Android Java 使用cardview来显示gridview的item

问题描述

大家好，我想用 GridView 显示一些显示字符串数组内容的项目。这是我想设置为项目的 CardView：

所以当我点击一个按钮时，电影类型选择的布局变得可见，我设置了一个适配器：

cTBtn.setonClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                postaCardVIew.setVisibility(View.GONE);
                cT.setVisibility(View.VISIBLE);

                GridView simpleGridView = findViewById(R.id.simpleGridView);

                String genrelist[] = {"Commedia","Animazione","Anime","Avventura","Azione","Biografico","Documentario","Drammatico","Fantascienza","Fantasy","Guerra","Horror","Musical","Storico","Thriller","Western","Giallo","Sentimentale",};

                final ArrayAdapter<String> adapter = new ArrayAdapter<String> (posta.this,android.R.layout.simple_list_item_1,genrelist);
                simpleGridView.setAdapter(adapter);
}

但这就是我得到的：

不过我想夸大这个布局：

<?xml version="1.0" encoding="utf-8"?>

    <androidx.cardview.widget.CardView
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="150dp"
        android:layout_height="150dp"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        app:cardCornerRadius="30dp"
        android:layout_marginLeft="5dp"
        android:layout_marginTop="5dp"
        >
        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">
        <TextView
            android:id="@+id/type"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Type"
            android:layout_centerInParent="true"
            android:textSize="20dp"
            android:textStyle="bold"
            />
    
        </RelativeLayout>
    
    
</androidx.cardview.widget.CardView>

得到这样的东西：

谁能帮我弄清楚如何扩大所需的布局？

解决方法

为了使用自定义项目布局，您需要创建一个从 BaseAdapter 或 ArrayAdapter 扩展的自定义适配器

然后在 getView() 方法中膨胀并构建您的项目布局：

public class CustomAdapter extends BaseAdapter {

    String genrelist[] = {"Commedia","Animazione","Anime","Avventura","Azione","Biografico","Documentario","Drammatico","Fantascienza","Fantasy","Guerra","Horror","Musical","Storico","Thriller","Western","Giallo","Sentimentale",};


    // create a new ImageView for each item referenced by the Adapter
    public View getView(int position,View convertView,ViewGroup parent) {

        ViewHolder holder;

        if (convertView == null) {
            convertView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item,parent,false);
            holder = new ViewHolder();
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }
        holder.title = convertView.findViewById(R.id.type);
        holder.title.setText(genrelist[position]);
        return convertView;
    }

    static class ViewHolder {
        TextView title;
    }



    public int getCount() {
        return genrelist.length;
    }

    public Object getItem(int position) {
        return null;
    }

    public long getItemId(int position) {
        return 0;
    }
}

并将其用作 GridView 适配器：

cTBtn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        postaCardVIew.setVisibility(View.GONE);
        cT.setVisibility(View.VISIBLE);

        GridView simpleGridView = findViewById(R.id.simpleGridView);

        simpleGridView.setAdapter(new CustomAdapter());
    }
});

我不得不操纵边距和关心的宽度，并用 CardView 包裹 FrameLayout 以强制卡片之间的边距：

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginHorizontal="4dp"
    android:layout_marginVertical="4dp">

    <androidx.cardview.widget.CardView xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="120dp"
        android:layout_height="120dp"
        app:cardCornerRadius="30dp">

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

            <TextView
                android:id="@+id/type"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:text="Type: 1"
                android:textSize="18sp"
                android:textStyle="bold" />

        </RelativeLayout>

    </androidx.cardview.widget.CardView>
</FrameLayout>

结果：