如何為android recyclerview網格布局設置邊框。

Question

我想要一個看起來像這樣的視圖，一個沒有項目間距的邊框。

目前我的視圖看起來像這樣，我正在使用帶有卡片視圖布局的recyclerview。

下面是我每個項目的代碼

single_item_homepage xml：

<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="95dp"
android:layout_height="95dp"
android:layout_margin="8dp"
>

    <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/imageViewCategory"
        android:layout_width="match_parent"
        android:layout_height="75dp"
        />

    <TextView
        android:text="Shirt"
        android:id="@+id/textViewCategory"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:textSize="15sp"/>


    </LinearLayout>

</android.support.v7.widget.CardView>

主頁活動：

public class HomepageActivity extends AppCompatActivity {


private RecyclerView recyclerView;
private ImageAdapter imageAdapter;

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

    recyclerView = findViewById(R.id.recyclerView);
    imageAdapter = new ImageAdapter(this);

    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new GridLayoutManager(HomepageActivity.this,3));
    recyclerView.setAdapter(imageAdapter);

    }
}

這是我的適配器類：

public class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ImageViewHolder> {


private Context context;

public ImageAdapter(Context context) {
    this.context = context;
}

private int[] resourceId = new int[] {R.drawable.shirt,R.drawable.sleeveless,R.drawable.outerwear,
        R.drawable.sweater,R.drawable.pants,R.drawable.shorts,R.drawable.skirt,R.drawable.dresses,
        R.drawable.shoes,R.drawable.bags,R.drawable.accessories,R.drawable.swimwear
};

private String[] names = new String[]{
        "Shirts","Sleevless","Outerwear","Sweater","Pants","Shorts","Skirts","Dresses","Shoes","Bags","Accessories","Swimwear"
};



@NonNull
@Override
public ImageAdapter.ImageViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View v = LayoutInflater.from(context).inflate(R.layout.single_item_homepage,parent,false);
    return new ImageViewHolder(v);
}

@Override
public void onBindViewHolder(@NonNull ImageAdapter.ImageViewHolder holder, int position) {
    String currName = names[position];
    int currResource = resourceId[position];
    holder.categoryName.setText(currName);
    holder.categoryImage.setImageResource(currResource);

}

@Override
public int getItemCount() {
    return names.length;
}

class ImageViewHolder extends RecyclerView.ViewHolder {

    TextView categoryName;
    ImageView categoryImage;


    public ImageViewHolder(View itemView) {
        super(itemView);

        categoryName = itemView.findViewById(R.id.textViewCategory);
        categoryImage = itemView.findViewById(R.id.imageViewCategory);
        }
    }
}

有沒有辦法改變Recyclerview邊界？ 提前致謝 ：）

Answer 1

HomepageActivity.java

recyclerView = findViewById(R.id.recyclerView);
imageAdapter = new ImageAdapter(this);

recyclerView.setHasFixedSize(true);
recyclerView.addItemDecoration(new DividerItemDecoration(this,
                DividerItemDecoration.HORIZONTAL))
recyclerView.addItemDecoration(new DividerItemDecoration(this,
                DividerItemDecoration.VERTICAL))
recyclerView.setLayoutManager(new GridLayoutManager(HomepageActivity.this,2));
recyclerView.setAdapter(imageAdapter);

single_item_homepage.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:foreground="?android:selectableItemBackground"
    android:orientation="vertical"
    android:padding="@dimen/fifteen_dp">

    <ImageView
        android:id="@+id/ivGraphItemThumb"
        android:layout_width="match_parent"
        android:layout_height="125dp"
        tools:src="@drawable/ic_recent_exce" />

    <TextView
        android:id="@+id/tvMenu"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:textColor="@color/black"
        android:textSize="@dimen/fifteen_sp"
        tools:text="Item 1" />
</LinearLayout>

Answer 2

添加以下代碼以設置RecylcerView的GridLayoutManager的分隔線。

recyclerView.addItemDecoration(new GridLayoutItemDecoration(2));

在GridLayoutItemDecoration類下面使用。

public class GridLayoutItemDecoration extends RecyclerView.ItemDecoration {
    private int space;

    public GridLayoutItemDecoration(int space) {
        this.space = space;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        int position = parent.getChildLayoutPosition(view);

        /// Only for GridLayoutManager 
        GridLayoutManager manager = (GridLayoutManager) parent.getLayoutManager();

        if (parent.getChildLayoutPosition(view) < manager.getSpanCount())
            outRect.top = space;

        if (position % 2 != 0) {
            outRect.right = space;
        }

        outRect.left = space;
        outRect.bottom = space;
    }
}

從single_item_homepage xml刪除CardView和根布局邊距並設置背景顏色（在您的情況下為白色）。

設置RecyclerView背景顏色（在您的情況下為灰色），它將顯示為分隔線的顏色。

Answer 3

如果您在drawVertical中使用childCount-1而在DividerItemDecoration中使用drawHorizo​​ntal，則它將不適用於GridLayoutManager。

我修改了DividerItemDecoration類，只添加了內部分隔符對GridLayoutManager的支持。 它還可以支持普通的LinearLayoutManager。

你可以嘗試一下。

MiddleDividerItemDecoration

https://gist.github.com/Veeyikpong/a376c6128e603b0dee316670a74b345b

如何使用？

GridLayoutManager

//MiddleDivideritemDecoration.ALL means both vertical and horizontal dividers
//You can also use MiddleDividerItemDecoration.VERTICAL / MiddleDividerItemDecoration.HORIZONTAL if you just want horizontal / vertical dividers
recyclerView.addItemDecoration(MiddleDividerItemDecoration(context!!, MiddleDividerItemDecoration.ALL))
recyclerView.layoutManager = GridLayoutManager(context!!, 3)
recyclerView.adapter = customAdapter

有關完整用法，請參閱https://gist.github.com/Veeyikpong/a376c6128e603b0dee316670a74b345b#gistcomment-2897799

編輯：這只適用於透明背景。