我能够在第一个Activity中将ListView中的字符串成功转移到第二个Activity中的EditText。我现在想要编辑文本并将其发回以在我的第一个活动中更新我的ListView。我基本上希望将编辑作为弹出窗口发送回第一个活动，以帮助我测试哪个字符串被传回
我不确定在onActivityResult()中放置什么意图：
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK && requestCode == REQUEST_CODE) {
String name = data.getExtras().getString("name");
Toast.makeText(this, name, Toast.LENGTH_SHORT).show();
}
}
这是我的第一个活动：
public class ToDoActivity extends Activity {
private ArrayList<String> todoItems;
private ArrayAdapter<String> todoAdapter; // declare array adapter which will translate the piece of data to teh view
private ListView lvItems; // attach to list view
private EditText etNewItem;
private final int REQUEST_CODE = 20;
//private Intent i;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_to_do);
etNewItem = (EditText) findViewById(R.id.etNewItem);
lvItems = (ListView) findViewById(R.id.lvItems); // now we have access to ListView
//populateArrayItems(); // call function
readItems(); // read items from file
todoAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, todoItems); //create adapter
lvItems.setAdapter(todoAdapter); // populate listview using the adapter
//todoAdapter.add("item 4");
setupListViewListener();
setupEditItemListener();
onActivityResult(REQUEST_CODE, RESULT_OK, /** Intent variable **/);
}
private void launchEditItem(String item) {
Intent i = new Intent(this, EditItemActivity.class);
i.putExtra("itemOnList", item); // list item into edit text
//startActivityForResult(i, REQUEST_CODE);
startActivity(i);
}
private void setupEditItemListener() { // on click, run this function to display edit page
lvItems.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> adapter, View item, int pos, long id) {
String text = (String) lvItems.getItemAtPosition(pos);
launchEditItem(text);
}
});
}
private void setupListViewListener() {
lvItems.setOnItemLongClickListener(new OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> adapter, View item, int pos, long id) {
todoItems.remove(pos);
todoAdapter.notifyDataSetChanged(); // has adapter look back at the array list and refresh it's data and repopulate the view
writeItems();
return true;
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.to_do, menu);
return true;
}
public void onAddedItem(View v) {
String itemText = etNewItem.getText().toString();
todoAdapter.add(itemText); // add to adapter
etNewItem.setText(""); //clear edit text
writeItems(); //each time to add item, you want to write to file to memorize
}
private void readItems() {
File filesDir = getFilesDir(); //return path where files can be created for android
File todoFile = new File(filesDir, "todo.txt");
try {
todoItems = new ArrayList<String>(FileUtils.readLines(todoFile)); //populate with read
}catch (IOException e) { // if files doesn't exist
todoItems = new ArrayList<String>();
}
}
private void writeItems() {
File filesDir = getFilesDir(); //return path where files can be created for android
File todoFile = new File(filesDir, "todo.txt");
try {
FileUtils.writeLines(todoFile, todoItems); // pass todoItems to todoFile
} catch (IOException e) {
e.printStackTrace();
}
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK && requestCode == REQUEST_CODE) {
String name = data.getExtras().getString("name");
Toast.makeText(this, name, Toast.LENGTH_SHORT).show();
}
}
}
我考虑过使用第二项活动中的Intent，但我不知道该怎么做。
这是我的第二个活动。
public class EditItemActivity extends Activity {
private EditText etEditItem;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_edit_item);
Intent i = getIntent();
String ItemToEdit = i.getStringExtra("itemOnList");
etEditItem = (EditText)findViewById(R.id.etEditItem);
etEditItem.setText(ItemToEdit);
onSubmit(etEditItem);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.edit_item, menu);
return true;
}
public void DoneEdit(View v) {
this.finish();
}
public void onSubmit(View v) {
EditText etName = (EditText) findViewById(R.id.etEditItem);
Intent data = new Intent();
data.putExtra("EditedItem", etName.getText().toString());
setResult(RESULT_OK, data);
finish();
}
}
答案 0 :(得分：3)
要从活动（孩子）获得结果，请执行以下操作：
在父活动中
startActivityForResult(myIntent, 1);
您父项活动的全球变量
boolean backFromChild = false;
String aString;
然后仍在父活动中
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) {
if (resultCode == RESULT_OK) {
// code for result
aString = getIntent().getExtras().getString("aString");
backFromChild = true;
}
if (resultCode == RESULT_CANCELED) {
// Write your code on no result return
}
}
}
在你的孩子中，你会做某事
Intent returnIntent = new Intent();
//example of sending back a string to the parent.
returnIntent.putExtra("aString", aString);
setResult(RESULT_OK, returnIntent);
finish();
事情是，从您的孩子返回时，您的父活动的onResume将被调用。在那里你必须执行更新，在你的情况下，它是更新编辑文本的信息：
@Override
public void onResume(){
super.onResume();
if (backFromChild){
backFromChild = false;
//do something with aString here
Toast.makeText(this, aString, Toast.LENGTH_SHORT).show();
}
}
基本上，在onActivityResult我从孩子的意图中获取信息。然后在onResume我使用此信息。
答案 1 :(得分：1)
如果您担心，可以使用SharedPreferences
例如：将数据放入SP中的第二个活动
SharedPreferences spppp = getSharedPreferences("tab", 0);
SharedPreferences.Editor editors = spppp.edit();
editors.putString("for", "0");
editors.commit();
并在第一个活动中获取列表视图的数据，如此
SharedPreferences spppp = getSharedPreferences("tab", 0);
String your_list_view_value = spppp.getString("for", "");