在drawable目录下，新建一个 shape_border_top_bottom.xml 文件

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- item 的top left right bottom 相当于margin 设置不需要的边为负值 -->
    <item
        android:top="-1dp"  
        android:left="-1dp"
        android:right="-1dp">
        <shape>
            <!-- 边框颜色 -->
            <stroke
                android:width="0.6dp"
                android:color="@color/c_d0c4ae"/>
             <!-- 背景填充 -->
            <solid android:color="@color/bg_title_bar"/>
        </shape>
    </item>
</layer-list>

怎么用这个文件就不用多逼逼了吧，直接当background用

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="@drawable/shape_border_top_bottom"
    android:gravity="center_vertical"
    android:orientation="horizontal"
    android:paddingLeft="16dp"
    android:paddingRight="16dp">

    <com.sanxin.ttreader.view.SearchEditText
        android:id="@+id/searchEditText"
        android:layout_width="0dp"
        android:layout_height="30dp"
        android:layout_weight="1"
        android:background="@drawable/shape_search_bg"
        android:drawableLeft="@mipmap/search"
        android:drawablePadding="5dp"
        android:gravity="center_vertical"
        android:hint="@string/search_edittext_hint"
        android:textColorHint="@color/c_958669"
        android:imeOptions="actionSearch"
        android:maxLines="1"
        android:padding="5dp"
        android:textCursorDrawable="@drawable/shape_text_cursor_drawable"
        android:textSize="16sp"
        app:drawableDel="@mipmap/main_seach" />

    <TextView
        android:id="@+id/cancel_btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingLeft="10dp"
        android:paddingRight="4dp"
        android:textColor="@color/c_4C3D1B"
        android:text="@string/cancel" />

</LinearLayout>