我正在开发一个应用程序（字典）
使用Volley从JSON格式的链接获取单词，发音，定义，图像名称
然后解析JSON并在屏幕顶部显示单词列表和EditText以搜索单词。一切都好。但我不知道如何处理点击事件，如何将所选项目的数据传递给另一个活动并在那里接收
因此，当选择列表项时，DetailsActivity应显示Word，发音，定义和设置图像名称（如果有）。
我从网络服务中收到的 JSON
{
"words": [
{
"id": "1",
"the_word": "first word",
"pronunciation": "pronun",
"definition": "def",
"image_name": "img_01"
},
{
"id": "2",
"the_word": "second word",
"pronunciation": "pronun2",
"definition": "def2",
"image_name": "img_02"
},
{
"id": "3",
"the_word": "third word",
"pronunciation": "pronun3",
"definition": "def3",
"image_name": "img_03"
}
]
}
Word.java 类作为模型
public class Word {
private String the_word;
private String pronunciation;
private String definition;
private String image_name;
public String getThe_word() {
return the_word;
}
public void setThe_word(String the_word) {
this.the_word = the_word;
}
public String getPronunciation() {
return pronunciation;
}
public void setPronunciation(String pronunciation) {
this.pronunciation = pronunciation;
}
public String getDefinition() {
return definition;
}
public void setDefinition(String definition) {
this.definition = definition;
}
public String getImage_name() {
return image_name;
}
public void setImage_name(String image_name) {
this.image_name = image_name;
}
}
WordAdapter.java 类作为适配器（稍后我将处理图像）
public class WordAdapter extends BaseAdapter {
Context context;
LayoutInflater inflater;
List<Word> data;
public WordAdapter(Context context, List<Word> data) {
this.context = context;
this.data = data;
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
TextView word;
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View itemView = inflater.inflate(R.layout.word_item, parent, false);
word = (TextView) itemView.findViewById(R.id.t_word);
word.setText(data.get(position).getThe_word());
return itemView;
}
}
这是列表活动类
public class WordsList extends AppCompatActivity {
private static final String url = "http://mywebaddress.com/dictionary/showWords.php";
ListView listView;
WordAdapter adapter;
ProgressDialog PD;
List<Word> arrayListOfWords;
EditText editText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_words_list);
listView = (ListView) findViewById(R.id.list);
editText = (EditText) findViewById(R.id.search);
PD = new ProgressDialog(this);
PD.setMessage("Loading ...");
PD.show();
getListView().setOnItemClickListener(new ListItemClickListener());
ReadDataFromDB();
editText.addTextChangedListener(filterTextWatcher);
}
private void ReadDataFromDB() {
PD.show();
JsonObjectRequest jsonObject = new JsonObjectRequest(Method.POST, url,new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
arrayListOfWords = new ArrayList<>();
try {
JSONArray ja = response.getJSONArray("words");
for (int i = 0; i < ja.length(); i++) {
JSONObject jsonWordsList = ja.getJSONObject(i);
Word word = new Word();
word.setThe_word(jsonWordsList.optString("the_word"));
word.setPronunciation(jsonWordsList.optString("pronunciation"));
word.setDefinition(jsonWordsList.optString("definition"));
word.setImage_name(jsonWordsList.optString("image_name"));
arrayListOfWords.add(word);
PD.dismiss();
}
} catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "inside JSONException", Toast.LENGTH_LONG).show();
}
adapter = new WordAdapter(WordsList.this, arrayListOfWords);
editText.addTextChangedListener(filterTextWatcher);
listView.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
PD.dismiss();
}
});
AppController.getInstance().addToRequestQueue(jsonObject);
}
private TextWatcher filterTextWatcher = new TextWatcher() {
public void afterTextChanged(Editable s) {
}
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
List<Word> foundItems = new ArrayList<>();
if (arrayListOfWords != null) {
getWordsList(s, foundItems);
listView.setAdapter(new WordAdapter(getApplicationContext(), foundItems));
adapter.notifyDataSetChanged();
}
}
};
public void getWordsList(CharSequence s, List<Word> list) {
for (Word word : arrayListOfWords) {
if (word.getThe_word().contains(s)) {
list.add(word);
}
}
}
public ListView getListView() {
return listView;
}
class ListItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent i = new Intent(WordsList.this,DetailsActivity.class);
i.putExtra("selected_word", (Parcelable) arrayListOfWords.get(position));
startActivity(i);
}
}
}
正如我所说的一切正常但是在列表项上点击！
实际上这段代码就是问题：
class ListItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent i = new Intent(WordsList.this,DetailsActivity.class);
i.putExtra("selected_word", (Parcelable) arrayListOfWords.get(position));
startActivity(i);
}
}
如何将列表中所选项目的the_word，发音，定义和image_name传递给 DetailsActivity.java 以及如何将它们传递到那里？
谢谢！
修改
所以我找到了一种非常简单的方法来传递我一直使用的数据!!!
但是我不确定这是不是最好的做法而且我确信有更好的方法。考虑到你将要传递更多数据的时间，然后我的解决方案将令人沮丧
这就是我在做的事：
使用putExtra发送...
class ListItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String passingWord = String.valueOf(arrayListOfWords.get(position).getThe_word());
String passingPr = String.valueOf(arrayListOfWords.get(position).getPronunciation());
String passingDf = String.valueOf(arrayListOfWords.get(position).getDefinition());
String passingIm = String.valueOf(arrayListOfWords.get(position).getImage_name());
Intent i = new Intent(WordsList.this,DetailsActivity.class);
i.putExtra("selected_word", passingWord);
i.putExtra("selected_pr", passingPr);
i.putExtra("selected_df", passingDf);
i.putExtra("selected_im", passingIm);
startActivity(i);
}
}
并在 DetailsActivity.java 获取StringExtra：
Intent intent = getIntent();
String the_word = intent.getStringExtra("selected_word");
String pronunciation = intent.getStringExtra("selected_pr");
String definition = intent.getStringExtra("selected_df");
String image_name = intent.getStringExtra("selected_im");
的修改
上述代码没有问题，直到您搜索单词而不是单击列表项，DetailsActivity会显示不同的选定单词详细信息。
实际上，当您搜索单词时，列表中可能会有两个或三个项目通过过滤字母显示。如果选择第一个，在DetailsActivity中，您将看到整个词典列表中第一个单词的详细信息。这意味着所选位置是错误的
所以我改变了我的代码并重新编写它，这次它按照我的预期工作。我会分享它作为这个问题的答案，对谁来说可能有这样的麻烦。
答案 0 :(得分：0)
我认为在活动之间实现发送复合对象的最佳方法是EventBus。您只需创建一个要传递的新对象（可以是任何类型，例如您的自定义类）并使用：
MyClass myObject = new MyClass; // initialize the object how you like
//and post it
eventBus.post(myObject);
然后在＆＃39;接收器＆＃39;活动，创建一个@Subscribe方法，该方法将监听正在接收的此类对象：
@Subscribe
public void onMyClassEvent(MyClass myObject){
//your logic here
}
让 EventBus 工作并不难，他们有很棒的指南，但如果你遇到任何麻烦，请写下来。
答案 1 :(得分：0)
尝试以下代码获取意图数据：
String the_word = getIntent().getExtras().getString("selected_word");
String pronunciation = getIntent().getExtras().getString("selected_pr");
String definition = getIntent().getExtras().getString("selected_df");
String image_name = getIntent().getExtras().getString("selected_im");