Android GridView无法填充Activity的解决办法

GridView相信也很常见，但是GridView有一个缺点就是无法控制整个GridView的高度，只能通过子view去控制其高度。
项目中往往会有这样需求，让一个Gridview铺满整个屏幕

关键点：
在GridView的adapter中对item高度进行计算，然后再设置。

核心代码：

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

        ViewHolder holder;

        if(convertView==null){
            convertView= LayoutInflater.from(context).inflate(R.layout.item_shmain ,parent ,false);
            holder=new ViewHolder();

            holder.itemIV= (ImageView) convertView.findViewById(R.id.iv_item);
            holder.itemTV= (TextView) convertView.findViewById(R.id.tv_item);

            convertView.setTag(holder);
        }else {
            holder= (ViewHolder) convertView.getTag();
        }

        holder.itemIV.setBackgroundResource(images[position]);
        holder.itemTV.setText(names[position]);

        LinearLayout.LayoutParams lp=new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                (CommonUtil.getDeviceHeight(context)-CommonUtil.getBarHeight(context))/3);
        convertView.setLayoutParams(lp);

        return convertView;
    }

这里设置高度是屏幕的高度减掉标题栏的高度，然后除以gridview的行数（这里直接写死 了3）.通过动态设置adapter的convertview的高度就实现了GridView填充整个屏幕。

最后贴出所有代码记录：

public class MainActivity extends AppCompatActivity {

    private GridView mGridView;

    private String[] itemName={"扫码安装" ,"扫码维修" ,"设备数据查询" ,"我的工作记录" ,"关于我们" ,"设置"};
    private int[] imgId={R.drawable.icon_sh_1 ,R.drawable.icon_sh_2 ,R.drawable.icon_sh_3 ,
            R.drawable.icon_sh_4 ,R.drawable.icon_sh_5 ,R.drawable.icon_sh_6};

    private SHGridAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);

        mGridView= (GridView) findViewById(R.id.gv_sh);

        mAdapter=new SHGridAdapter(this,itemName,imgId);
        mGridView.setAdapter(mAdapter);
    }

public class SHGridAdapter extends BaseAdapter{

    private Context context;

    private String[] names;
    private int[] images;

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

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

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

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

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

        ViewHolder holder;

        if(convertView==null){
            convertView= LayoutInflater.from(context).inflate(R.layout.item_shmain ,parent ,false);
            holder=new ViewHolder();

            holder.itemIV= (ImageView) convertView.findViewById(R.id.iv_item);
            holder.itemTV= (TextView) convertView.findViewById(R.id.tv_item);

            convertView.setTag(holder);
        }else {
            holder= (ViewHolder) convertView.getTag();
        }

        holder.itemIV.setBackgroundResource(images[position]);
        holder.itemTV.setText(names[position]);

        LinearLayout.LayoutParams lp=new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                (CommonUtil.getDeviceHeight(context)-CommonUtil.getBarHeight(context))/3);
        convertView.setLayoutParams(lp);

        return convertView;
    }

    class ViewHolder{

        private ImageView itemIV;
        private TextView itemTV;

    }

}

public class CommonUtil {

    public static int getDeviceHeight(Context context){

        WindowManager wm= (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);

        return wm.getDefaultDisplay().getHeight();

    }

    /**
     * 获取状态栏高度
     */
    public static int getBarHeight(Context context){
        Class<?> c = null;
        Object obj = null;
        Field field = null;
        int x = 0, sbar = 38;//默认为38，貌似大部分是这样的

        try {
            c = Class.forName("com.android.internal.R$dimen");
            obj = c.newInstance();
            field = c.getField("status_bar_height");
            x = Integer.parseInt(field.get(obj).toString());
            sbar = context.getResources().getDimensionPixelSize(x);

        } catch (Exception e1) {
            e1.printStackTrace();
        }
        return sbar;
    }

}

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:gravity="center"
    android:background="@drawable/bg_gridview"
    android:paddingTop="30dp"
    android:paddingBottom="30dp"
    >

    <ImageView
        android:id="@+id/iv_item"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:layout_centerHorizontal="true"
        android:background="@drawable/icon_sh_1"/>

    <TextView
        android:id="@+id/tv_item"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="扫码安装"
        android:gravity="center_horizontal"
        android:textSize="17sp"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        />
</LinearLayout>

这里每个gridview的边框效果是通过一个背景实现的（其实有缺陷，部分地方有重复）

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_pressed="true">
        <shape android:shape="rectangle">
            <stroke android:width="1.0px"
                android:color="#e12121"/>
            <gradient android:angle="270.0"
                android:endColor="#ffe8ecef"
                android:startColor="#ffe8ecef"/>
        </shape>
    </item>

    <item android:state_focused="true">
        <shape android:shape="rectangle">
            <shape android:shape="rectangle">
                <stroke android:width="1.0px"
                    android:color="#e12121"/>
                <gradient android:angle="270.0"
                    android:endColor="#ffe8ecef"
                    android:startColor="#ffe8ecef"/>
            </shape>
        </shape>
    </item>

    <item>
        <shape android:shape="rectangle">
        <gradient android:angle="270.0"
            android:endColor="#ffffffff"
            android:startColor="#ffffffff" />
        <stroke android:width="1.0px"
            android:color="#e12121" />
    </shape>
    </item>

</selector>

ok，代码很功能都很基础。感觉有用的朋友可以留言支持，一起进步！