Question

嗨同志我想在段落输出yu date（13.4.2014）：

主要

public class MainActivity extends Activity implements OnItemClickListener {

public static final String[] titles = new String[] { "Strawberry",
        "Banana", "Orange", "Mixed" };



public static final Integer[] images = { R.drawable.news_icon_1,
        R.drawable.news_icon_2, R.drawable.news_icon_1, R.drawable.news_icon_2 };

ListView listView;
List<RowItem> rowItems;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    rowItems = new ArrayList<RowItem>();
    for (int i = 0; i < titles.length; i++) {
        RowItem item = new RowItem(images[i], titles[i], new GregorianCalendar(2011, 11, i).getTime());
        rowItems.add(item);
    }

    listView = (ListView) findViewById(R.id.list);
    CustomListViewAdapter adapter = new CustomListViewAdapter(this,
            R.layout.list_item, rowItems);
    listView.setAdapter(adapter);
    listView.setOnItemClickListener(this);
}


public void onItemClick(AdapterView<?> parent, View view, int position,
                        long id) {
    Toast toast = Toast.makeText(getApplicationContext(),
            "Item " + (position + 1) + ": " + rowItems.get(position),
            Toast.LENGTH_SHORT);
    toast.setGravity(Gravity.BOTTOM|Gravity.CENTER_HORIZONTAL, 0, 0);
    toast.show();
}

}

CustomListViewAdapter

public class CustomListViewAdapter extends ArrayAdapter {

Context context;


public CustomListViewAdapter(Context context, int resourceId,
                             List<RowItem> items) {
    super(context, resourceId, items);

    this.context = context;
}

/*private view holder class*/
private class ViewHolder {
    ImageView imageView;
    TextView txtTitle;
    TextView txtDesc;
}

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

    LayoutInflater mInflater = (LayoutInflater) context
            .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
    if (convertView == null) {
        convertView = mInflater.inflate(R.layout.list_item, null);
        holder = new ViewHolder();
        holder.txtDesc = (TextView) convertView.findViewById(R.id.desc);
        holder.txtTitle = (TextView) convertView.findViewById(R.id.title);
        holder.imageView = (ImageView) convertView.findViewById(R.id.icon);
        convertView.setTag(holder);
    } else
        holder = (ViewHolder) convertView.getTag();

    holder.txtDesc.setText((CharSequence) rowItem.getPostDate());
    holder.txtTitle.setText(rowItem.getTitle());
    holder.imageView.setImageResource(rowItem.getImageId());

    return convertView;
}
}

RowItem

public class RowItem {
private int imageId;
private String title;
private Date postDate;

public RowItem(int imageId, String title, Date postDate) {
    this.imageId = imageId;
    this.title = title;
    this.postDate = postDate;
}
public int getImageId() {
    return imageId;
}
public void setImageId(int imageId) {
    this.imageId = imageId;
}
public Date getPostDate() {
    return postDate;
}

public void setPostDate(Date postDate) {
    this.postDate = postDate;
}

public String getTitle() {
    return title;
}
public void setTitle(String title) {
    this.title = title;
}
@Override
public String toString() {
    return title + "\n" + postDate;
}

}

我收到错误：

04-13 07：42：13.559 862-862 / com.example.listview E / AndroidRuntime：FATAL EXCEPTION：main java.lang.ClassCastException：java.util.Date无法强制转换为java.lang.CharSequence

为什么？，以及如何约会？

Answer 1

你有

holder.txtDesc.setText((CharSequence) rowItem.getPostDate());

您正在向Date投射CharacterSequence。 setText将CharacterSequence作为参数。您需要做的是将日期转换为字符串，然后将其设置为textview

Convert java.util.Date to String

Format formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String datestring = formatter.format(rowItem.getPostDate());
holder.txtDesc.setText(datestring);

自定义ListView（数据）

1 个答案: