Question

我有一个应用程序，它从一段json文本中读取一些数据。我有两个班级。

现在两个类都显示已注册成员的完整列表。但我想要实现的是，当一个成员被点击时，我只能看到那个成员，而不是其他成员。

以下是两个类的代码：

从列表视图中：

public class Listviewer extends ListActivity {

 @Override
 public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);


    setContentView(R.layout.listplaceholder);


    ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();


    JSONObject json = JSONfunctions.getJSONfromURL("http://de-saksen.nl/deelnemers.txt");

    try{

        JSONArray  deelnemers = json.getJSONArray("deelnemers");

        for(int i=0;i<deelnemers.length();i++){                     
            HashMap<String, String> map = new HashMap<String, String>();    
            JSONObject e = deelnemers.getJSONObject(i);

            map.put("id",  String.valueOf(i));
            map.put("name", "Character Naam: " +  e.getString("naamingw2"));
            map.put("sex", "Geslacht: " +  e.getString("geslacht"));
            map.put("rank", "Rang: " +  e.getString("rang"));

            mylist.add(map);            
        }   



    }catch(JSONException e)        {
         Log.e("log_tag", "Error parsing data "+e.toString());
    }

    ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.main, 
                    new String[] { "name", "sex", "rank"}, 
                    new int[] { R.id.item_title, R.id.item_subtitle, R.id.item_subtitle2 });

    setListAdapter(adapter);

    final ListView lv = getListView();
    lv.setTextFilterEnabled(true);  
    lv.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {              
            Intent intent = new Intent(Listviewer.this, Profileviewer.class);   
            startActivity(intent); 
        }
    });



}

}

从个人资料视图中：

public class Profileviewer extends ListActivity {


 @Override
 public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);


    setContentView(R.layout.listplaceholder);


    ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();


    JSONObject json = JSONfunctions.getJSONfromURL("http://de-saksen.nl/deelnemers.txt");

    try{

        JSONArray  deelnemers = json.getJSONArray("deelnemers");

        for(int i=0;i<deelnemers.length();i++){                     
            HashMap<String, String> map = new HashMap<String, String>();    
            JSONObject e = deelnemers.getJSONObject(i);

            map.put("id",  String.valueOf(i));
            map.put("name", "Naam: " +  e.getString("naamingw2"));
            map.put("sex", "Geslacht: " +  e.getString("geslacht"));
            map.put("rank", "Rang: " +  e.getString("rang"));
            map.put("race", "Ras: " +  e.getString("ras"));
            map.put("profession", "Beroep: " +  e.getString("beroep"));
            map.put("skills", "Hobby's: " +  e.getString("hobbys"));
            map.put("lvl", "Level: " +  e.getString("level"));
            mylist.add(map);            
        }   



    }catch(JSONException e)        {
         Log.e("log_tag", "Error parsing data "+e.toString());
    }

    ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.profile, 
                    new String[] { "name", "sex", "rank", "race", "profession", "skills", "lvl" }, 
                    new int[] { R.id.item_title, R.id.item_subtitle, R.id.item_subtitle2, R.id.item_subtitle3, R.id.item_subtitle4, R.id.item_subtitle5, R.id.item_subtitle6 });

    setListAdapter(adapter);

    final ListView lv = getListView();
    lv.setTextFilterEnabled(true);  
    lv.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {              
            Intent intent = new Intent(Profileviewer.this, Listviewer.class);   
            startActivity(intent); 
        }
    });



}
}

我需要将一个变量传递给包含已点击成员的另一个类，但我该如何实现呢？

Answer 1

使用意图：

lv.setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {              
        Intent intent = new Intent(Profileviewer.this, Listviewer.class);
        intent.putExtra("Key", value);
        startActivity(intent); 
    }
});

然后在Listviewer.java中：

getIntent().getStringExtra("Key"); //for example

要传递用户数据，请修改如下：

String [] users = new String[] { "name", "sex", "rank", "race", "profession", "skills", "lvl" };
int[] ids = new int[] { R.id.item_title, R.id.item_subtitle, R.id.item_subtitle2, R.id.item_subtitle3, R.id.item_subtitle4, R.id.item_subtitle5, R.id.item_subtitle6 };

ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.profile, 
                users, ids);

setListAdapter(adapter);

final ListView lv = getListView();
lv.setTextFilterEnabled(true);  
lv.setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {              
        Intent intent = new Intent(Profileviewer.this, Listviewer.class);   
        intent.putExtra("Key", users[position]);
        startActivity(intent); 
    }
});

Answer 2

If you want to pass int value:

categoryView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                Toast.makeText(CategoryView.this, "id::" + id,
                        Toast.LENGTH_SHORT).show();

                Intent menuIntent = new Intent(CategoryView.this,MenuListView.class);
                Bundle b = new Bundle();
                b.putInt("categoryId", (int) id); //Your id
                menuIntent.putExtras(b);
                menuIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(menuIntent);
                //finish();

            }

        });

Answer 3

您可以在使用Extras创建Intent对象时发送基本信息。看看http://developer.android.com/guide/components/intents-filters.html。

如果您必须加载大量信息且额外信息不够，您只需发送一个“密钥”即可用于收回所需的所有信息。

例如：

ThisClass

Intent intent = new Intent(thisClass, otherClass);
intent.putExtra("id", "1");
intent.putExtra("model", "model1");
startActivity(inte);

OtherClass

String query = "SELECT * FROM " + T_NAME + " WHERE 'id' = " + getIntent().getIntExtra("id",0);
Cursor c = db.rawQuery(query, null)

将信息从一个意图传递到另一个意图

3 个答案: