在滚动型机器人的ListView行没有完全显示出来 - 截取 [英] Android ListView rows in ScrollView not fully displayed - clipped

问题描述

我嵌入一个ListView内的滚动型时遇到了问题，或者至少这就是我想这个问题的来源。 ListView控件元素是一个非常简单的：

I encountered a problem when embedding a ListView inside a ScrollView, or at least that's where I guess the problem comes from. The ListView element is a fairly simple one:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/item_root"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/general_background_list_middle" 
    android:paddingTop="4dp"
    android:paddingBottom="4dp"
    android:paddingRight="0dp"
    android:paddingLeft="0dp">

    <ImageView
        android:id="@+id/chat_friends_avatar"       
        android:layout_width="45dp"
        android:layout_height="45dp"
        android:layout_marginLeft="7dp"
        android:layout_marginRight="8dp"
        android:paddingRight="0dp" 
        android:paddingLeft="0dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:src="@drawable/friends_icon_avatar_default"/>

    <TextView
        android:id="@+id/chat_message_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@id/chat_friends_avatar"
        android:layout_alignParentTop="true"
        android:layout_marginRight="35dp"
        android:maxLines="10"
        android:textSize="12dp"/>

    <TextView
        android:id="@+id/chat_friend_name"
        android:layout_width="140dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="3dp"
        style="@style/SubText"
        android:layout_toRightOf="@id/chat_friends_avatar"      
        android:layout_below="@id/chat_message_text" />

    <TextView
        android:id="@+id/chat_message_time"
        android:layout_width="80dp"
        android:layout_height="wrap_content"
        android:layout_marginRight="8dp"
        android:layout_marginTop="3dp"
        style="@style/SubText"
        android:layout_alignParentRight="true"
        android:layout_below="@id/chat_message_text" />

</RelativeLayout>   

然而，当我嵌入在一个滚动型，这样的元素在一些其他元素之间的列表，这些行没有完全显示出来，它们被裁剪（见下图），如果文本换行。 ListView控件实例化的滚动型如下：

However, when I embed a list of such elements in a ScrollView, in between some other elements, the rows are not fully displayed, they are clipped (see image below) if the text is wrapped. The ListView is instantiated as follows in the ScrollView:

<ListView
android:id="@+id/info_chat_listview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:cacheColorHint="@color/frame_background_color"
android:clickable="false"
android:divider="@null"
android:footerDividersEnabled="false"
android:focusable="false" >
</ListView> 

如果在ListView的高度设定被示为WRAP_CONTENT的第一个元素。这就是为什么我使用的方法来计算列表行的高度：

If the height of the ListView is set to "wrap_content" only the first element is shown. That's why I'm using a method to calculate the height of the rows of the list:

private int getCommentsListHeight() {
        if (mChatAdapter != null && mChatAdapter.getCount() != 0) {
            if (mChatList != null) {// && mCommentsListItemHeight == 0) {
                mCommentsListItemHeight = 0;
                for (int i = 0; i < mChatAdapter.getCount(); i++) {
                    // Get view item height
                    View viewItem = mChatAdapter
                            .getView(i, new View(OnAirActivity.this), mChatList);
                    viewItem.measure(0, 0);
                    Logger.d(LOGTAG, "View " + i + " measured height = " + viewItem.getMeasuredHeight());
                    mCommentsListItemHeight += viewItem.getMeasuredHeight();
                }
            }
            //return mChatAdapter.getCount() * mCommentsListItemHeight;
            return mCommentsListItemHeight;
        } else {
            return 0;
        }
    }

不幸的是，在当的TextView内的文本被包裹，即使在多个行的情况下，由getMeasuredHeight（）方法返回的行元件的高度是不变的。另外，getLineCount（）呼吁该行的元素里面的TextView返回1，即使文本换行。

Unfortunately, in case when the text inside the TextView is wrapped, even over several lines, the height of the row element returned by the getMeasuredHeight() method is constant. Also the getLineCount() called on the TextView inside the row element returns 1 even if the text is wrapped.

在另一方面，如果ListView控件被嵌入的LinearLayout，一切工作正常，完整的列表将显示没有剪辑。

On the other hand, if this ListView is embedded in a LinearLayout, everything works fine and the full list is displayed with no clipping.

你有任何建议，什么可能在这里是错的？我真的不喜欢手动测量列表元素的高度的想法，它显然不工作，但为什么不能很好的android舒展的ListView的滚动型内，以适应这一切呢？

Do you have any suggestions as to what might be wrong here? I really don't like the idea of manually measuring the height of the list elements and it apparently doesn't work but why can't android nicely stretch the ListView inside the ScrollView to fit it all in there?

削峰列表：

Clipped list:

推荐答案

这是一个坏实践封装的ListView A <$ C $内C>滚动型因为ListView控件本身包含滚动功能。您应该实现不包含这种意见层次的解决方案，我希望它会做的魔力：）

It's a BAD practice to encapsulate ListView within a ScrollView because ListView itself contains scrolling capabilities. You should implement a solution that does not contain such hierarchy of views and I hope it will do the magic :)

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