Question

我正在尝试将字符串发送到我的列表视图。遗憾的是，数据未被发送并且没有显示任何错误。主活动具有列表视图，用户单击按钮（将它们带到第二个活动），在那里他们可以输入产品名称，并且应该自动将它们带回主活动。

这确实有效，但我必须搞砸了。我错过了什么吗？

MainActivity.java

  public class MainActivity extends Activity {
        private ListView listView;
        private String[] details;
        public static ArrayList<String> names = new ArrayList<>();
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            listView = (ListView) findViewById(R.id.listView);
    // replace \ with left angle bracket in the line below
            ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, names);
            listView.setAdapter(arrayAdapter);
            listView.setOnItemClickListener(

                    new AdapterView.OnItemClickListener() {
                        @Override
                        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                        }
                    }
                );
            }

    }

第二项活动

public class Main2Activity extends Activity {
    private EditText textName;
    private EditText textModel;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        textName=(EditText)findViewById(R.id.inputName);
        textModel=(EditText)findViewById(R.id.inpuModelNumber);



    }
    public void addNames(View v){
        MainActivity.names.add(textName.getText().toString());

        finish();
    }


}

Answer 1

据我所知，你想把字符串的数组列表传递给另一个活动

在您的活动中创建arraylist

public class Main2Activity extends Activity {
    private EditText textName;
    private EditText textModel;
    ArrayList<String> names = new ArrayList<>();
    @Override 
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        textName=(EditText)findViewById(R.id.inputName);
        textModel=(EditText)findViewById(R.id.inpuModelNumber);

    } 
    public void addNames(View v){
       names.add(textName.getText().toString());

       Intent intent = new Intent(Main2Activity .this, MainActivity .class);
       intent.putStringArrayListExtra("keyNames", names);
       startActivity(intent);
       finish();

    } 
}

然后解析传递的字符串数组

在oncreate中

 Intent i = getIntent();  
    ArrayList<String> list = i.getStringArrayListExtra("keyNames");

我希望这可以帮到你

Answer 2

listView.setAdapter(arrayAdapter);
            listView.setOnItemClickListener(

                    new AdapterView.OnItemClickListener() {
                        @Override
                        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

Intent newPage = new Intent(getActivity().getApplicationContext(),
        Main2Activity.class);
newPage.putExtra("TITLE", title);
newPage.putExtra("DATE", date);
newPage.putExtra("CONTENT", content);
startActivity(newPage);


                        }
                    }
                );
            }

然后在Main2Activity的onCreate（）方法中：

Bundle extras = getIntent().getExtras();
if(extras !=null) {
    String title = extras.getString("TITLE");
    String date = extras.getString("DATE");
    String content = extras.getString("CONTENT");
}

字符串数据不会被发送到主要活动

2 个答案: