这是我在stackoverflow中的第一个问题。如果您对任何内容都不了解，我对此感到抱歉：我应该使用片段代替Framelayout吗？
这是我的底部导航
```
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@id/bottomnavid"
>
</FrameLayout>
<android.support.design.widget.BottomNavigationView
android:id="@+id/bottomnavid"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:menu="@menu/bottom_nav"
/>
```
这是我的recyclerview xml的xml：
```
<android.support.v7.widget.RecyclerView
android:id="@+id/featurerecyclerid"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</FrameLayout>
```
这是我的myadapter类别：
```
@NonNull
@Override
public Myviewholder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(c).inflate(R.layout.cardview,viewGroup,false);
Myviewholder VH = new Myviewholder(v);
return VH;
}
//replacing the contents of a view
@Override
public void onBindViewHolder(@NonNull Myviewholder myviewholder, int i) {
myviewholder.nametext.setText(Citynames.get(i));
}
@Override
public int getItemCount() {
return Citynames.size();
}
}
该项目的构建没有任何错误，但未显示recyclerview，我如何在此部分中实现recyclerview，我认为问题在这里。请帮帮我
public class Feature extends Fragment {
ArrayList<String> Citynames = new ArrayList<> (Arrays.asList("dhaka","rongpur","bagura","sylhet","vhola"));
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.feature,container,false);
final FragmentActivity c = getActivity();
final RecyclerView recyclerView = view.findViewById(R.id.featurerecyclerid);
LinearLayoutManager layoutManager = new LinearLayoutManager(c);
recyclerView.setLayoutManager(layoutManager);
Myadapter myadapter = new Myadapter(Citynames,c);
recyclerView.setAdapter(myadapter);
return inflater.inflate(R.layout.feature,container,false);
}
}
```
答案 0 :(得分：0)
我不确定您真正想做的是什么，我觉得您对布局有误，在尝试使用回收站视图之前，请先练习一些不同类型的布局，这将有助于您了解设计对象在xmal属性中的工作方式，这样尝试布局
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@id/bottomnavid"
>
<android.support.v7.widget.RecyclerView
android:id="@+id/featurerecyclerid"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<android.support.design.widget.BottomNavigationView
android:id="@+id/bottomnavid"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:menu="@menu/bottom_nav"
/>
</FrameLayout>
您是否创建了用于初始化R.layout.cardview的任何内部类？另一件事是，您必须在Fragment的RecyclerView方法中使用Adapter初始化onViewCreated()并将其设置为 @Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
final FragmentActivity c = getActivity();
final RecyclerView recyclerView = view.findViewById(R.id.featurerecyclerid);
LinearLayoutManager layoutManager = new LinearLayoutManager(c);
recyclerView.setLayoutManager(layoutManager);
Myadapter myadapter = new Myadapter(Citynames,c);
recyclerView.setAdapter(myadapter);
}
。
package com.example.finalapp;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import com.wajahatkarim3.easyflipview.EasyFlipView;
import java.util.Collections;
import java.util.ArrayList;
public class cardFlipPage extends AppCompatActivity {
final ImageView[] cards = new ImageView[16]; //Array of Card Objects
final int[] cardFaces = new int[8]; //Array of Card Drawables
ArrayList<Integer> cardValues = new ArrayList(); //Array List of Values corresponding to Drawables (to randomize)
final EasyFlipView[] card = new EasyFlipView[16]; //Card objects of EasyFlipView classifier
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_card_flip_page);
//------------------------ Assign Card Objects and Set Up Click Listeners using setListeners() Function-----------------------------
cards[0] = findViewById(R.id.card1Front);
cards[1] = findViewById(R.id.card2Front);
cards[2] = findViewById(R.id.card3Front);
cards[3] = findViewById(R.id.card4Front);
cards[4] = findViewById(R.id.card5Front);
cards[5] = findViewById(R.id.card6Front);
cards[6] = findViewById(R.id.card7Front);
cards[7] = findViewById(R.id.card8Front);
cards[8] = findViewById(R.id.card9Front);
cards[9] = findViewById(R.id.card10Front);
cards[10] = findViewById(R.id.card11Front);
cards[11] = findViewById(R.id.card12Front);
cards[12] = findViewById(R.id.card13Front);
cards[13] = findViewById(R.id.card14Front);
cards[14] = findViewById(R.id.card15Front);
cards[15] = findViewById(R.id.card16Front);
setListeners();
//-------------------------Assign EasyFlipView Objects based on Card Objects----------------------------------------------------------
card[0] = findViewById(R.id.card1);
card[1] = findViewById(R.id.card2);
card[2] = findViewById(R.id.card3);
card[3] = findViewById(R.id.card4);
card[4] = findViewById(R.id.card5);
card[5] = findViewById(R.id.card6);
card[6] = findViewById(R.id.card7);
card[7] = findViewById(R.id.card8);
card[8] = findViewById(R.id.card9);
card[9] = findViewById(R.id.card10);
card[10] = findViewById(R.id.card11);
card[11] = findViewById(R.id.card12);
card[12] = findViewById(R.id.card13);
card[13] = findViewById(R.id.card14);
card[14] = findViewById(R.id.card15);
card[15] = findViewById(R.id.card16);
//-------------------------Assign Card Face Drawables to CardFaces Array for use in for() loop-----------------------------------------
cardFaces[0] = R.drawable.heartcard;
cardFaces[1] = R.drawable.starcard;
cardFaces[2] = R.drawable.xcard;
cardFaces[3] = R.drawable.arrowcard;
cardFaces[4] = R.drawable.diamondcard;
cardFaces[5] = R.drawable.lightningcard;
cardFaces[6] = R.drawable.mooncard;
cardFaces[7] = R.drawable.trianglecard;
//--------------------------Assign integer values to CardFaces in RandPlace() function--------------------------------------------------
cardValues.add(0);
cardValues.add(0);
cardValues.add(1);
cardValues.add(1);
cardValues.add(2);
cardValues.add(2);
cardValues.add(3);
cardValues.add(3);
cardValues.add(4);
cardValues.add(4);
cardValues.add(5);
cardValues.add(5);
cardValues.add(6);
cardValues.add(6);
cardValues.add(7);
cardValues.add(7);
//Create board placement through RNG each time the page is created and closed again----------------------------------------------------
randPlace();
}
public void randPlace() {
for (int x = 0; x <= 15; x++) { //Iterate 16 times through the for loop, accounting for each of the 16 cards[] objects
Collections.shuffle(cardValues); //Shuffle all items in cardValues array to place in pairs
int y = cardValues.get(0); //Get the first element in the cardValues array each iteration of the for() loop
cards[x].setImageResource(cardFaces[y]); //Set the card images to the cardFaces objects of the y value obtained in previous line
cards[x].setTag(y); //Create a tag for each cards[] object for comparison outside the function randPlace()
cardValues.remove(0); //Remove the first element in the cardValues array after each iteration to eliminate more than two copies of each card
cards[x].setPressed(false);
}
}
public void showMatches(int x){
Integer cardTag = (Integer) cards[x].getTag(); //Get tag of specified "x" card in the card[] array for comparison
for(int y = 0; y <= 15; y++){
Integer card2Tag = (Integer) cards[y].getTag(); //Get tag of card "y" each iteration of the for() loop for comparison
if(y==x){ //Add condition to for() loop to skip the specified "x" card so it doesn't compare to itself
continue;
}
else if(cardTag == card2Tag){ //If tag of card "y" is equal to specified card "x", flip it. Updated each iteration.
card[y].flipTheView();
}
}
}
public void setListeners(){
for(int x = 0; x <= 15; x++){ //Set onClickListeners to each cards[] object during each iteration
final int finalX = x;
cards[x].setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
card[finalX].flipTheView();
showMatches(finalX);
}
});
}
}
}