基本的gridview android问题。它不显示任何东西

Question

我目前正在制作具有自定义布局的基本网格视图。虽然我现在只在 gridview 中显示文本。我在网上遵循一些教程并一步一步地遵循一切，我没有从 android studio 得到任何错误，我运行它。但是当我运行它时，它只显示一个空白的白页。这次我确实初始化了适配器，但它仍然没有显示任何内容。帮助我错过了什么。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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="match_parent"
    android:orientation="horizontal"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/firsttext"
        android:layout_width="match_parent"
        android:layout_height="@dimen/ButtonSize"
        android:text="@string/hello"
        android:gravity="center"/>
    <GridView
        android:layout_below="@+id/firsttext"
        android:id="@+id/firstList"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:columnWidth="100dp"
        android:numColumns="auto_fit"
        android:stretchMode="columnWidth">
    </GridView>

</RelativeLayout>

gridlist.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/gridtext"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@string/hello"
        android:textSize="@dimen/ButtonSize" />
</RelativeLayout>

gridadapter.java

public class gridAdapter extends BaseAdapter {
    Context context;
    String[] names;
    LayoutInflater layoutInflater;

    public gridAdapter(Context context,String[] names) {
        this.context = context;
        this.names = names;
    }

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

    @Override
    public Object getItem(int position) {
        return names[position];
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        View gridView = convertView;
        if (convertView != null){
            layoutInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            gridView = layoutInflater.inflate(R.layout.gridlist,null);

        }

        TextView textView = (TextView)gridView.findViewById(R.id.gridtext);
        textView.setText(names[position]);
        return gridView;
    }
}

MainActivity.java

public class MainActivity extends AppCompatActivity {


    String[] Names = {"great","good","average","great","good","average","great","good","average","great","good","average","great","good","average","great","good","average"};
    GridView grid;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        grid = (GridView)findViewById(R.id.firstList);

        gridAdapter adapter = new gridAdapter(this,Names);
        grid.setAdapter(adapter);

    }


}

Answer 1

不要在您的网格列表中使用match_parent 和TextView 的layout_heiht 替换它wrap_content 并为您的TextView 设置特殊颜色，白色除外。

Answer 2

将此行更改为：在gridadapter中：

if (convertView == null) {
        layoutInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        gridView = layoutInflater.inflate(R.layout.gridlist, parent, false); 
}

Answer 3

在适配器中改变这个：

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        convertView= layoutInflater.inflate(R.layout.gridlist,null);
        TextView textView = (TextView)convertView.findViewById(R.id.gridtext);
        textView.setText(names[position]);
        return convertView;
    }

Answer 4

以后使用 RecyclerView 代替 GridView。您的问题是为 TextView 设置颜色，检查将 textColor 设置为黑色