Android:控件Spinner实现下拉列表

2021-09-24 12:27:21 浏览数 (1)

这里主要介绍两种Spinner: 1.添加系统默认ArrayAdapter样式 2.采用之定义SpinnerAdapter样式 先看效果图:

首先看看自定义的SpinnerAdapter: 我门在这里借用下https://blog.csdn.net/wu_lai_314/article/details/24520249的定义

代码语言:javascript复制
class SpinnerAdapter extends ArrayAdapter<String> {

    Context context;

    String[] items = new String[] {};

    public SpinnerAdapter(final Context context,
                          final int textViewResourceId, final String[] objects) {
        super(context, textViewResourceId, objects);
        this.items = objects;
        this.context = context;
    }

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

        if (convertView == null) {
            LayoutInflater inflater = LayoutInflater.from(context);
            convertView = inflater.inflate(
                    android.R.layout.simple_spinner_item, parent, false);
        }

        TextView tv = (TextView) convertView
                .findViewById(android.R.id.text1);
        tv.setText(items[position]);
        tv.setGravity(Gravity.CENTER);
        tv.setTextColor(Color.BLUE);
        tv.setTextSize(30);
        return convertView;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            LayoutInflater inflater = LayoutInflater.from(context);
            convertView = inflater.inflate(
                    android.R.layout.simple_spinner_item, parent, false);
        }

        TextView tv = (TextView) convertView
                .findViewById(android.R.id.text1);
        tv.setText(items[position]);
        tv.setGravity(Gravity.CENTER);
        tv.setTextColor(Color.BLUE);
        tv.setTextSize(30);
        return convertView;
    }
}

MainActivity很简单 就两个Spinner基本创建:

代码语言:javascript复制
public class MainActivity extends Activity {
    //存放系统自带版本adapter的Spinner
    Spinner spinner_initially ;
    //存放自定义adapter的Spinner
    Spinner spinner_personal ;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取界面布局文件中的Spinner组件
        spinner_initially = (Spinner) findViewById(R.id.spinner_initially);
        String[] arr_initially = new String[]{
                "猫猫","狗狗","仓鼠"
        };
        //创建 ArrayAdapter对象
        ArrayAdapter<String> adapter_initially = new ArrayAdapter<>(this,android.R.layout.simple_list_item_multiple_choice,arr_initially);
        //为spinner设置adapter
        spinner_initially.setAdapter(adapter_initially);

        //获取界面布局文件中的Spinner组件
        spinner_personal = (Spinner) findViewById(R.id.spinner_personal);
        String[] arr_personaldesign = new String[]{
                "猫猫","狗狗","仓鼠"
        };
        //创建 ArrayAdapter对象
        SpinnerAdapter adapter_personal_design = new SpinnerAdapter(this,android.R.layout.simple_list_item_multiple_choice,arr_personaldesign);
        //为spinner设置adapter
        spinner_personal.setAdapter(adapter_personal_design);
    }
}

然后就是布局,依然是无脑定义就好:

代码语言:javascript复制
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    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:orientation="vertical" >
    <!--定义了一个 Spinner组件-->
    <!--指定组件的数组-->
    <Spinner
        android:id="@ id/spinner_initially"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:entries="@array/sex"
        android:prompt="@string/sex_user_tip"
        android:scrollbarSize="30sp"/>

    <android.support.v7.widget.AppCompatSpinner
        android:id="@ id/spinner_personal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:prompt="@string/sex_roommates_tip"
        android:scrollbarSize="30sp"/>
</LinearLayout>

最后就是下拉选项的引用了 在values里建一个自定义xml就行 这里是/values/chooseArrays

代码语言:javascript复制
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="sex">
        <item>男孩</item>
        <item>女孩</item>
        <item>荷兰猪</item>
    </string-array>
</resources>

因为采用默认ArrayAdapter由很多限制 掌握了自定义的方法, 只要设计能力够强就可以做出各种酷炫界面

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