我从我的Api获取我的Json对象/数组并将其打印到我的视图中， foreach数组我在我的MainActivity中打印id名称。
Foreach数组数据我创建了一个按钮。 我想转移到另一个Activity并显示当前数组的相关数据。
我的观点看起来像这样：
________________________
id name button <- if one clicks on the button another activity shall show the description of it
________________________
我的主要问题是如何在另一项活动中显示相关数据。
我的MainActivity看起来像这样：
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
private final static String TAG = MainActivity.class.getSimpleName();
private ProgressDialog pDialog;
private ListView lv;
// URL to get contacts JSON
private static String url = "http://192.168.178.58:8888/test";
ArrayList<HashMap<String, String>> contactList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
contactList = new ArrayList<>();
new GetContacts().execute();
lv = (ListView) findViewById(R.id.list);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
}
/**
* Async task class to get json by making HTTP call
*/
private class GetContacts extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
HttpHandler sh = new HttpHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url);
if (jsonStr != null) {
try {
// Getting JSON Array node
JSONArray jsonArray = new JSONArray(jsonStr);
// looping through All Contacts
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject c = jsonArray.getJSONObject(i);
String id = c.getString("id");
String name = c.getString("name");
String description = c.getString("description");
// tmp hash map for single contact
HashMap<String, String> data = new HashMap<>();
// adding each child node to HashMap key => value
data.put("id", id);
data.put("name", name);
data.put("description", description);
// adding contact to contact list
contactList.add(data);
}
} catch (final JSONException e) {
Log.e(TAG, "Json parsing error: " + e.getMessage());
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Json parsing error: " + e.getMessage(),
Toast.LENGTH_LONG)
.show();
}
});
}
} else {
Log.e(TAG, "Couldn't get json from server.");
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Couldn't get json from server. Check LogCat for possible errors!",
Toast.LENGTH_LONG)
.show();
}
});
}
return null;
}
/**
* In onPostExecute() method the progress dialog is dismissed and the array list data is displayed in list view using an adapter.
* @param result
*/
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
*/
ListAdapter adapter = new SimpleAdapter(
MainActivity.this, contactList,
R.layout.list_item,
new String[]{"name", "description"},
new int[]{R.id.name, R.id.description});
lv.setAdapter(adapter);
}
}
}
编辑：
这就是我的意图：
public void openDetails() { // button onclick name
Intent myIntent = new Intent(MainActivity.this, DetailActivity.class);
myIntent.putExtra("key", value);
MainActivity.this.startActivity(myIntent);
}
答案 0 :(得分：1)
通常，您可以使用单例在活动之间共享非原始数据。
这样的事，
master然后在第一个活动中：
public class MyData {
private Object data;
public Object getData() {
return data;
}
public void setData(Object data) {
this.data = data;
}
private static final MyData myData = new MyData();
public static MyData getInstance() {
return myData;
}
}
在第二个：
MyData.getInstance().setData(objToShare);
答案 1 :(得分：0)
您当前的实施并不知道点击了哪个按钮。所有按钮都将具有相同的点击事件。
解决方案 - 不要在ListView上放置按钮。只需点击＆＃34;行＆＃34;即可。
要开始此操作，您需要替换HashMap<String, String>的列表，以支持自定义POJO类。
请参阅 - Parcelable objects
public class Contact implements Parcelable {
private String id, name, description;
// TODO: Getters & setters
// TODO: Actually implement Parcelable
}
然后，更新适配器。而不是SimpleAdapter。
请参阅 - Custom Adapter
private ContactAdapter adapter; // Top of class
...
// onCreate
contactList = new ArrayList<Contact>();
lv = (ListView) findViewById(R.id.list);
adapter = new ContactAdapter(MainActivity.this, contactList);
lv.setAdapter(adapter); // Set this here, not in the AsyncTask
...
// doInBackground
contactList.add(someContact);
// adapter.add(someContact); // Can also do this
// onPostExecute
adapter.notifyDataSetChanged(); // Refresh the adapter, don't lv.setAdapter again.
你的AsyncTask
// tmp object for single contact
Contact c = new Contact();
// adding each child node to object
c.setID(id);
c.setName(name);
c.setDescription(description);
// adding contact to contact list
contactList.add(c);
Gson会有所帮助。 改造可以取代你的整个AsyncTask，但我会留给你研究。
现在，回到＆＃34;点击事件＆＃34;。
由于此Contact对象为Parcelable，因此您可以将其传递给Intent，就像其他任何内容一样。
// onCreate
lv = (ListView) findViewById(R.id.list);
// This is a click per-row
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
Contact clicked = adapter.getItem(position);
displayContact(clicked);
}
});
我喜欢定义单独的方法来使代码更清晰。
private void displayContact(Contact c) {
Intent intent = new Intent();
intent.putExtra("contact", c); // The piece you're looking for
startActivity(intent);
}
从另一项活动中获取意图：
Contact c = getIntent().getExtras().getParcelable("contact");
参考 - Android: How to pass Parcelable object to intent and use getParcelable method of bundle?