Android ListView

Android ListView 是一個包含一組項目并在可滾動列表中顯示的視圖。愛掏網(wǎng) - it200.comListView通過導入android.widget.ListView類來實現(xiàn)。愛掏網(wǎng) - it200.comListView是一個默認可滾動的視圖，不使用其他滾動視圖。愛掏網(wǎng) - it200.com

ListView使用Adapter類將數(shù)據(jù)源（如字符串數(shù)組、數(shù)組、數(shù)據(jù)庫等）的內(nèi)容添加到ListView中。愛掏網(wǎng) - it200.comAdapter在AdapterView（如ListView、ScrollView等）和其他視圖之間建立數(shù)據(jù)橋接。愛掏網(wǎng) - it200.com

ListView的示例

讓我們來實現(xiàn)一個簡單的listview示例。愛掏網(wǎng) - it200.com

listview項目的結(jié)構(gòu)

activity_main.xml

首先，我們需要從調(diào)色板中拖放ListView組件到activity_main.xml文件中。愛掏網(wǎng) - it200.com

文件：activity_main.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="listview.example.com.listview.MainActivity">

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"
         />
</android.support.constraint.ConstraintLayout>

在layout文件夾中創(chuàng)建一個名為mylist.xml的額外文件，其中包含在listview中顯示的視圖組件。愛掏網(wǎng) - it200.com

mylist.xml

文件：mylist.xml

<?xml version="1.0" encoding="utf-8"?>

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/textView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Medium Text"
    android:textStyle="bold"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:layout_marginLeft="10dp"
    android:layout_marginTop="5dp"
    android:padding="2dp"
    android:textColor="#4d4d4d"
     />

現(xiàn)在通過創(chuàng)建string-array將數(shù)據(jù)列表放入strings.xml文件中。愛掏網(wǎng) - it200.com

strings.xml

文件:strings.xml

<resources>
    <string name="app_name">ListView</string>
    <string-array name="array_technology">
        <item>Android</item>
        <item>Java</item>
        <item>Php</item>
        <item>Hadoop</item>
        <item>Sap</item>
        <item>Python</item>
        <item>Ajax</item>
        <item>C++</item>
        <item>Ruby</item>
        <item>Rails</item>
        <item>.Net</item>
        <item>Perl</item>
    </string-array>
</resources>

活動類

在Java類中，我們需要使用listview的setAdapter()方法向listview添加適配器。愛掏網(wǎng) - it200.com

文件：MainActivity.java

package listview.example.com.listview;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    ListView listView;
    TextView textView;
    String[] listItem;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView=(ListView)findViewById(R.id.listView);
        textView=(TextView)findViewById(R.id.textView);
        listItem = getResources().getStringArray(R.array.array_technology);
        final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, android.R.id.text1, listItem);
        listView.setAdapter(adapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
                // TODO Auto-generated method stub
                String value=adapter.getItem(position);
                Toast.makeText(getApplicationContext(),value,Toast.LENGTH_SHORT).show();

            }
        });
    }
}

輸出