Android 滚动视图'；s子（线性布局）和#x27；s的背景颜色在滚动时更改

我在使用scrollview时遇到了一个我无法解决的奇怪问题

我已经附上了图形视图的屏幕截图，因为我已经为布局背景设置了一种颜色，但在滚动视图时它会发生变化

这是我的密码

一次创建活动

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_discussionlist);


        ll_comments = (LinearLayout) findViewById(R.id.ll_comments);

        for (int i = 0; i < 10; i++) {
            View view = LayoutInflater.from(DiscussionListActivity.this)
                    .inflate(R.layout.comments, null);

            ll_comments.addView(view, ll_comments.getChildCount());
            Log.print(" ll_comments.getChildCount() ="
                    + ll_comments.getChildCount());

        }
    }

@覆盖
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_discussionlist）；
ll_注释=（线性布局）findViewById（R.id.ll_注释）；
对于（int i=0；i<10；i++）{
View=LayoutInflater.from（DiscussionListActivity.this）
.充气（R.layout.comments，空）；
ll_comments.addView（视图，ll_comments.getChildCount（））；
Log.print（“ll_comments.getChildCount（）=”
+ll_comments.getChildCount（））；
}
}

下面是activity_discussionlist.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <RelativeLayout
        android:id="@+id/ll_discussion_content"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <TextView
            android:id="@+id/txt_submenu_content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="-5dp"
            android:background="@drawable/submenu_bg"
            android:gravity="center"
            android:paddingBottom="10dp"
            android:paddingLeft="15dp"
            android:paddingRight="15dp"
            android:paddingTop="10dp"
            android:text="SubMenu"
            android:textColor="#FFFFFF" />

        <ImageView
            android:id="@+id/img_reply"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:layout_marginRight="10dp"
            android:src="@drawable/ic_reply"
            android:visibility="visible" />
    </RelativeLayout>

    <ScrollView
        android:id="@+id/sv_discussion"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:fillViewport="true"
        android:scrollbars="none" >

        <LinearLayout
            android:id="@+id/ll_scroll_main"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

            <RelativeLayout
                android:id="@+id/rl_discussion"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:background="@drawable/discussion_bg"
                android:padding="5dp" >

                <HorizontalScrollView
                    android:id="@+id/hl_title"
                    android:layout_width="fill_parent"
                    android:layout_height="wrap_content"
                    android:layout_alignParentTop="true"
                    android:layout_marginTop="5dp"
                    android:scrollbars="none" >

                    <TextView
                        android:id="@+id/txt_title"
                        style="@style/TextTitleBold"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:singleLine="true"
                        android:text="Homework Questions" />
                </HorizontalScrollView>

                <TextView
                    android:id="@+id/txt_uploadedby_date"
                    style="@style/TextDate"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_below="@+id/hl_title"
                    android:layout_marginTop="5dp"
                    android:ellipsize="end"
                    android:singleLine="true"
                    android:text="by Ralph on Oct 01,2013 6:15 AM"
                    android:textColor="#BBBBBB" />

                <TextView
                    android:id="@+id/txt_posts"
                    style="@style/TextDate"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_below="@+id/txt_uploadedby_date"
                    android:layout_marginTop="5dp"
                    android:ellipsize="end"
                    android:singleLine="true"
                    android:text="12 Comments" />

                <TextView
                    android:id="@+id/txt_descr"
                    style="@style/TextDescription"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_below="@+id/txt_posts"
                    android:layout_marginTop="5dp"
                    android:ellipsize="end"
                    android:singleLine="false"
                    android:text=" 0 down vote favorite I am setting up images for different devices as per official google docs.As per google docs we should always use dp(density independent pixels) because pixels may varies for different devices. So i have managed images as per dp(density independent pixels). I have put images in drawable xhdpi,hdpi,mdpi and ldpi. it works well for most of devices but for different devices ppi pixels may varies from device to device so dp(density independent pixels) is not fixed so my all calculations according to dp(density independent pixels) goes wrong and cannot be set properly." />
            </RelativeLayout>

            <View
                android:id="@+id/view_separator"
                android:layout_width="fill_parent"
                android:layout_height="10dp"
                android:layout_marginTop="10dp"
                android:background="#BBBBBB" />

            <LinearLayout
                android:id="@+id/ll_comments"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="10dp"
                android:orientation="vertical"
                android:padding="10dp" >
            </LinearLayout>
        </LinearLayout>
    </ScrollView>

</LinearLayout>

下面是comments.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="20dp" >

    <FrameLayout
        android:id="@+id/comment_identity"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <LinearLayout
            android:id="@+id/comment_options"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="35dp"
            android:background="#ececec"
            android:gravity="bottom"
            android:orientation="horizontal"
            android:weightSum="2" >

            <LinearLayout
                android:id="@+id/linear_editoption"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:gravity="right|center_vertical"
                android:padding="10dp" >

                <ImageView
                    android:id="@+id/img_edit"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:src="@drawable/img_edit" />

                <TextView
                    android:id="@+id/text_editoption"
                    style="@style/TextDescriptionBold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="5dp"
                    android:text="Edit" />
            </LinearLayout>

            <LinearLayout
                android:id="@+id/linear_deleteoption"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:gravity="center_horizontal|center_vertical"
                android:padding="10dp" >

                <ImageView
                    android:id="@+id/img_delete"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:src="@drawable/img_delete" />

                <TextView
                    android:id="@+id/text_deleteoption"
                    style="@style/TextDescriptionBold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="5dp"
                    android:text="Delete" />
            </LinearLayout>
        </LinearLayout>

        <RelativeLayout
            android:id="@+id/rel_commentphoto"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="10dp"
            android:padding="10dp" >

            <ImageView
                android:id="@+id/img_commentpic"
                android:layout_width="50dp"
                android:layout_height="60dp"
                android:background="@drawable/img_bg"
                android:src="@drawable/profile" />
        </RelativeLayout>

        <RelativeLayout
            android:id="@+id/rel_commentidentity"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >

            <TextView
                android:id="@+id/txt_name"
                style="@style/TextDescriptionBold"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginLeft="70dp"
                android:layout_marginTop="10dp"
                android:singleLine="true"
                android:text="Ralph Johnson" />


            <TextView
                android:id="@+id/txt_date"
                style="@style/TextDate"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginLeft="10dp"
                android:layout_marginTop="10dp"
                android:layout_toRightOf="@+id/txt_name"
                android:singleLine="true"
                android:text="02 Oct,2013 6:00 AM"
                android:textColor="#BBBBBB" />
        </RelativeLayout>
    </FrameLayout>

    <TextView
        android:id="@+id/txt_comment"
        style="@style/TextDate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/comment_identity"
        android:layout_marginTop="5dp"
        android:singleLine="false"
        android:text="This is test comment.Post your comments here." />

    <View
        android:layout_width="fill_parent"
        android:layout_height="1dp"
        android:layout_below="@+id/txt_comment"
        android:layout_marginTop="20dp"
        android:background="#DDDDDD" />

</RelativeLayout>

大家可以看到，我在comments.xml文件中将背景色仅设置为线性布局（线性布局的id为“comment_options”）

我在下图中标出了红色圆圈。请看区别

---

问题不在于布局定义或颜色分配。由于您没有在

activity\u discussionlist.xml

中设置基本容器的后台属性，因此为应用程序主题定义的

windowBackground

属性将发挥作用

您当前看到的是一个渐变，定义为：

screen_background_selector_light.xml：

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient
    android:startColor="#ffe8e8e8"
    android:endColor="#ffffffff"
    android:angle="270" />
</shape>

在行动中：

在上图中，所有四个线性布局（每个都位于文本视图上方）都是相同的，其背景设置为“#ECECEC”。视觉上的区别来自活动的背景，这是一个渐变

因此，如果将父容器的background属性（根级别LinearLayout in

activity\u discussionlist.xml

）设置为“#ECECEC”或您喜欢的任何其他颜色，这个问题就会得到解决。梯度是你不想要的

(taken from platforms/android-17/data/res/values/themes.xml)
<style name="Theme.Light">
    <item name="windowBackground">@android:drawable/screen_background_selector_light</item>
    ....

lightest background      ==>>     #ECECEC on mostly #E8E8E8
lighter background       ==>>     #ECECEC on (#E8E8E8 + a bit of #FFFFFF)
less lighter background  ==>>     #ECECEC on (#FFFFFF + a bit of #E8E8E8)
dark background          ==>>     #ECECEC on mostly #FFFFFF