Question

我有两项活动 - MainActivity和Settings。通过按MainActivity中的菜单按钮并选择＆＃34;设置＆＃34;来访问设置。在“设置”中，我有一个复选框，我想保存状态并将其传递给MainActivity，如果选中它，它应该显示＆＃34;这是真的＆＃34;如果未选中，则应显示＆＃34;这是假的＃34;。但是现在，当我勾选复选框并按下设置中的后退按钮时，没有任何反应。当我再次回到设置时，我意识到复选框并没有保存我强加给它的状态。谁能告诉我我做错了什么？我是java的新手，我希望得到你的指导。

我的MainActivity.java

package sp.com;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.widget.Button;
import android.widget.TextView;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.RadioGroup;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import android.app.TabActivity;
import android.widget.TabHost;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.content.Context;
import android.database.Cursor;
import android.support.v4.widget.CursorAdapter;
import android.media.MediaPlayer;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.view.KeyEvent;

public class MainActivity extends Activity {


    Button button;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;

    }

     private void LoadPreferences(){   
           SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
           boolean isChecked = sharedPref.getBoolean("checked", false);
           if (isChecked == true)
           {
               Toast.makeText(getApplicationContext(), "this is true.",
                       Toast.LENGTH_LONG).show();
           } else {
               Toast.makeText(getApplicationContext(), "this is false",
                       Toast.LENGTH_LONG).show();
           }
       }

    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.setting:
            Intent intent = new Intent(MainActivity.this, Settings.class);
            startActivity(intent);

            break;

        }
        return super.onOptionsItemSelected(item);
    }

}

我的设置.java

package sp.com;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.view.View.OnClickListener;

import android.content.SharedPreferences.Editor;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.preference.PreferenceManager;
import android.view.KeyEvent;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.Toast;
import android.widget.CompoundButton.OnCheckedChangeListener;

public class Settings extends Activity {

    CheckBox chkbox;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.xml.preferences);

        chkbox = (CheckBox) findViewById(R.id.backmusic);

        chkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                // TODO Auto-generated method stub
                SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
                SharedPreferences.Editor editor = sharedPref.edit();
                editor.putBoolean("checked", isChecked);
                editor.commit();
            }
        });

    }



}

我的清单

 <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="sp.com"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="17" />

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/my_icon"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="sp.com.SplashScreen"
            android:label="@string/app_name"
            android:screenOrientation="portrait"
            android:theme="@android:style/Theme.Black.NoTitleBar" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="sp.com.WebActivity"
            android:label="@string/app_name" />
        <activity
            android:name="sp.com.MainActivity"
            android:label="@string/app_name" >
        </activity>
        <activity
            android:name="sp.com.Settings"
            android:label="@string/app_name" >
        </activity>

    </application>

</manifest>

先谢谢你们。问候，史蒂夫

Answer 1

如果首选项值为true，则需要检查CheckBox，因此在此声明之后

chkbox = (CheckBox) findViewById(R.id.backmusic);

添加以下内容

SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
chkbox.setChecked(sharedPref.getBoolean("checked", false));

在您的MainActivity中，您需要调用LoadPreferences方法

@Override
protected void onResume() {
    super.onResume();
    LoadPreferences();
}

保存并将复选框值传递给其他活动

1 个答案: