Android:可以用wrap_content设置SlidingDrawer的高度吗？

Question

我正在尝试实现一个SlidingDrawer占据全屏宽度的内容,但其高度由其内容动态确定:换句话说,fill_parent宽度和wrap_content高度的标准布局行为.这正是我在布局XML中指定它的方式(见下文),但滑动抽屉始终打开到全屏高度.我的内容高度各不相同,但通常它只有屏幕高度的一半左右,所以我最终会在它下面留下一个很大的空隙.我想要的是内容整齐地放在屏幕的底部.

我已经尝试了所有我能想到的东西来解决它但到目前为止还没有任何工作.如果我将SlidingDrawer's layout_height设置为特定值(例如160dip)它可以工作,但这不是我需要的:它必须是动态的.当然,我已经确保所有子元素的高度也都设置wrap_content了.

关于SlidingDrawer的文档在这方面有点模糊,我无法找到任何能够完成我所做的事情的例子.如果有人能看到我出错的地方,我真的很感谢你的帮助!

<RelativeLayout
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <ViewFlipper
        android:id="@+id/ImageFlipper"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >

        <ImageView
            android:id="@+id/imageView0"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:scaleType="centerCrop" />

        <ImageView
            android:id="@+id/imageView1"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:scaleType="centerCrop" />

        <ImageView
            android:id="@+id/imageView2"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:scaleType="centerCrop" />

    </ViewFlipper>

    <SlidingDrawer
        android:id="@+id/infoDrawer"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:handle="@+id/infoDrawerHandle"
        android:content="@+id/infoDrawerContent"
        android:allowSingleTap="false"
        android:layout_alignParentBottom="true"
        android:orientation="vertical" >

        <!-- Sliding drawer handle -->
        <ImageView
            android:id="@id/infoDrawerHandle"
            android:src="@drawable/info_handle_closed"
            android:layout_width="wrap_content" 
            android:layout_height="wrap_content" />

        <!-- Sliding drawer content: a scroller containing a group of text views
        laid out in a LinearLayout -->
        <ScrollView
            android:id="@id/infoDrawerContent"
            android:background="@drawable/info_background"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:fillViewport="false" >

            <LinearLayout
                android:id="@id/infoDrawerContent"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingRight="5dip" >

                <TextView
                    android:id="@+id/infoTitle"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textColor="#ffffff"
                    android:textSize="16dip"
                    android:textStyle="bold" />

                <TextView
                    android:id="@+id/infoCreator"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textColor="#ffffff"
                    android:textSize="14dip"
                    android:textStyle="italic"
                    android:paddingBottom="10dip" />

                <TextView
                    android:id="@+id/infoDescription"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textColor="#ffffff"
                    android:textSize="14dip"
                    android:paddingBottom="10dip" />

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textColor="#ffcc00"
                    android:textSize="14dip"
                    android:textStyle="bold"
                    android:text="@string/heading_pro_tip" />

                <TextView
                    android:id="@+id/infoProTip"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textColor="#ffcc00"
                    android:textSize="14dip" />

            </LinearLayout>    

        </ScrollView>

    </SlidingDrawer>

</RelativeLayout>

Answer 1

onMeasure()SlidingDrawer类的方法基本上覆盖了布局模式fill_parent,这就是为什么layout_height="wrap_content"不工作的原因.

为了解决这个问题,您可以使用重新实现的onMeasure()方法扩展SlidingDrawer,以保证layout_width和layout_height属性.然后,您可以通过更换使用你的XML布局这个自定义类<SlidingDrawer ...>用<fully.qualified.package.ClassName ...>.

请注意,由于抽屉将不再填充父布局,因此您必须将其包含在LinearLayout中,并将gravity属性设置为抽屉所在的边缘.

下面是我为此目的创建的一个类和一个示例布局.

WrappingSlidingDrawer类:

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.SlidingDrawer;


public class WrappingSlidingDrawer extends SlidingDrawer {

    public WrappingSlidingDrawer(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        int orientation = attrs.getAttributeIntValue("android", "orientation", ORIENTATION_VERTICAL);
        mTopOffset = attrs.getAttributeIntValue("android", "topOffset", 0);
        mVertical = (orientation == SlidingDrawer.ORIENTATION_VERTICAL);
    }

    public WrappingSlidingDrawer(Context context, AttributeSet attrs) {
        super(context, attrs);

        int orientation = attrs.getAttributeIntValue("android", "orientation", ORIENTATION_VERTICAL);
        mTopOffset = attrs.getAttributeIntValue("android", "topOffset", 0);
        mVertical = (orientation == SlidingDrawer.ORIENTATION_VERTICAL);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
        int widthSpecSize =  MeasureSpec.getSize(widthMeasureSpec);

        int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
        int heightSpecSize =  MeasureSpec.getSize(heightMeasureSpec);

        if (widthSpecMode == MeasureSpec.UNSPECIFIED || heightSpecMode == MeasureSpec.UNSPECIFIED) {
            throw new RuntimeException("SlidingDrawer cannot have UNSPECIFIED dimensions");
        }

        final View handle = getHandle();
        final View content = getContent();
        measureChild(handle, widthMeasureSpec, heightMeasureSpec);

        if (mVertical) {
            int height = heightSpecSize - handle.getMeasuredHeight() - mTopOffset;
            content.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(height, heightSpecMode));
            heightSpecSize = handle.getMeasuredHeight() + mTopOffset + content.getMeasuredHeight();
            widthSpecSize = content.getMeasuredWidth();
            if (handle.getMeasuredWidth() > widthSpecSize) widthSpecSize = handle.getMeasuredWidth();
        }
        else {
            int width = widthSpecSize - handle.getMeasuredWidth() - mTopOffset;
            getContent().measure(MeasureSpec.makeMeasureSpec(width, widthSpecMode), heightMeasureSpec);
            widthSpecSize = handle.getMeasuredWidth() + mTopOffset + content.getMeasuredWidth();
            heightSpecSize = content.getMeasuredHeight();
            if (handle.getMeasuredHeight() > heightSpecSize) heightSpecSize = handle.getMeasuredHeight();
        }

        setMeasuredDimension(widthSpecSize, heightSpecSize);
    }

    private boolean mVertical;
    private int mTopOffset;
}

示例布局(假设WrappingSlidingDrawer在包com.package中):

<FrameLayout android:layout_width="fill_parent"
             android:layout_height="fill_parent">
    ... stuff you want to cover at full-size ...
    <LinearLayout android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:gravity="bottom"
              android:orientation="vertical">
        <com.package.WrappingSlidingDrawer android:layout_width="fill_parent"
                           android:layout_height="wrap_content"
                           android:content="@+id/content"
                           android:handle="@+id/handle">
            ... handle and content views ...
        </com.package.WrappingSlidingDrawer>
    </LinearLayout>
</FrameLayout>

Answer 2

只需在xml中的滑动抽屉中设置为pmargin即可

android:layout_marginTop="50dip"

Answer 3

seydhe的答案有一个小问题.

getAttributeIntValue的第一个参数需要是完整的命名空间,而不仅仅是"android".所以代码片段应该是:

final String xmlns="http://schemas.android.com/apk/res/android";
int orientation = attrs.getAttributeIntValue(xmlns, "orientation", SlidingDrawer.ORIENTATION_VERTICAL);
 mTopOffset = attrs.getAttributeIntValue(xmlns, "topOffset", 0);

我一直无法使用水平滑动抽屉,直到我意识到它没有找到方向属性,因此将其视为垂直.