Question

我根据需要定制了listview适配器。

我想要实现什么？

我的应用程序将通过外部阅读器发送serialno和

1。如果列表视图中已存在序列号，则与其关联的图像视图应更改。 2. 如果serialno不可用，则应在listview上添加（此部分已完成。）

现在我想检查列表视图中现有项目的序列号并更改其imageview。我怎么实现它？

此外，我想获得具有特定imageView的所有listview项目？

activity_scan.xml

<ListView
    android:id="@+id/scan_loc_list"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" >
</ListView>

activity_listview.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="82dp"
    android:padding="@dimen/activity_horizontal_margin"
    android:background="?android:selectableItemBackground"
    android:orientation="vertical"
    android:descendantFocusability="blocksDescendants"
    >

    <ImageView
        android:id="@+id/scan_img_view"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_centerVertical="true"
        android:layout_alignParentStart="true"/>

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toEndOf="@+id/scan_img_view"
        android:layout_marginStart="@dimen/activity_horizontal_margin"
        android:orientation="vertical">

        <TextView
            android:id="@+id/scan_serial"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#000"
            android:textSize="18sp"/>       

    </LinearLayout>

</RelativeLayout>

ScanItem.Java

public class ScanItem {

    private int imageId;    
    private String serial;

    // Getter and Setter Methods 
    ............

}

ScanAdapter.java

public class ScanAdapter extends ArrayAdapter<ScanItem> {

    Context context;

    public ScanViewAdapter(Context context, int resourceId,List<ScanItem> items) {
        super(context, resourceId, items);
        this.context = context;
    }

    private class ViewHolder {
        ImageView imageView;
        TextView txtSerial;
    }


    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        ScanItem rowItem = getItem(position);

        LayoutInflater mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.activity_listview, null);
            holder = new ViewHolder();
            holder.txtSerial = (TextView) convertView.findViewById(R.id.scan_serial);
            holder.imageView = (ImageView) convertView.findViewById(R.id.scan_img_view);
            convertView.setTag(holder);
        } else
            holder = (ViewHolder) convertView.getTag();

        holder.txtSerial.setText(rowItem.getSerial());
        holder.imageView.setImageResource(rowItem.getImageId());
        return convertView;
    }


}

MainActivity.java

ScanAdapter assetListAdapter = new ScanAdapter(getActivity(), R.layout.activity_listview, items);  // items contains array of ScanItem objects
ListView androidListView = (ListView) getView().findViewById(R.id.scan_loc_list);
androidListView.setAdapter(assetListAdapter);

Answer 1

我自己找到了答案

int count = androidListView.getAdapter().getCount();

        String[] listData = new String[count];
        for (int i = 0; i < count; i++) {
            ScanItem sc = (ScanItem) androidListView.getAdapter().getItem(i);
            // sc will have all the required data
        }

获取和更改listview适配器项而不使用onclick处理程序

1 个答案: