Android BaseAdapter用法 _BaseAdapte

少年辛苦终身事，莫向光阴惰寸功。这篇文章主要讲述Android BaseAdapter用法相关的知识，希望能为你提供帮助。
BaseAdapter 适配器

BaseAdapter是一个抽象类，因此要写自已的适配器，段继承此类，并实现以下方法：
@Override
public int getCount() {return 0; }
@Override

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

public long getItemId(int position) { return 0; }
@Override
public View getView(int position, View convertView, ViewGroup parent) {return null; }

Demo:
描述：用ListView,BaseAdapter实现多个用户信息展示，根据用户性不同显示不同的性别图片（如下图）

文章图片

代码如下：

主界面布局文件：activity_main < ?xml version="1.0" encoding="utf-8"?> < RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.zy.baseadapter.MainActivity"> < ListView android:id="@+id/user_list_view" android:layout_width="match_parent" android:layout_height="match_parent"> < /ListView> < /RelativeLayout>

//item_user.xml 布局文件< ?xml version="1.0" encoding="utf-8"?> < LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> < ImageView android:scaleType="centerInside" android:id="@+id/iv_user_img" android:layout_width="60dp" android:layout_height="60dp" /> < TextView android:id="@+id/tv_user_name" android:layout_width="wrap_content" android:layout_height="wrap_content" /> < TextView android:id="@+id/tv_user_age" android:layout_width="wrap_content" android:layout_height="wrap_content" /> < TextView android:id="@+id/tv_user_sex" android:layout_width="wrap_content" android:layout_height="wrap_content" /> < /LinearLayout>

图片文件

文章图片

public class MainActivity extends AppCompatActivity {List< UserInfo> userInfos = new ArrayList< > (); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //用户数据 for (int i = 0; i < 30; i++){ UserInfo userInfo = new UserInfo(); userInfo.userName = "张" + i; userInfo.userAge = i; userInfo.userSex = i%2 == 0?"男":"女"; userInfos.add(userInfo); } //listView ListView listView = (ListView) findViewById(R.id.user_list_view); //实例化一个适配器 UserInfoListAdapter userInfoListAdapter = new UserInfoListAdapter(); listView.setAdapter(userInfoListAdapter); } //点击屏幕跳转到第二个Activity （点击事件） //@Override //public boolean onTouchEvent(MotionEvent event) { //int action = event.getAction(); //if(action == MotionEvent.ACTION_DOWN){ //Intent intent = new Intent(this,MenuActiviy.class); //startActivity(intent); //} //return false; //}class UserInfoListAdapter extends BaseAdapter{@Override public int getCount() { return userInfos.size(); }@Override public Object getItem(int position) { return userInfos.get(position); }@Override public long getItemId(int position) { return position; }@Override public View getView(int position, View convertView, ViewGroup parent) { View itemRootView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_user,null); TextView userNameView = (TextView) itemRootView.findViewById(R.id.tv_user_name); userNameView.setText(userInfos.get(position).userName); TextView userAgeView = (TextView) itemRootView.findViewById(R.id.tv_user_age); userAgeView.setText(userInfos.get(position).userAge + ""); TextView userSexView = (TextView) itemRootView.findViewById(R.id.tv_user_sex); userSexView.setText(userInfos.get(position).userSex); ImageView imageView = (ImageView) itemRootView.findViewById(R.id.iv_user_img); if(userInfos.get(position).userSex.equals("男")){ imageView.setBackgroundResource(R.drawable.man); }else if(userInfos.get(position).userSex.equals("女")){ imageView.setBackgroundResource(R.drawable.woman); } return itemRootView; } } class UserInfo{ private String userName; private int userAge; private String userSex; } }

【Android BaseAdapter用法】