[英]Populating listview on main activity from another activity
I managed to pass string to main activity from another by intent and showing it as textView. 我设法通过意图将字符串从另一个传递给主要活动,并将其显示为textView。 Is there a similar logic to populate the listview on main? 是否有类似的逻辑可填充main上的listview?
private Button startQr;
private ListView validList;
private ArrayList<String> strArray;
private ArrayAdapter<String> adapter;
// private TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_caffe_list);
validList = (ListView)findViewById(R.id.listView);
startQr = (Button)findViewById(R.id.scanButton);
strArray = new ArrayList<>();
adapter = new ArrayAdapter<String>(getApplicationContext(),android.
R.layout.simple_expandable_list_item_1, strArray);
validList.setAdapter(adapter);
startQr.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(First.this, Second.class);
startActivity(i);
}
});
Intent intent = getIntent();
String message = intent.getStringExtra(SecondActivity.EXTRA_MESSAGE);
//textView = (TextView)findViewById(R.id.textView1);
//textView.setText(message);
The second class: 第二类:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.second_activity);
btn = (Button)findViewById(R.id.button);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
getCode();
finish();
}
});
}
public void getCode() {
Intent intent = new Intent( Secondclass.this, First.class);
EditText editText = (EditText) findViewById(R.id.editText);
String array = editText.getText().toString();
intent.putExtra(EXTRA_ARRAY, array);
startActivity(intent);
}
It worked for a single editText. 它适用于单个editText。
If you want to populate the ListView
from main, you should send an Intent
如果要从main填充ListView
,则应发送一个Intent
But this time you need to send as extra the ArrayList<String>
. 但是这一次,您需要额外发送ArrayList<String>
。
So you need to implement the following code to send the Intent: 因此,您需要实现以下代码来发送Intent:
static final String EXTRA_ARRAY = "com.package.app.STRARRAY";
private ArrayList<String> strArray = new ArrayList<>();
Intent intent = new Intent(getActivity(), Second.class);
intent.putExtra(EXTRA_ARRAY, strArray);
startActivity(intent);
And in order to receive the intent you need to implement the following code: 并且为了接收意图,您需要实现以下代码:
static final String EXTRA_ARRAY = "com.package.app.STRARRAY";
Intent intent = getIntent();
ArrayList<String> strArray = intent.getStringArrayListExtra(EXTRA_ARRAY);
Instead of calling startActivity(i);
而不是调用startActivity(i);
from your first Activity
call startActivityForResult(i,REQUEST_CODE);
从您的第一个Activity
调用startActivityForResult(i,REQUEST_CODE);
. 。 This will help you listen to whatever the Second Activity
has to say/return as a result. 这将帮助您聆听Second Activity
的结果。
The result will be received in the form of an Intent
. 结果将以Intent
的形式接收。 You need to @Override
onActivityResult()
in your First Activity
. 您需要在First Activity
@Override
onActivityResult()
。
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// Check which request we're responding to
if (requestCode == REQUEST_CODE) {
// Make sure the request was successful
if (resultCode == RESULT_OK) {
// The user picked a contact.
// The Intent's data Uri identifies which contact was selected.
// Do something with the contact here (bigger example below)
}
}
}
Check out Android Documentation to know more about how to get result. 查看Android文档,以了解有关如何获得结果的更多信息。
Now to set the Result, In the Second Activity you need to call setResult()
. 现在设置结果,在第二个活动中,您需要调用setResult()
。
Bundle data = new Bundle();
data.putString("data", "here goes you data");
Intent intent = new Intent();
intent.putExtras(data);
setResult(RESULT_OK, intent);
finish();
calling finish()
after setResult()
send the data to the Activity
from where it was called. 在setResult()
finish()
之后,调用finish()
将数据从调用位置发送到Activity
。
Hope it helps! 希望能帮助到你!
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