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Android 如何动态编辑和保存listitem文本?_Android_Database_Sharedpreferences - Fatal编程技术网

Android 如何动态编辑和保存listitem文本?

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

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.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();

            }

        });