问题：我想使用其他活动中的按钮从列表视图中删除项目。
我尝试了几种代码，但它似乎没有用。 我知道我使用serializable将对象捆绑到另一个活动。 但我不知道如何从其他活动中删除它。
有人可以帮我吗？ 我可以使用第二个活动中的按钮，在第一个活动中从列表视图中删除项目吗？
我得到ListView的A类
public class ListActivity extends Activity {
ListView list;
Button exit;
SimpleAdapter adapter;
final List<Map<String, String>> data = new ArrayList<Map<String, String>>();
@Override``
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
list = (ListView) findViewById(R.id.list);
exit = (Button) findViewById(R.id.btnExit);
// Registration numbers
final String[] title = new String[] { "XMT 123", "KLE 456", "CKL 789",
"MRP 012", "DSV 345" };
// Name of the truck drivers
final String[] subtitle = new String[] { "Peter Lund", "Hans Larsson",
"Erik Petersson", "Bjørn Lundal", "Lars Svensson" };
for (int i = 0; i < title.length; i++) {
Map<String, String> datalist = new HashMap<String, String>();
datalist.put("title", title[i]);
datalist.put("subtitle", subtitle[i]);
data.add(datalist);
}
// getDataInList();
adapter = new SimpleAdapter(this, data,
android.R.layout.simple_list_item_2, new String[] { "title",
"subtitle" }, new int[] { android.R.id.text1,
android.R.id.text2 });
list.setAdapter(adapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3) {
Intent intent = new Intent(ListActivity.this,
InformationActivity.class);
intent.putExtra("updateReg", title[position].toString());
intent.putExtra("updateName", subtitle[position].toString());
}
});
exit.setOnClickListener(new OnClickListener() {
// Closes the application
@Override
public void onClick(View v) {
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
});
}
B级，我拿到了接受按钮。 单击“接受”时，应删除A类列表视图中的项目。
public class InformationActivity extends Activity {
TextView name;
TextView reg;
TextView product;
TextView productNo;
Button accept;
Button edit;
Button exit;
AlertDialog dialog;
ListView list;
String result;
EditText search;
int requestCode = 1;
SimpleAdapter adapter;
Context context = InformationActivity.this;
ArrayList<Materials> materialList = new ArrayList<Materials>();
// Materials
final static String[] material = new String[] { "Betong", "Grus", "Järn",
"Metall", "Grus fin", "Grus grov", "Sten" };
// Material numbers
final static String[] materialNo = new String[] { "123", "234", "345",
"456", "567", "789", "012" };
private void getDataInList() {
for (int i = 0; i < 7; i++) {
Materials mats = new Materials(result, result);
mats.setMaterialName(material[i]);
// mats.setMaterialNo(material[i]);
materialList.add(mats);
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.information_activity);
name = (TextView) findViewById(R.id.name);
reg = (TextView) findViewById(R.id.reg);
product = (TextView) findViewById(R.id.product);
productNo = (TextView) findViewById(R.id.productNo);
accept = (Button) findViewById(R.id.btnAccept);
edit = (Button) findViewById(R.id.btnEdit);
list = (ListView) findViewById(R.id.list);
Bundle extras = getIntent().getExtras();
String selected_item = extras.getString("updateReg");
reg = (TextView) findViewById(R.id.reg);
reg.setText(selected_item);
Bundle extras1 = getIntent().getExtras();
String selected_item1 = extras1.getString("updateName");
name = (TextView) findViewById(R.id.name);
name.setText(selected_item1);
getDataInList();
edit.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
final AlertDialog.Builder popup = new AlertDialog.Builder(
InformationActivity.this);
popup.setTitle("Välj ny artikel");
// Search field
final EditText search = new EditText(context);
popup.setView(search);
search.setHint("Sök här...");
popup.setSingleChoiceItems(material, -1,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
materialList.get(which);
Toast.makeText(getApplicationContext(),
material[which], Toast.LENGTH_SHORT)
.show();
result = material[which];
}
});
// PositiveButton, updates the material info field.
popup.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
product.setText(result);
}
});
// NegativeButton, closes the pop-up.
popup.setNegativeButton("Avbryt",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
dialog.dismiss();
}
});
dialog = popup.create();
dialog.show();
}
});``
//Remove item
accept.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
finish();
}
});
}
答案 0 :(得分：0)
您不应该直接从视图中删除该项目，而是从其中显示的数据中删除。
例如，如果您的ListView正在显示ArrayList中的项目，只需从Activity B 中移除ArrayList中的项目，然后调用{{ 1}}返回包含适配器的Activity A 。
如果只能访问适配器（假设适配器扩展myAdapter.notifyDataSetChanged()），则可以通过访问ArrayList或覆盖remove()方法来删除项目。
此外，您可能必须覆盖有用的适配器方法，例如ArrayAdapter，getCount() ......
答案 1 :(得分：0)
感谢所有人。 由于remove row from another activity
，我找到了另一个解决方案A类
public class ListActivity extends Activity {
ListView list;
Button exit;
static List<ListItems> items = new ArrayList<ListItems>();
public static int deletePos;
static ListAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
list = (ListView) findViewById(R.id.list);
exit = (Button) findViewById(R.id.btnExit);
// Registration numbers
final String[] title = new String[] { "XMT 123", "KLE 456", "CKL 789",
"MRP 012", "DSV 345" };
// Name of the truck drivers
final String[] subtitle = new String[] { "Peter Lund", "Hans Larsson",
"Erik Petersson", "Bjørn Lundal", "Lars Svensson" };
items = new ArrayList<ListItems>();
for (int i = 0; i < title.length; i++) {
ListItems s = new ListItems(title[i], subtitle[i]);
items.add(s);
}
adapter = new ListAdapter(this, android.R.layout.simple_list_item_2,
items);
list.setAdapter(adapter);
list.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3) {
Intent intent = new Intent(ListActivity.this,
InformationActivity.class);
intent.putExtra("updateReg", title[position].toString());
intent.putExtra("updateName", subtitle[position].toString());
deletePos = position;
adapter.notifyDataSetChanged();
startActivity(intent);
}
});
exit.setOnClickListener(new OnClickListener() {
// Closes the application
@Override
public void onClick(View v) {
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
});
}
}
Class B
public class InformationActivity extends Activity {
TextView name;
TextView reg;
TextView product;
TextView productNo;
Button accept;
Button edit;
Button exit;
AlertDialog dialog;
ListView list;
String result;
EditText search;
Context context = InformationActivity.this;
ArrayList<Materials> materialList = new ArrayList<Materials>();
// Materials
final static String[] material = new String[] { "Betong", "Grus", "Järn",
"Metall", "Grus fin", "Grus grov", "Sten" };
// Material numbers
final static String[] materialNo = new String[] { "123", "234", "345",
"456", "567", "789", "012" };
private void getDataInList() {
for (int i = 0; i < 7; i++) {
Materials mats = new Materials(result, result);
mats.setMaterialName(material[i]);
// mats.setMaterialNo(material[i]);
materialList.add(mats);
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.information_activity);
name = (TextView) findViewById(R.id.name);
reg = (TextView) findViewById(R.id.reg);
product = (TextView) findViewById(R.id.product);
productNo = (TextView) findViewById(R.id.productNo);
accept = (Button) findViewById(R.id.btnAccept);
edit = (Button) findViewById(R.id.btnEdit);
list = (ListView) findViewById(R.id.list);
Bundle extras = getIntent().getExtras();
String selected_item = extras.getString("updateReg");
reg = (TextView) findViewById(R.id.reg);
reg.setText(selected_item);
Bundle extras1 = getIntent().getExtras();
String selected_item1 = extras1.getString("updateName");
name = (TextView) findViewById(R.id.name);
name.setText(selected_item1);
getDataInList();
edit.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
final AlertDialog.Builder popup = new AlertDialog.Builder(
InformationActivity.this);
popup.setTitle("Välj ny artikel");
// Search field
final EditText search = new EditText(context);
popup.setView(search);
search.setHint("Sök här...");
popup.setSingleChoiceItems(material, -1,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
materialList.get(which);
Toast.makeText(getApplicationContext(),
material[which], Toast.LENGTH_SHORT)
.show();
result = material[which];
}
});
// PositiveButton, updates the material info field.
popup.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
product.setText(result);
}
});
// NegativeButton, closes the pop-up.
popup.setNegativeButton("Avbryt",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
dialog.dismiss();
}
});
dialog = popup.create();
dialog.show();
}
});
// Remove item
accept.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
int deletePos = ListActivity.deletePos;
ListActivity.items.remove(deletePos);
ListActivity.adapter.notifyDataSetChanged();
finish();
}
});
}
}