Codenameone 呈现genericlistrenderer时出现空指针异常
***当Iam从UI builder呈现res文件时，Iam尝试显示填充有图像和文本的列表Iam获取空指针异常。代码如下： @凌驾 表格f之前的受保护空白{Codenameone 呈现genericlistrenderer时出现空指针异常,codenameone,Codenameone,***当Iam从UI builder呈现res文件时，Iam尝试显示填充有图像和文本的列表Iam获取空指针异常。代码如下： @凌驾 表格f之前的受保护空白{ super.beforeMain(f); final List list = findList(f); Component selected = createContainer(fetchResourceFile(), "Renderer"); Component unselected = createContainer(
super.beforeMain(f);
final List list = findList(f);
Component selected = createContainer(fetchResourceFile(), "Renderer");
Component unselected = createContainer(fetchResourceFile(), "Renderer");
System.out.println(selected.getName());
list.setRenderer(new GenericListCellRenderer(selected, unselected) {
public Component getListCellRendererComponent(List list, Object value, int index, boolean isSelected) {
if ((index + 1) >= list.size()) {
fetchMore(list);
}
return super.getListCellRendererComponent(list, value, index, isSelected);
}
private void fetchMore(final List list) {
// TODO Auto-generated method stub
// TODO Auto-generated method stub
NetworkManager networkManager = NetworkManager.getInstance();
networkManager.start();
networkManager.addErrorListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
NetworkEvent n = (NetworkEvent) evt;
n.getError().printStackTrace();
}});
ConnectionRequest request = new ConnectionRequest() {
String array[] ;
String images[];
//StringBuffer sb = new StringBuffer();
Hashtable h;
Vector tweets;
// @Override
protected void postResponse() {
//cmp.setModel(new com.codename1.ui.list.DefaultListModel(array));
}
protected void readResponse(InputStream input) throws IOException {
Result result = Result.fromContent(input, Result.XML);
array = result.getAsStringArray("/music[1]//thumb_url");
int count = list.size();
for (int i = 0; i < array.length; i++) {
// Hashtable tweet = (Hashtable)tweets.elementAt(i);
list.addItem(array[i]);
addAvatar(list, array[i], count + i);
}
System.out.println(""+array.length);
}
private void addAvatar(List list, String array, int i) {
// TODO Auto-generated method stub
//String url = (String)array.get("profile_image_url");
//String user = (String)array.get("from_user");
// if (array == null || array.startsWith("http:") == false) {
// ImageDownloadService doesn't support HTTPS at moment
// return;
//}
ImageDownloadService ids = new ImageDownloadService(array, list, i, "avatar");
ids.setDuplicateSupported(true);
NetworkManager.getInstance().addToQueue(ids);
ImageDownloadService.createImageToStorage(array, list, i, "avatar", "-avatar",
new Dimension(48, 48));
}
protected void handleException(Exception err) {
//An error occured - show a message:
Dialog.show("Alert", "Are you connected to the internet? Check your connection", "Ok", null);
}
};
request.setUrl("http://api.androidhive.info/music/music.xml"); //servlet calling
request.setPost(false);
//infiniteProgress prog=
InfiniteProgress prog=new InfiniteProgress();
Dialog dlg=prog.showInifiniteBlocking();
request.setDisposeOnCompletion(dlg);
networkManager.addToQueueAndWait(request);
}
}); }
}；*在不突出显示实际第117行的情况下指定一个异常不是很有帮助 您正在执行来自渲染器的网络请求，这可能不是一个好方法，每分钟会被调用数千次。您应该使用该模型实现延迟数据获取，例如