice_btn);
        if (voiceIcon != null) {
            voiceIcon.setImageResource(R.mipmap.icon_voice_white);
        }

        return searchView;
    }

以下几种方法都不可以自定义搜索按钮图片

ImageView searchIcon = (ImageView) searchView.findViewById(R.id.search_mag_icon);
if (searchIcon != null) {
    searchIcon.setImageResource(R.mipmap.icon_search);
}

ImageView searchIcon = (ImageView) searchView.findViewById(android.support.v7.appcompat.R.id.search_mag_icon);
if (searchIcon != null) {
    searchIcon.setImageResource(R.mipmap.icon_search);
}

int searchIconId = searchView.getContext().getResources().getIdentifier("android:id/search_button", null, null);
ImageView searchIcon = (ImageView) searchView.findViewById(searchIconId);
if (searchIcon != null) {
    searchIcon.setImageResource(R.mipmap.icon_search);
}

最后通过修改showAsAction属性，将其设置为collapseActionView，成功设置自定义图片标

<item xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/menu_search"
        android:actionViewClass="android.support.v7.widget.SearchView"
        android:icon="@mipmap/icon_search"
        android:showAsAction="ifRoom|collapseActionView"
        android:title="@string/menuSearch"
        app:icon="@mipmap/icon_search"
        app:searchIcon="@mipmap/icon_search"
        app:showAsAction="ifRoom|collapseActionView"
        tools:ignore="AppCompatResource" />