Android_ListView简单例子
ListView是Android软件开发中非常重要组件之一,基本上是个软件基本都会使用ListView ,今天我通过一个demo来教大家怎么样使用ListView组件
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" 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.example.asynctask.MainActivity" > <TextView android:id="@+id/textView1" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hello_world" /> <Button android:id="@+id/Button" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/textView1" android:text="按钮" /> <!-- ListView 由item.xml里的TextView给值 。--> <ListView android:id="@+id/listView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/Button" /> </RelativeLayout>
效果图:
上下两个xml文件要结合使用。 item.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" > <!-- 下面两个是用来给 activity_main.xml里的ListView赋值,--> <TextView android:id="@+id/Textviewname" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_weight="1" android:text="1" /> <TextView android:id="@+id/Textviewage" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_weight="1" android:text="2" /> </LinearLayout>
效果图:
java代码:
MainActivity.java
package com.example.asynctask; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.view.View.OnClickListener; import android.widget.BaseAdapter; import android.widget.Button; import android.widget.ListView; import android.widget.TextView; public class MainActivity extends Activity { private TextView tv1;//item.xml里的TextView:Textviewname private TextView tv2;//item.xml里的TextView:Textviewage private Button bt;//activity_main.xml里的Button private ListView lv;//activity_main.xml里的ListView private BaseAdapter adapter;//要实现的类 private List<User> userList = new ArrayList<User>();//实体类 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); bt = (Button) findViewById(R.id.Button); lv = (ListView) findViewById(R.id.listView1); //模拟数据库 for (int i = 0; i < 5; i++) { User ue = new User();//给实体类赋值 ue.setName("小米"+i); ue.setAge("18"); userList.add(ue); } /* bt.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { } });*/ adapter = new BaseAdapter() { @Override public int getCount() { // TODO Auto-generated method stub return userList.size();//数目 } @Override public View getView(int position, View convertView, ViewGroup parent) { LayoutInflater inflater = MainActivity.this.getLayoutInflater(); View view; if (convertView==null) { //因为getView()返回的对象,adapter会自动赋给ListView view = inflater.inflate(R.layout.item, null); }else{ view=convertView; Log.i("info","有缓存,不需要重新生成"+position); } tv1 = (TextView) view.findViewById(R.id.Textviewname);//找到Textviewname tv1.setText(userList.get(position).getName());//设置参数 tv2 = (TextView) view.findViewById(R.id.Textviewage);//找到Textviewage tv2.setText(userList.get(position).getAge());//设置参数 return view; } @Override public long getItemId(int position) {//取在列表中与指定索引对应的行id return 0; } @Override public Object getItem(int position) {//获取数据集中与指定索引对应的数据项 return null; } }; lv.setAdapter(adapter);
//获取当前ListView点击的行数,并且得到该数据
}
}
//获取当前ListView点击的行数,并且得到该数据 lv.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { tv1 = (TextView) view.findViewById(R.id.Textviewname);//找到Textviewname str = tv1.getText().toString();//得到数据 Toast.makeText(MainActivity.this, "" + str, Toast.LENGTH_SHORT).show();//显示数据 Intent it = new Intent(MainActivity.this, list0.class); // Bundle b = new Bundle(); b.putString("we",str); //string // b.putSerializable("dd",str); // it.putExtra("str_1",str); it.putExtras(b); startActivity(it); } });
实体类:
package com.example.asynctask; public class User { private String name; private String age; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } @Override public String toString() { return "User [name=" + name + ", age=" + age + "]"; } }
最后结果: