Question

Android编程相当新，并且在单击按钮时无法更改字符串值“channel”。有问题试图关闭onCreate但它似乎只让我在活动结束时关闭它。我收到'token“}的错误。”请删除'如果我试图在其他地方关闭它。我很难试图绕过这个，即使它可能非常简单。

public class MainActivity extends Activity { 

    String channel = "bbc1";

    // This method creates main application view
    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState); 
        // Set view
        setContentView(R.layout.main);
        final ViewSwitcher switcher = (ViewSwitcher)findViewById(R.id.ViewSwitcher1);
        Button bbcButton = (Button) findViewById(R.id.bbcButton);
        Button bbc2Button = (Button) findViewById(R.id.bbc2Button);



        bbcButton.setOnClickListener(new OnClickListener(){
            public void onClick(View v) {
                channel = "bbc1";
                switcher.showNext();    
            }   
        });


        bbc2Button.setOnClickListener(new OnClickListener(){
            public void onClick(View v) {
                channel = "bbc2";
                switcher.showNext();
            }
        });


        try{
            // This line creates RSS reader
            RssReader rssReader = new RssReader("http://bleb.org/tv/data/rss.php?ch="+channel+"&day=0");

            // This line gets a ListView from main view
            ListView tvItems = (ListView) findViewById(R.id.listMainView);

            // This line creates a list adapter
            ArrayAdapter<RssItem> adapter = new ArrayAdapter<RssItem>(this,android.R.layout.simple_list_item_1, rssReader.getItems());

            // This line sets list adapter for the ListView
            tvItems.setAdapter(adapter);


        } catch (Exception e) {
            Log.e("Tv RSS Reader", e.getMessage());
        }

    }
}

Answer 1

我猜你想按下按钮时想要改变RSS提要。但是，由于您在onCreate中获取RSS信息，即使按下按钮，也不会更新数据。但是你正在改变字符串通道的值。

onCreate仅在您创建活动时调用一次！

尝试将try-statement移动到单独的方法中，并在两个onClickListeners中调用此方法。

    bbc2Button.setOnClickListener(new OnClickListener(){
        public void onClick(View v) {
            channel = "bbc2";
            updateRSS();
            switcher.showNext();
        }
    });

    public void updateRSS(){
        try{
           // This line creates RSS reader
           RssReader rssReader = new RssReader("http://bleb.org/tv/data/rss.php?ch="+channel+"&day=0");

           // This line gets a ListView from main view
           ListView tvItems = (ListView) findViewById(R.id.listMainView);

           // This line creates a list adapter
           ArrayAdapter<RssItem> adapter = new ArrayAdapter<RssItem>(this,android.R.layout.simple_list_item_1, rssReader.getItems());

           // This line sets list adapter for the ListView
           tvItems.setAdapter(adapter);


        } catch (Exception e) {
           Log.e("Tv RSS Reader", e.getMessage());
    }

在OnClick中更改字符串值

1 个答案: