java - 我无法在 setOnClickListener() 中 Toast 变量值

Question

我想在 setOnClickListener() 中显示来自 imageAndTexts1.get(position).getUrl() 的变量值。

这是我的代码

public class RssReaderListAdapter extends ArrayAdapter<RssFeedStructure> {
    List<RssFeedStructure> imageAndTexts1 = null;

    public RssReaderListAdapter(Activity activity,
            List<RssFeedStructure> imageAndTexts) {
        super(activity, 0, imageAndTexts);
        imageAndTexts1 = imageAndTexts;


        // Permission StrictMode
        if (android.os.Build.VERSION.SDK_INT > 9) {
            StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy);
        }
    }

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

        Activity activity = (Activity) getContext();
        LayoutInflater inflater = activity.getLayoutInflater();

        View rowView = inflater.inflate(R.layout.rssfeedadapter_layout, null);
        TextView textView = (TextView) rowView.findViewById(R.id.feed_text);
        TextView timeFeedText = (TextView) rowView
                .findViewById(R.id.feed_updatetime);
        ImageView imageView = (ImageView) rowView.findViewById(R.id.feed_image);
        try {

            Log.d("rssfeed", "imageAndTexts1.get(position).getImgLink() :: "
                    + imageAndTexts1.get(position).getImgLink() + " :: "
                    + imageAndTexts1.get(position).getTitle()+ " :: "
                    + imageAndTexts1.get(position).getUrl());
            textView.setText(imageAndTexts1.get(position).getTitle());
            SpannableString content = new SpannableString(imageAndTexts1.get(
                    position).getPubDate());
            content.setSpan(new UnderlineSpan(), 0, 13, 0);

            timeFeedText.setText(content);

             textView.setOnClickListener(new View.OnClickListener() {

                    private Activity context;

                    @Override
                    public void onClick(View v) {

Toast.makeText(context.getApplicationContext(), imageAndTexts1.get(position).getUrl().toString(), Toast.LENGTH_SHORT).show();


               /*          String url = imageAndTexts1.get(position).getUrl().toString();
                         Intent i = new Intent(Intent.ACTION_VIEW);
                         i.setData(Uri.parse(url));
                         context.startActivity(i); */
                    }
                }); 

当我运行此代码时，它可以显示 Log.d() 中的文本。但是当我在模拟器中单击 textView 时，它会显示这样的错误。

07-02 09:49:10.844: E/AndroidRuntime(968): FATAL EXCEPTION: main
07-02 09:49:10.844: E/AndroidRuntime(968): java.lang.NullPointerException
07-02 09:49:10.844: E/AndroidRuntime(968):  at com.amit.adapter.RssReaderListAdapter$1.onClick(RssReaderListAdapter.java:84)
07-02 09:49:10.844: E/AndroidRuntime(968):  at android.view.View.performClick(View.java:4204)
07-02 09:49:10.844: E/AndroidRuntime(968):  at android.view.View$PerformClick.run(View.java:17355)
07-02 09:49:10.844: E/AndroidRuntime(968):  at android.os.Handler.handleCallback(Handler.java:725)
07-02 09:49:10.844: E/AndroidRuntime(968):  at android.os.Handler.dispatchMessage(Handler.java:92)
07-02 09:49:10.844: E/AndroidRuntime(968):  at android.os.Looper.loop(Looper.java:137)
07-02 09:49:10.844: E/AndroidRuntime(968):  at android.app.ActivityThread.main(ActivityThread.java:5041)
07-02 09:49:10.844: E/AndroidRuntime(968):  at java.lang.reflect.Method.invokeNative(Native Method)
07-02 09:49:10.844: E/AndroidRuntime(968):  at java.lang.reflect.Method.invoke(Method.java:511)
07-02 09:49:10.844: E/AndroidRuntime(968):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-02 09:49:10.844: E/AndroidRuntime(968):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-02 09:49:10.844: E/AndroidRuntime(968):  at dalvik.system.NativeStart.main(Native Method)

在log.d()中它可以无错误地显示文本。但是在 setOnClickListener() 中，当我单击列表中的文本时，它显示 NullPointerException。请帮助我。

Answer 1

您正在使用context，此时它将为null，因为您没有分配给它。

您应该能够通过 getview 方法使用 activity。即用 activity 替换监听器中的 context。