两次与空值开幕活动 [英] Twice opening activity with an null value

问题描述

我有，当你在任何按钮，点击其中先用意图值发送到包含列表视图填充数据库的另一个活动一些按钮的活动。我想用这个值作为其中command选择填充列表视图的特殊内容

i have an activity with some buttons in which when you click on any of buttons First with Intent send a value to another activity that contains a list view is filled with database. And I want to use this value as a parameter for where command select for filling list view with special Content

现在我有一个问题，就是当运行程序，当点击一个按钮，首先打开一个空列表视图，然后单击后退按钮后，列表视图正确显示数据。

now i have a problem that when run program and when click on a button, first open a empty list view and after clicking back-button, list view is correctly displayed data.

哪里是我的错？

源MainActivity

source MainActivity

最终意图I =新意图（MainActivity.this，ListActivity.class）;

final Intent i = new Intent(MainActivity.this,ListActivity.class);

    btn_irani.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            i.putExtra("position","ایران");
            startActivity(i);

            startActivity(GoToList);

        }
    });


    btn_turkie.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
              i.putExtra("position","ترکیه");
                startActivity(i);
            startActivity(GoToList);

        }
    });

源ListActivity

source ListActivity

public class ListActivity extends Activity {





    String value = "";
    MovieDB myDbHelper;
    SQLiteDatabase db;
    ListAdapter adapter;
    ArrayList<HashMap<String, String>> data;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.list_layout);






        value = getIntent().getStringExtra("position");


        ListView lst=(ListView) findViewById(R.id.listView1);
        Load_Database();
        db = myDbHelper.getReadableDatabase();



        Cursor  c = db.rawQuery("select * from movie_list where product = '"+value+"'", null);

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

            for (; c.moveToNext();) {
                HashMap<String, String> map = new HashMap<String, String>();
                String img = c.getString(c.getColumnIndex("img"));
                String name = c.getString(c.getColumnIndex("name"));
                map.put("img", img);
                map.put("name", name);
                data.add(map);
            }
            adapter = new ListMovie(this, data);

            lst.setAdapter(adapter);

    }

请帮帮我！

推荐答案

我想你已经叫 startActivity（）两次错误。如果你想要一个值发送到你的下一个活动，同时称这是一次 startActivity（）就足够了。

I think you have called startActivity() twice by mistake. If you want to send a value to your next Activity while calling it once startActivity() is sufficient.

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