九宫格

**在这次作业中老师要求我们做出手机中常用的九宫格界面，此时我们需要使用GridView和SimpleAdapter来实现手机界面的九宫格，看似很简单，做起来却并不是很容易。首先我们要打开一个空白布局，代码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:id="@+id/w"
    android:orientation="vertical"
tools:context="com.example.mpyypm.qwer.MainActivity">


</LinearLayout>

其效果如图：

**其次，我们来做出显示图片的代码运用ImageView，只需做出一张图片剩下的复制粘贴即可，图片的代码如下；

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="com.example.mpyypm.qwer.MainActivity">
<ImageView
    android:id="@+id/n"
    android:layout_width="100dp"
    android:layout_height="200dp">
    android:gravity="center"

</ImageView>

</LinearLayout>

**再其次，我们要使用GridView来实现九宫格的格式，代码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="com.example.mpyypm.qwer.MainActivity">
<GridView
    android:id="@+id/z"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    android:gravity="center"
    android:horizontalSpacing="20dp"
    android:numColumns="5"
    android:verticalSpacing="10dp">
</GridView>

</LinearLayout>

其实现效果如图：

第二部分就是Java部分的代码了：

public class MainActivity extends AppCompatActivity {
    private GridView gridView;
    private SimpleAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    gridView=(GridView) findViewById(R.id.gridview);
    adapter = new SimpleAdapter(
    this,
    getData(),
    R.layout.photo_item,
    new String[]{"imageview"},
    new int[]{R.id.imageview});


gridView=(GridView) findViewById(R.id.gridview);
gridView.setAdapter(adapter);




gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
    String data = (String) adapterView.getItemAtPosition(position);
    }
});

}

private List<HashMap<String, Object>> getData() {
List<HashMap<String, Object>> datas = new ArrayList<>();




HashMap<String, Object> data = new HashMap<>();



data.put("imageview", R.drawable.a);



datas.add(data);

data=new HashMap<>();
data.put("imageview", R.drawable.b);
datas.add(data);

data=new HashMap<>();
data.put("imageview", R.drawable.c);
datas.add(data);

data=new HashMap<>();
data.put("imageview", R.drawable.d);
datas.add(data);

data=new HashMap<>();
data.put("imageview", R.drawable.e);
datas.add(data);

data=new HashMap<>();
data.put("imageview", R.drawable.f);
datas.add(data);

data=new HashMap<>();
data.put("imageview", R.drawable.g);
datas.add(data);

data=new HashMap<>();
data.put("imageview", R.drawable.h);
datas.add(data);

data=new HashMap<>();
data.put("imageview", R.drawable.i);
datas.add(data);

return datas;

}
 }

即可得到想要的九宫格模板。