你好这段代码中的 friend 我正在尝试编辑列表项的文本并保存列表项中的最新文本，即使在此处关闭应用程序后我们也可以成功地检索带有编辑文本选项的对话框中的文本已经在 listitem 中，只需将预定义的更改为任何文本 帮忙解决这件小事 提前致谢
MainActivity.java:
package com.example.vks_module;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.jar.Attributes.Name;
import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
private ListView mainListView;
private ArrayAdapter<String> listAdapter;
final Context context = this;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mainListView = (ListView) findViewById(R.id.lv1);
String[] planets = new String[] { "Mercury", "Venus", "Earth", "Mars",
"Jupiter", "Saturn", "Uranus", "Neptune" };
final ArrayList<String> planetList = new ArrayList<String>();
planetList.addAll(Arrays.asList(planets));
listAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, planetList);
mainListView.setAdapter(listAdapter);
mainListView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int pos,
long id) {
String message = planetList.get(pos);
final int positions = mainListView.getSelectedItemPosition();
final Dialog dialog = new Dialog(context);
dialog.setContentView(R.layout.customdialog);
dialog.setTitle("Change the name");
final TextView plan_names = (TextView) dialog
.findViewById(R.id.name);
Button set = (Button) dialog.findViewById(R.id.Set);
plan_names.setText(message);
set.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String name = plan_names.getText().toString();
int pos = positions;
if (!name.isEmpty() && name.length() > 0) {
// remove
listAdapter.remove(planetList.get(pos));
// insert the updated one
listAdapter.insert(name, mainListView.getSelectedItemPosition());
listAdapter.notifyDataSetChanged();
} else {
Toast.makeText(getApplicationContext(),
"Are you serious", Toast.LENGTH_SHORT)
.show();
}
}
});
dialog.show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
**activitymain.xml**
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.vks_module.MainActivity" >
<ListView
android:id="@+id/lv1"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_centerHorizontal="true"
android:padding="10dp"
/>
</RelativeLayout>
**customedailog.xml**
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/holo_blue_light"
android:orientation="vertical" >
<EditText
android:id="@+id/name"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_centerHorizontal="true"
android:gravity="center_horizontal"
android:layout_marginTop="100dp"
android:background="@android:color/transparent" />
<Button
android:id="@+id/Set"
android:layout_below="@+id/name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="20dp"
android:text="SET" />
</RelativeLayout>
**LOGCAT**
03-28 00:17:38.767: D/AndroidRuntime(26713): Shutting down VM
03-28 00:17:38.774: E/AndroidRuntime(26713): FATAL EXCEPTION: main
03-28 00:17:38.774: E/AndroidRuntime(26713): Process: com.example.vks_module, PID: 26713
03-28 00:17:38.774: E/AndroidRuntime(26713): java.lang.ArrayIndexOutOfBoundsException: length=10; index=-1
03-28 00:17:38.774: E/AndroidRuntime(26713): at java.util.ArrayList.get(ArrayList.java:310)
03-28 00:17:38.774: E/AndroidRuntime(26713): at com.example.vks_module.MainActivity$1$1.onClick(MainActivity.java:71)
03-28 00:17:38.774: E/AndroidRuntime(26713): at android.view.View.performClick(View.java:5204)
03-28 00:17:38.774: E/AndroidRuntime(26713): at android.view.View$PerformClick.run(View.java:21153)
03-28 00:17:38.774: E/AndroidRuntime(26713): at android.os.Handler.handleCallback(Handler.java:739)
03-28 00:17:38.774: E/AndroidRuntime(26713): at android.os.Handler.dispatchMessage(Handler.java:95)
03-28 00:17:38.774: E/AndroidRuntime(26713): at android.os.Looper.loop(Looper.java:148)
03-28 00:17:38.774: E/AndroidRuntime(26713): at android.app.ActivityThread.main(ActivityThread.java:5417)
03-28 00:17:38.774: E/AndroidRuntime(26713): at java.lang.reflect.Method.invoke(Native Method)
03-28 00:17:38.774: E/AndroidRuntime(26713): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
03-28 00:17:38.774: E/AndroidRuntime(26713): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
最佳答案
如果您看到方法的文档 getSelectedItemPosition() ，如果未选择任何内容，则返回 INALID_ROW_ID(其值为 -1)。我认为当您在 ListView 中选择一个项目时，您正在启动一个 Dialog 获得焦点，而 ListView 中的项目未被选中这就是为什么代码中的 mainListView.getSelectedItemPosition() 总是返回 -1 的原因。而是使用方法 onItemClick() 中的参数 pos，如下所示。
mainListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int pos,
long id) {
String message = planetList.get(pos);
final int positions = pos; //change here
final Dialog dialog = new Dialog(context);
dialog.setContentView(R.layout.customdialog);
dialog.setTitle("Change the name");
final TextView plan_names = (TextView) dialog
.findViewById(R.id.name);
Button set = (Button) dialog.findViewById(R.id.Set);
plan_names.setText(message);
set.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String name = plan_names.getText().toString();
if (!name.isEmpty() && name.length() > 0) {
// remove
listAdapter.remove(planetList.get(positions)); //change here
// insert the updated one
listAdapter.insert(name, positions); //change here
listAdapter.notifyDataSetChanged();
} else {
Toast.makeText(getApplicationContext(),
"Are you serious", Toast.LENGTH_SHORT)
.show();
}
dialog.dismiss(); //add this to dismiss dialogue after entering the string
}
});
dialog.show();
}
});
如果你想保存更改并在应用程序重新启动后获取新值，你应该将新值保存在数据库中并使用它们在你的onCreate() 中填充你的数组/数组列表> 方法。
关于android - 如何动态编辑和保存列表项文本？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36251400/