GridView的简单使用

##此方法是使用自带适配器实现

gridview.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <ImageView
        android:id="@+id/img1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/text1"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:gravity="center_horizontal"
       />
</LinearLayout>
</android.support.constraint.ConstraintLayout>

activity.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
tools:context=".MainActivity">
    <!--
    android:numColumns="3"三列
     android:stretchMode="spacingWidthUniform"
     加入参数后gridview内的组件长宽需要设定具体值，否指无法正常显示
                            columnWidth 如果列有空闲空间就加宽列
                            spacingWidth 如果列有空闲空间就加宽各列间距
                            none 没有任何动作
                            spacingWidthUniform 平均分配空间
    -->
    <GridView
        android:id="@+id/gv1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:numColumns="3"
    >

    </GridView>
</android.support.constraint.ConstraintLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {
    private GridView gridView;
    private SimpleAdapter adapter;
    private List<Map<String,Object>>data;
    String[] from={"img","text"};
    int[] to={R.id.img1,R.id.text1};
    private int img1=R.drawable.tou; //此为图片地址
    private String text1[]={"1","2","3","4"};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
        data=new ArrayList<Map<String,Object>>();
        for(int i=0;i<text1.length;i++){
            Map<String,Object>map=new HashMap<>();
            map.put("img",img1);
            map.put("text",text1[i]);
            data.add(map);
        }
        gridView=findViewById(R.id.gv1);
        //   public SimpleAdapter(Context context, List<? extends Map<String, ?>> data,
        //            @LayoutRes int resource, String[] from, @IdRes int[] to)
        // 上下文，一个List里面含有Map，来源的第三个xml，map里面的String标签数列，要一一对一个，
        // 里面的组件数列
        adapter=new SimpleAdapter(this,data,R.layout.gridview,from,to);
        gridView.setAdapter(adapter);
    }