java - 共有設定

Question

アプリで SharedPrefs を使用しようとしています。別の設定アクティビティからメールアドレスとパスワードを取得したいだけです。実装しました

package com.overclockerz.webtest;

import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.widget.EditText;

public class SettingScreen extends Activity {
    static EditText username;
    static EditText password;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.setting_screen);
    username = (EditText) findViewById(R.id.username);
    password = (EditText) findViewById(R.id.password);

    SharedPreferences settings =  
            getSharedPreferences("APP_PREFS", MODE_PRIVATE); 
    SharedPreferences.Editor prefEditor = settings.edit();
    prefEditor.putString("Username", username.getText().toString());
    prefEditor.putString("Password", username.getText().toString());
    prefEditor.commit();        

}

}

そして、パッケージ com.overclockerz.webtest; で取得しようとしました。

import org.apache.http.util.EncodingUtils;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.CookieManager;
import android.webkit.WebSettings;
import android.webkit.WebSettings.LayoutAlgorithm;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends Activity implements OnItemSelectedListener,
        OnClickListener {
String query = "fldUsername=" + username + "&fldPassword=" + password + "&ut=3";
String username = prefs.getString("Username");
String password = getText(R.id.password).toString();

    @SuppressLint("SetJavaScriptEnabled")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this); 
        // then you use
        prefs.getBoolean("keystring", true);
        //there are also methods to put strings,float, longs, ints





        WebView myWebView = (WebView) findViewById(R.id.webview);
        WebSettings webSettings = myWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setUserAgentString("SMUK");
        //myWebView.setInitialScale(100);
        //myWebView.setPadding(0, 0, 0, 0);
        CookieManager.getInstance().setAcceptCookie(true);

        // webSettings.setUseWideViewPort(true);
        webSettings.setLayoutAlgorithm(LayoutAlgorithm.SINGLE_COLUMN);
        myWebView.setWebViewClient(new WebViewClient());
        myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                EncodingUtils.getBytes(query,"BASE64"));
        Toast.makeText(getApplicationContext(), query, Toast.LENGTH_LONG)
         .show();
        Spinner spinner = (Spinner) findViewById(R.id.menu_spinner);
        // Create an ArrayAdapter using the string array and a default spinner
        // layout
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
                this, R.array.spinner_links,
                android.R.layout.simple_spinner_item);
        // Specify the layout to use when the list of choices appears
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        // Apply the adapter to the spinner
        spinner.setAdapter(adapter);

        spinner.setOnItemSelectedListener(this);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        WebView myWebView = (WebView) findViewById(R.id.webview);
        // Check if the key event was the Back button and if there's history
        if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
            myWebView.goBack();
            return true;
        }
        // If it wasn't the Back key or there's no web page history, bubble up
        // to the default
        // system behavior (probably exit the activity)
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;

    }

    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
            long arg3) {
        WebView myWebView = (WebView) findViewById(R.id.webview);
        switch (arg2) {
        case 0:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView.loadUrl("http://test.schoolmilkuk.co.uk/parent-home");
            break;
        case 1:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView
                    .loadUrl("http://test.schoolmilkuk.co.uk/parent-change-pass");
            break;
        case 2:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView
                    .loadUrl("http://test.schoolmilkuk.co.uk/parent-add-child");
            break;
        case 3:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView
                    .loadUrl("http://test.schoolmilkuk.co.uk/parent-children-list");
            break;
        case 4:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView.loadUrl("http://test.schoolmilkuk.co.uk/parent-order");
            break;
        case 5:
            myWebView.clearCache(true);
            Toast.makeText(getApplicationContext(), "Cache Cleared :)",
                    Toast.LENGTH_LONG).show();
            break;
        default:
            myWebView.loadUrl("http://test.schoolmilkuk.co.uk/parent-home");
            break;
        }
    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.settings_menu:
            startActivity(new Intent(this, SettingScreen.class));
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }

}

String username = prefs.getString("Username", "Username") は、「username」を提供しているため、ユーザーが設定した変数を使用していないため意味がありません。私は非常に混乱しています。

Blackbelt のアドバイスに従った後(そのすべてが非常に高く評価されています)、コードを次のように修正しましたが、null ポインター例外が発生していますか?

package com.overclockerz.webtest;

import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.widget.EditText;

public class SettingScreen extends Activity {
    static EditText username;
    static EditText password;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.setting_screen);
        username = (EditText) findViewById(R.id.username);
        password = (EditText) findViewById(R.id.password);

        SharedPreferences settings =  
                getSharedPreferences("APP_PREFS", MODE_PRIVATE); 
        SharedPreferences.Editor prefEditor = settings.edit();
        prefEditor.putString("Username", username.getText().toString());
        prefEditor.putString("Password", username.getText().toString());
        prefEditor.commit();        

    }

}

package com.overclockerz.webtest;

import org.apache.http.util.EncodingUtils;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.CookieManager;
import android.webkit.WebSettings;
import android.webkit.WebSettings.LayoutAlgorithm;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends Activity implements OnItemSelectedListener,
        OnClickListener {
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
String username = prefs.getString("Username", "default");
String password = prefs.getString("Password", "default");

String query = "fldUsername=" + username + "&fldPassword=" + password + "&ut=3";
    @SuppressLint("SetJavaScriptEnabled")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);



        WebView myWebView = (WebView) findViewById(R.id.webview);
        WebSettings webSettings = myWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setUserAgentString("SMUK");
        //myWebView.setInitialScale(100);
        //myWebView.setPadding(0, 0, 0, 0);
        CookieManager.getInstance().setAcceptCookie(true);

        // webSettings.setUseWideViewPort(true);
        webSettings.setLayoutAlgorithm(LayoutAlgorithm.SINGLE_COLUMN);
        myWebView.setWebViewClient(new WebViewClient());
        myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                EncodingUtils.getBytes(query,"BASE64"));
        Toast.makeText(getApplicationContext(), query, Toast.LENGTH_LONG)
         .show();
        Spinner spinner = (Spinner) findViewById(R.id.menu_spinner);
        // Create an ArrayAdapter using the string array and a default spinner
        // layout
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
                this, R.array.spinner_links,
                android.R.layout.simple_spinner_item);
        // Specify the layout to use when the list of choices appears
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        // Apply the adapter to the spinner
        spinner.setAdapter(adapter);

        spinner.setOnItemSelectedListener(this);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        WebView myWebView = (WebView) findViewById(R.id.webview);
        // Check if the key event was the Back button and if there's history
        if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
            myWebView.goBack();
            return true;
        }
        // If it wasn't the Back key or there's no web page history, bubble up
        // to the default
        // system behavior (probably exit the activity)
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;

    }

    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
            long arg3) {
        WebView myWebView = (WebView) findViewById(R.id.webview);
        switch (arg2) {
        case 0:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView.loadUrl("http://test.schoolmilkuk.co.uk/parent-home");
            break;
        case 1:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView
                    .loadUrl("http://test.schoolmilkuk.co.uk/parent-change-pass");
            break;
        case 2:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView
                    .loadUrl("http://test.schoolmilkuk.co.uk/parent-add-child");
            break;
        case 3:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView
                    .loadUrl("http://test.schoolmilkuk.co.uk/parent-children-list");
            break;
        case 4:
            myWebView.postUrl("http://test.schoolmilkuk.co.uk/parents-login",
                    EncodingUtils.getBytes(query,"BASE64"));
            myWebView.loadUrl("http://test.schoolmilkuk.co.uk/parent-order");
            break;
        case 5:
            myWebView.clearCache(true);
            Toast.makeText(getApplicationContext(), "Cache Cleared :)",
                    Toast.LENGTH_LONG).show();
            break;
        default:
            myWebView.loadUrl("http://test.schoolmilkuk.co.uk/parent-home");
            break;
        }
    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.settings_menu:
            startActivity(new Intent(this, SettingScreen.class));
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }

}

score 2 · Accepted Answer

PreferenceManager.getDefaultSharedPreferences

と

SharedPreferences settings =  
            getSharedPreferences("APP_PREFS", MODE_PRIVATE);

別のものを返します。

前者はデフォルトのファイル名 (パッケージ名のようなもの) を使用し、後者は名前を必要とします。混乱しないでください。の 2 番目のパラメーターgetString()は既定値です。たとえば、いくつかの調味料が満たされていないことを確認するために使用できます。

score 1 · Accepted Answer

getStringのドキュメントを読み直してください。defValueプリファレンスに値がない場合にのみ返されます。null2 番目の引数として渡すことができます。取得した場合nullは、ユーザー名がまだ設定されていないことを意味します。
また、ではなく、何らかのアクションの設定にユーザー名を保存する必要がありますonCreate。たとえば、ボタン「OK」を作成しonClick、このボタンのユーザー名を保存します。

score 0 · Accepted Answer

複数の共有設定が必要な場合は、名前を入れてください。

SharedPreferences sp = getApplication().getSharedPreferences("someName", Context.MODE_PRIVATE);

1つだけ必要な場合

SharedPrefrences sp = PreferenceManager.getDefaultSharedPreferences(this);

java - 共有設定

3 に答える 3

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