Android:访问OnClickListener中的视图元素

Question

我有一个Fragment容器和片段外的一些按钮,它们与片段的内容相互作用.当我点击按钮时,我需要获取文本元素内的信息.这就是我现在所拥有的,但它不起作用.代码来自片段寻呼机演示.

Button bm = (Button) findViewById(R.id.bm);
bm.setOnClickListener(new OnClickListener() {
  public void onClick(View v) {
    EditText editTextIn1 = (EditText) v.findViewById(R.id.editTextIn1);
  }
});

编辑我使用这个示例:

http://developer.android.com/reference/android/support/v13/app/FragmentStatePagerAdapter.html

public class FragmentStatePagerSupport extends FragmentActivity {
    static final int NUM_ITEMS = 10;

    MyAdapter mAdapter;

    ViewPager mPager;

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

        mAdapter = new MyAdapter(getSupportFragmentManager());

        mPager = (ViewPager)findViewById(R.id.pager);
        mPager.setAdapter(mAdapter);

        // Watch for button clicks.
        Button button = (Button)findViewById(R.id.goto_first);
        button.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                mPager.setCurrentItem(0);
            }
        });
        button = (Button)findViewById(R.id.goto_last);
        button.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                mPager.setCurrentItem(NUM_ITEMS-1);
            }
        });
    }

    public static class MyAdapter extends FragmentStatePagerAdapter {
        public MyAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public int getCount() {
            return NUM_ITEMS;
        }

        @Override
        public Fragment getItem(int position) {
            return ArrayListFragment.newInstance(position);
        }
    }

    public static class ArrayListFragment extends ListFragment {
        int mNum;

        /**
         * Create a new instance of CountingFragment, providing "num"
         * as an argument.
         */
        static ArrayListFragment newInstance(int num) {
            ArrayListFragment f = new ArrayListFragment();

            // Supply num input as an argument.
            Bundle args = new Bundle();
            args.putInt("num", num);
            f.setArguments(args);

            return f;
        }

        /**
         * When creating, retrieve this instance's number from its arguments.
         */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            mNum = getArguments() != null ? getArguments().getInt("num") : 1;
        }

        /**
         * The Fragment's UI is just a simple text view showing its
         * instance number.
         */
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View v = inflater.inflate(R.layout.fragment_pager_list, container, false);
            View tv = v.findViewById(R.id.text);
            ((TextView)tv).setText("Fragment #" + mNum);
            return v;
        }

        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);
            setListAdapter(new ArrayAdapter<String>(getActivity(),
                    android.R.layout.simple_list_item_1, Cheeses.sCheeseStrings));
        }

        @Override
        public void onListItemClick(ListView l, View v, int position, long id) {
            Log.i("FragmentList", "Item clicked: " + id);
        }
    }
}

Answer 1

onCLickListener中的v引用Button本身,并且在按钮上调用findViewByID意味着该按钮正在查看其子项(它没有任何内容)来查找EditText元素.如果此代码在活动中运行,您可以执行以下操作:

Button bm = (Button) findViewById(R.id.bm);
bm.setOnClickListener(new OnClickListener() {
  public void onClick(View v) {
    EditText editTextIn1 = (EditText) findViewById(R.id.editTextIn1);
  }
});

或者,如果您有对片段容器的引用(如framelayout或其他东西),您可以这样做

Button bm = (Button) findViewById(R.id.bm);
bm.setOnClickListener(new OnClickListener() {
  public void onClick(View v) {
    EditText editTextIn1 = (EditText) myFragmentContainer.findViewById(R.id.editTextIn1);
  }
});