在我当前的 Android 应用程序中，我有一个显示 android.support.v4.app.DialogFragment 的屏幕。
此 DialogFragment View 包含以下 UI 组件
HEADING
== Sub Heading
== NestedScrollView
==== RecyclerView
==== RadioGroup
==== Spinner
==== EditText
==== Action Buttons
DialogFragment 使用样式配置为全屏，如下所示:-
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setStyle(DialogFragment.STYLE_NO_TITLE, R.style.AppDialogTheme);
}
我的对话风格是
<!-- Define your custom dialog theme here extending from base -->
<style name="AppDialogTheme" parent="Theme.AppCompat.Light.Dialog">
<!-- Define color properties as desired -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">#000</item>
<item name="android:textColorHighlight">@color/background_url</item>
<item name="colorAccent">@color/dark_grey</item>
<item name="colorControlNormal">@color/colorPrimaryDark</item>
<!-- Define window properties as desired -->
<item name="android:windowNoTitle">true</item>
<item name="android:windowFullscreen">true</item>
<item name="android:windowBackground">@android:color/white</item>
<item name="android:windowIsFloating">true</item>
<item name="android:windowCloseOnTouchOutside">false</item>
</style>
我使用 NestedScrollView 的原因是 View 可以在纵向和横向模式下工作。
我想限制 RecyclerView 的高度
我得到的最接近的是使用下面的布局。
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/headline_literal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:gravity="center"
android:padding="10dp"
android:text="Heading"
android:textSize="20sp"
android:textStyle="bold" />
<View
android:id="@+id/divider"
android:layout_width="fill_parent"
android:layout_height="2dp"
android:layout_marginTop="5dp"
android:background="#c0c0c0" />
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:weightSum="5"
android:orientation="vertical">
<TextView
android:id="@+id/sub_headline_literal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="10dp"
android:text="Some long texts having a long size so that it takes multiple lines in the view to replicate the real-life app use case. This is important to have 3-4 lines this textview so that we can see if the views are being populated correctly. Hope this sentence is long enough to replicate the real-life scenario of this TextView content. Thank you."
android:textSize="16sp"
android:textStyle="normal" />
<android.support.v7.widget.RecyclerView
android:id="@+id/dummy_rv"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_margin="10dp"
android:layout_marginStart="9dp"
android:layout_marginEnd="9dp"
android:layout_weight="1"
android:background="@drawable/rv_border"
android:fadingEdge="horizontal"
android:fadingEdgeLength="10dp"
android:padding="10dp"
android:requiresFadingEdge="vertical" />
<RadioGroup
android:id="@+id/myRadioGroup"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="10dp"
android:checkedButton="@+id/sound">
<RadioButton
android:id="@+id/sound"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sound" />
<RadioButton
android:id="@+id/vibration"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Vibration" />
<RadioButton
android:id="@+id/silent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Silent" />
</RadioGroup>
<EditText
android:id="@+id/notes"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Notes" />
<LinearLayout
android:id="@+id/buttons"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="10dp">
<TextView
android:id="@+id/cancel_button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:text="Cancel" />
<TextView
android:id="@+id/submit_button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:text="Submit" />
</LinearLayout>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
</LinearLayout>
通过在 NestedScrollView 的内部 LinearLayout 上使用 weightSum，我可以限制 Recyclerview 的高度。然而，NestedScrollView 高度太大，一半以上的高度是空白的。
如何限制 RecyclerView 的高度并将 NestedScrollView 设置为 wrap_content？
我试过 NestedScrollView 的高度 wrap_content 但这没有效果。
如何实现所需的用户界面？提前致谢!
最佳答案
我建议不要使用 NestedRecyclerView，而是将页眉和页脚添加到您的 RecyclerView 中，这样可以很好地放置整体内容看过你的布局。我想为您提供一个链接 my answer here您可以在其中找到如何在 RecyclerView 中添加页脚和页眉。
因此，我想建议使用 headline_literal 和 divider 创建一个 View ，并将其用作标题，而 RadioGroup， EditText 和 Button 将位于页脚中。如果您遇到任何问题，请告诉我。
我已经尝试自己实现您想要的行为，请告诉我以下实现是否适合您。我在 Github 中添加了这个以及。
让我们首先声明一个适配器，用于向 RecyclerView 添加页眉和页脚。
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import java.util.ArrayList;
public class RecyclerViewWithHeaderFooterAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static final int FOOTER_VIEW = 1;
private static final int HEADER_VIEW = 2;
private ArrayList<String> data; // Take any list that matches your requirement.
private Context context;
// Define a constructor
public RecyclerViewWithHeaderFooterAdapter(Context context, ArrayList<String> data) {
this.context = context;
this.data = data;
}
// Define a ViewHolder for Header view
public class HeaderViewHolder extends ViewHolder {
public HeaderViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Do whatever you want on clicking the item
}
});
}
}
// Define a ViewHolder for Footer view
public class FooterViewHolder extends ViewHolder {
public FooterViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Do whatever you want on clicking the item
}
});
}
}
// Now define the ViewHolder for Normal list item
public class NormalViewHolder extends ViewHolder {
public NormalViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Do whatever you want on clicking the normal items
}
});
}
}
// And now in onCreateViewHolder, you have to pass the correct view
// while populating the list item.
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v;
if (viewType == FOOTER_VIEW) {
v = LayoutInflater.from(context).inflate(R.layout.list_item_footer, parent, false);
FooterViewHolder vh = new FooterViewHolder(v);
return vh;
} else if (viewType == HEADER_VIEW) {
v = LayoutInflater.from(context).inflate(R.layout.list_item_header, parent, false);
HeaderViewHolder vh = new HeaderViewHolder(v);
return vh;
}
// Otherwise populate normal views
v = LayoutInflater.from(context).inflate(R.layout.list_item_normal, parent, false);
NormalViewHolder vh = new NormalViewHolder(v);
return vh;
}
// Now bind the ViewHolder in onBindViewHolder
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
try {
if (holder instanceof NormalViewHolder) {
NormalViewHolder vh = (NormalViewHolder) holder;
vh.bindView(position);
} else if (holder instanceof FooterViewHolder) {
FooterViewHolder vh = (FooterViewHolder) holder;
} else if (holder instanceof HeaderViewHolder) {
HeaderViewHolder vh = (HeaderViewHolder) holder;
}
} catch (Exception e) {
e.printStackTrace();
}
}
// Now the critical part. You have return the exact item count of your list
// I've only one footer. So I returned data.size() + 1
// If you've multiple headers and footers, you've to return total count
// like, headers.size() + data.size() + footers.size()
@Override
public int getItemCount() {
if (data == null) {
return 0;
}
if (data.size() == 0) {
// Return 1 here to show nothing
return 1;
}
// Add extra view to show the header view
// Add another extra view to show the footer view
// So there are two extra views need to be populated
return data.size() + 2;
}
// Now define getItemViewType of your own.
@Override
public int getItemViewType(int position) {
if (position == 0) {
// This is where we'll add the header.
return HEADER_VIEW;
} else if (position == data.size() + 1) {
// This is where we'll add a footer.
return FOOTER_VIEW;
}
return super.getItemViewType(position);
}
// So you're done with adding a footer and its action on onClick.
// Now set the default ViewHolder for NormalViewHolder
public class ViewHolder extends RecyclerView.ViewHolder {
// Define elements of a row here
public ViewHolder(View itemView) {
super(itemView);
// Find view by ID and initialize here
}
public void bindView(int position) {
// bindView() method to implement actions
}
}
}
现在让我们一一定义布局。这是 list_item_normal.xml。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/normal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp"
android:text="This is a text to be displayed in each item in the RecyclerView"
android:textSize="16sp"
android:textStyle="normal" />
</LinearLayout>
list_item_footer.xml 应该如下所示。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:orientation="vertical">
<RadioGroup
android:id="@+id/myRadioGroup"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="10dp"
android:checkedButton="@+id/sound">
<RadioButton
android:id="@+id/sound"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sound" />
<RadioButton
android:id="@+id/vibration"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Vibration" />
<RadioButton
android:id="@+id/silent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Silent" />
</RadioGroup>
<EditText
android:id="@+id/notes"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Notes" />
<LinearLayout
android:id="@+id/buttons"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="10dp">
<TextView
android:id="@+id/cancel_button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:text="Cancel" />
<TextView
android:id="@+id/submit_button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:text="Submit" />
</LinearLayout>
</LinearLayout>
最后，list_item_header.xml 应具有以下内容。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/sub_headline_literal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="10dp"
android:text="Some long texts having a long size so that it takes multiple lines in the view to replicate the real-life app use case. This is important to have 3-4 lines this textview so that we can see if the views are being populated correctly. Hope this sentence is long enough to replicate the real-life scenario of this TextView content. Thank you."
android:textSize="16sp"
android:textStyle="normal" />
</LinearLayout>
现在您已将原始布局的组件分成几部分。因此，主要布局应如下所示。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/headline_literal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:gravity="center"
android:padding="10dp"
android:text="Heading"
android:textSize="20sp"
android:textStyle="bold" />
<View
android:id="@+id/divider"
android:layout_width="fill_parent"
android:layout_height="2dp"
android:layout_marginTop="5dp"
android:background="#c0c0c0" />
<android.support.v7.widget.RecyclerView
android:id="@+id/dummy_rv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:padding="10dp" />
</LinearLayout>
因此，我分享了一个示例 Activity 来运行这段代码，它将显示整体实现。
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private ArrayList<String> data = new ArrayList<String>();
private RecyclerViewWithHeaderFooterAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initializeData();
initializeRecyclerView();
}
private void initializeRecyclerView() {
mRecyclerView = findViewById(R.id.dummy_rv);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
adapter = new RecyclerViewWithHeaderFooterAdapter(this, data);
mRecyclerView.setAdapter(adapter);
}
private void initializeData() {
for (int i = 0; i < 10; i++) data.add("Position :" + i);
}
}
希望对您有所帮助!
关于java - 如何限制 NestedScrollView 内 RecyclerView 的高度，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/54823299/