Question

我创建了包含listview的3个片段。我在listivew上方添加了一个floatingActionButton，它显示在3个片段中。它假设floatingActionButton在click上打开一个链接。但它在word适配器中给出了一个错误（startActivity（intent）; ...

其中一个片段的代码：

  import android.content.Context;
  import android.media.AudioManager;
  import android.media.MediaPlayer;
  import android.os.Bundle;
  import android.support.v4.app.Fragment;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.AdapterView;
  import android.widget.ListView;
  import java.util.ArrayList;

  public class GreetingsFragment extends Fragment {

private MediaPlayer mMediaPlayer;
private AudioManager mAudioManager;

private AudioManager.OnAudioFocusChangeListener mOnAudioFocusChangeListener = new AudioManager.OnAudioFocusChangeListener() {
    @Override
    public void onAudioFocusChange(int focusChange) {
        if (focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT ||
                focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK) {

            mMediaPlayer.pause();
            mMediaPlayer.seekTo(0);
        } else if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
            mMediaPlayer.start();
        } else if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {

            releaseMediaPlayer();
        }
    }
};


private MediaPlayer.OnCompletionListener mCompletionListener = new MediaPlayer.OnCompletionListener() {
    @Override
    public void onCompletion(MediaPlayer mediaPlayer) {
        releaseMediaPlayer();
    }
};

public GreetingsFragment() {
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.word_list, container, false);

    mAudioManager = (AudioManager) getActivity().getSystemService(Context.AUDIO_SERVICE);

    // Create a list of words
    final ArrayList<Word> words = new ArrayList<Word>();

    words.add(new Word(R.string.test1, R.string.test2, R.drawable.test3,
            R.raw.test4));
    words.add(new Word(R.string.test1, R.string.test2, R.drawable.test3,
            R.raw.test4));
    words.add(new Word(R.string.test1, R.string.test2, R.drawable.test3,
            R.raw.test4));
    words.add(new Word(R.string.test1, R.string.test2, R.drawable.test3,
            R.raw.test4));

    WordAdapter adapter = new WordAdapter(getActivity(), words, R.color.category_greetings);
    ListView listView = (ListView) rootView.findViewById(R.id.list);
    listView.setAdapter(adapter);

    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
            releaseMediaPlayer();
            Word word = words.get(position);
            int result = mAudioManager.requestAudioFocus(mOnAudioFocusChangeListener,
                    AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);
            if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {

                mMediaPlayer = MediaPlayer.create(getActivity(), word.getAudioResourceId());
                mMediaPlayer.start();
                mMediaPlayer.setOnCompletionListener(mCompletionListener);
            }
        }
    });

    return rootView;       
}
@Override
public void onStop() {
    super.onStop();

    releaseMediaPlayer();
}

private void releaseMediaPlayer() {
    if (mMediaPlayer != null) {
        mMediaPlayer.release();
        mMediaPlayer = null;
        mAudioManager.abandonAudioFocus(mOnAudioFocusChangeListener);
    }
}

}

wordAdapter的代码

`import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.support.design.widget.FloatingActionButton;
 import android.support.v4.content.ContextCompat;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
 import android.widget.ImageView;
 import android.widget.TextView;
 import java.util.ArrayList;

  public class WordAdapter extends ArrayAdapter<Word>  {
private int mColorResourceId;


public WordAdapter(Context context, ArrayList<Word> words, int colorResourceId) {
    super(context, 0, words);
    mColorResourceId = colorResourceId;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View listItemView = convertView;
    if (listItemView == null) {
        listItemView = LayoutInflater.from(getContext()).inflate(
                R.layout.list_item, parent, false);
    }



    Word currentWord = getItem(position);

    TextView SaudiTextView = (TextView) listItemView.findViewById(R.id.s_text_view);

    SaudiTextView.setText(currentWord.getsTranslationId());

    TextView defaultTextView = (TextView) listItemView.findViewById(R.id.default_text_view);

    defaultTextView.setText(currentWord.getDefaultTranslationId());

    FloatingActionButton fab = (FloatingActionButton) listItemView.findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Uri uri = Uri.parse("https://www.facebook.com"); 
            Intent intent = new Intent(Intent.ACTION_VIEW, uri);
            startActivity(intent);
        }
    });

    ImageView imageView = (ImageView) listItemView.findViewById(R.id.image);

    if (currentWord.hasImage()) {
        imageView.setImageResource(currentWord.getImageResourceId());
        imageView.setVisibility(View.VISIBLE);
    } else {
        imageView.setVisibility(View.GONE);
    }

    View textContainer = listItemView.findViewById(R.id.text_container);

    int color = ContextCompat.getColor(getContext(), mColorResourceId);
    textContainer.setBackgroundColor(color);

    return listItemView;

}

}`

Answer 1

使用startActivity（intent）

应用上下文

context.startActivity(intent);

上面的代码将在您的最后工作。

适配器需要一个上下文才能调用startActivity()方法。

根据您的需要，使用适配器类替换以下代码：

import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.support.design.widget.FloatingActionButton;
 import android.support.v4.content.ContextCompat;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
 import android.widget.ImageView;
 import android.widget.TextView;
 import java.util.ArrayList;

  public class WordAdapter extends ArrayAdapter<Word>  {
private int mColorResourceId;
private Context context;


public WordAdapter(Context context, ArrayList<Word> words, int colorResourceId) {
    super(context, 0, words);
    mColorResourceId = colorResourceId;
    this.context = context;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View listItemView = convertView;
    if (listItemView == null) {
        listItemView = LayoutInflater.from(getContext()).inflate(
                R.layout.list_item, parent, false);
    }



    Word currentWord = getItem(position);

    TextView SaudiTextView = (TextView) listItemView.findViewById(R.id.s_text_view);

    SaudiTextView.setText(currentWord.getsTranslationId());

    TextView defaultTextView = (TextView) listItemView.findViewById(R.id.default_text_view);

    defaultTextView.setText(currentWord.getDefaultTranslationId());

    FloatingActionButton fab = (FloatingActionButton) listItemView.findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Uri uri = Uri.parse("https://www.facebook.com"); 
            Intent intent = new Intent(Intent.ACTION_VIEW, uri);
            context.startActivity(intent);
        }
    });

    ImageView imageView = (ImageView) listItemView.findViewById(R.id.image);

    if (currentWord.hasImage()) {
        imageView.setImageResource(currentWord.getImageResourceId());
        imageView.setVisibility(View.VISIBLE);
    } else {
        imageView.setVisibility(View.GONE);
    }

    View textContainer = listItemView.findViewById(R.id.text_container);

    int color = ContextCompat.getColor(getContext(), mColorResourceId);
    textContainer.setBackgroundColor(color);

    return listItemView;

}
}

Answer 2

只需更改

//Creates Div
var d = document.createElement("div");
document.body.appendChild(d);

//Creates iFrame
var n = document.createElement("iframe");
n.id = "microcom-frame";
n.style.width = "100%";
n.style.height = "100%";
n.style.background = "transparent";
n.style.position = "relative";
n.style.margin = 0;
n.style.border = "none";
n.style.overflow ="hidden";
n.style.display = "block";

//Append iFrame inside Div
d.appendChild(n);

//Write content to iFrame
n.srcdoc = "<!doctype html><html><head></head><body><div id='root'>Example content</div></body></html>";

到

startActivity(intent);

在这种情况下，您需要应用程序的上下文，并将context.startActivity(intent);作为上下文传递给适配器。

在listview上面的floatingActionButton

2 个答案: