Android 如何动态编辑和保存listitem文本?
你好,朋友,在这段代码中,我正在尝试编辑listitem的文本,并将最新文本保存在listitem中,即使在应用程序关闭后,我们也可以在对话框中成功检索文本,其中的编辑文本选项已经在listitem中,只需将预定义文本更改为任何文本 帮我做这件小事 提前谢谢 MainActivity.java:Android 如何动态编辑和保存listitem文本?,android,database,sharedpreferences,Android,Database,Sharedpreferences,你好,朋友,在这段代码中,我正在尝试编辑listitem的文本,并将最新文本保存在listitem中,即使在应用程序关闭后,我们也可以在对话框中成功检索文本,其中的编辑文本选项已经在listitem中,只需将预定义文本更改为任何文本 帮我做这件小事 提前谢谢 MainActivity.java: package com.example.vks_module; import java.util.ArrayList; import java.util.Arrays; import java.uti
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)
package com.example.vks_模块;
导入java.util.ArrayList;
导入java.util.array;
导入java.util.jar.Attributes.Name;
导入android.app.Activity;
导入android.app.Dialog;
导入android.content.Context;
导入android.content.Intent;
导入android.os.Bundle;
导入android.view.Menu;
导入android.view.MenuItem;
导入android.view.view;
导入android.view.view.OnClickListener;
导入android.widget.AdapterView;
导入android.widget.AdapterView.OnItemClickListener;
导入android.widget.ArrayAdapter;
导入android.widget.Button;
导入android.widget.ListView;
导入android.widget.TextView;
导入android.widget.Toast;
公共类MainActivity扩展了活动{
私有ListView主ListView;
专用阵列适配器列表适配器;
最终上下文=此;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mainListView=(ListView)findViewById(R.id.lv1);
字符串[]行星=新字符串[]{“水星”、“金星”、“地球”、“火星”,
“木星”、“土星”、“天王星”、“海王星”};
最终ArrayList planetList=新ArrayList();
planetList.addAll(Arrays.asList(planets));
listAdapter=new ArrayAdapter(此,
android.R.layout.simple_list_item_1,planetList);
mainListView.setAdapter(listAdapter);
mainListView.setOnItemClickListener(新的OnItemClickListener(){
@凌驾
public void onItemClick(AdapterView父级、视图、int pos、,
长id){
字符串消息=planetList.get(pos);
final int positions=mainListView.getSelectedItemPosition();
最终对话框=新对话框(上下文);
setContentView(R.layout.customdialog);
dialog.setTitle(“更改名称”);
最终文本视图平面图名称=(文本视图)对话框
.findviewbyd(R.id.name);
按钮集=(按钮)dialog.findViewById(R.id.set);
plan_names.setText(消息);
set.setOnClickListener(新的OnClickListener(){
@凌驾
公共void onClick(视图v){
String name=plan_names.getText().toString();
int pos=位置;
如果(!name.isEmpty()&&name.length()>0){
//除去
移除(planetList.get(pos));
//插入更新的一个
insert(名称,mainListView.getSelectedItemPosition());
listAdapter.notifyDataSetChanged();
}否则{
Toast.makeText(getApplicationContext(),
“你是认真的吗”,吐司。长度(短)
.show();
}
}
});
dialog.show();
}
});
}
@凌驾
公共布尔onCreateOptions菜单(菜单){
//为菜单充气;这会将项目添加到操作栏(如果存在)。
getMenuInflater().充气(R.menu.main,menu);
返回true;
}
@凌驾
公共布尔值onOptionsItemSelected(菜单项项){
//处理操作栏项目单击此处。操作栏将
//自动处理Home/Up按钮上的点击,只要
//在AndroidManifest.xml中指定父活动时。
int id=item.getItemId();
if(id==R.id.action\u设置){
返回true;
}
返回super.onOptionsItemSelected(项目);
}
}
**activitymain.xml**
**customedailog.xml**
**LOGCAT**
03-28 00:17:38.767:D/AndroidRuntime(26713):关闭虚拟机
03-28 00:17:38.774:E/AndroidRuntime(26713):致命异常:主
03-28 00:17:38.774:E/AndroidRuntime(26713):进程:com.example.vks_模块,PID:26713
03-28 00:17:38.774:E/AndroidRuntime(26713):java.lang.ArrayIndexOutOfBoundsException:length=10;索引=-1
03-28 00:17:38.774:E/AndroidRuntime(26713):位于java.util.ArrayList.get(ArrayList.java:310)
03-28 00:17:38.774:E/AndroidRuntime(26713):在com.example.vks_module.MainActivity$1$1.onClick(MainActivity.java:71)
03-28 00:17:38.774:E/AndroidRuntime(26713):在android.view.view.performClick(view.java:5204)上
03-28 00:17:38.774:E/AndroidRuntime(26713):在android.view.view$PerformClick.run(view.java:21153)
03-28 00:17:38.774:E/AndroidRuntime(26713):在android.os.Handler.handleCallback(Handler.java:739)上
03-28 00:17:38.774:E/AndroidRuntime(26713):在android.os.Handler.dispatchMessage(Handler.java:95)上
03-28 00:17:38.774:E/AndroidRuntime(26713):在android.os.Looper.loop(Looper.java:148)上
03-28 00:17:38.774:E/AndroidRuntime(26713):位于android.app.ActivityThread.main(ActivityThread.java:5417)
03-28 00:17:38.774:E/AndroidRuntime(26713):位于java.lang.reflect.Method.invoke(本机方法)
03-28 00:17:38.774:E/AndroidRuntime(26713):在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
03-28 00:17:38.774:E/AndroidRuntime(26713):位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
问题就在眼前
final int positions = mainListView.getSelectedItemPosition();
所以,
当您单击ListView项目时,它不会将其状态更改为“选定”,因此,当事件发生时,您会:
mainListView.getSelectedItem()
int pos = positions;
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();
}
});