Question

我只是实现SharedPreferences。

这是我的Java代码

    SharedPreferences sp = getSharedPreferences("adsBannerFull", MainHelloballi.MODE_PRIVATE);
    SharedPreferences.Editor editor = sp.edit();
    editor.putBoolean("isItFirstTime", true);
    editor.commit();

    if (sp.getBoolean("isItFirstTime", false)){
    closeButton = (ImageView) findViewById(R.id.close_button);
    adsbannerFull = (WebView) findViewById(R.id.adsbanner_full);
    adsbannerFull.setVisibility(View.VISIBLE);
    adsbannerFull.setWebViewClient(new WebViewClient(){
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url){
            view.loadUrl(url);
            return true;
        }
    }); 

    adsbannerFull.getSettings().setLoadsImagesAutomatically(true); 
    adsbannerFull.getSettings().setDatabaseEnabled(true);
    adsbannerFull.getSettings().setAppCacheEnabled(true); 
    adsbannerFull.getSettings().setDomStorageEnabled(true); 
    adsbannerFull.getSettings().setJavaScriptEnabled(true);

    adsbannerFull.loadUrl("http://api.hellobaliapps.com/ads/main_ads_big");
    }
    else {
        adsbannerFull = (WebView) findViewById(R.id.adsbanner_full);
        adsbannerFull.setVisibility(View.GONE);
    }

我将此代码放在onCreate上。因此，第一次调用它的Activity将显示adsbannerFull，但当用户转到Y Activity时，请返回X Activity adsbannerFull不再显示。

我按照本指南http://androidexample.com/Android_SharedPreferences_Basics/index.php?view=article_discription&aid=126&aaid=146进行了改进。但它不起作用，但没有错误。

任何人都可以帮助我？

Answer 1

SharedPreferences sp = getSharedPreferences("adsBannerFull", MainHelloballi.MODE_PRIVATE);

/* Initially, sp would be null and later on, sp.getBoolean would be false.
   If sp is null or sp.getboolean is true, the below statement block would be executed.
*/

if (sp.getBoolean("isItFirstTime", true)){

/*First time only this statement block would be called. 
All other times this statement block would never be called.*/
SharedPreferences.Editor editor = sp.edit();
editor.putBoolean("isItFirstTime", false);
editor.commit();

closeButton = (ImageView) findViewById(R.id.close_button);
adsbannerFull = (WebView) findViewById(R.id.adsbanner_full);
// Remaining code here .........

}// End of if block

/// Remaining code here..........

Answer 2

尝试这种方式：

声明：

  private SharedPreferences prefs;
  private SharedPreferences.Editor editor;

初始化：

 prefs = getPreferences(Context.MODE_PRIVATE);
 editor = prefs.edit();

放价值：

editor.putBoolean("isItFirstTime", true);
editor.commit();

随时随地获取：

 Boolean bool_val=prefs.getBoolean("isItFirstTime",false);

现在你检查你的情况：

 if(bool_val)
 {
     true_Value;
 }
 else
 {
    false_Value;
 }

如果需要，请使用System.out.println（...）;

进行检查

Android：SharedPreferences不起作用

2 个答案: