LinearLayout（linearLayout）如何在我的班級中可見？

Question

我有兩個類，“ XMLParser.java”擴展了活動並導入了“ ClassAsyncTask.java”（從我自己的庫中）。 現在我的XMLParser中有問題，它說linearlayout不可見，如何解決此錯誤？ 謝謝

public class XMLParser extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ClassAsyncTask aObj = new ClassAsyncTask(
            "http://www.androidpeople.com/wp-content/uploads/2010/06/example.xml", this);
    aObj.execute();

    //THIS IS MY PROBLEM, "The field ClassAsyncTask.linearLayout is not visible"
    aObj.linearLayout = new LinearLayout(this);
    aObj.linearLayout.setOrientation(1);

    /* Set the ContentView to layout for display */
    this.setContentView(aObj.linearLayout);

}

}

這是XMLParser.java導入的ClassAsyncTask.java（來自我自己的庫）

public class ClassAsyncTask extends AsyncTask<String, Void, String> {


String targetURL;
TextView name[], website[], category[];
LinearLayout linearLayout;
Context context;

public ClassAsyncTask(String site, Context ctx){
    targetURL = site;
    context = ctx;
}


@Override
protected String doInBackground(String... urls) {

    try {

        /* Handling XML */
        SAXParserFactory spf = SAXParserFactory.newInstance();
        SAXParser sp = spf.newSAXParser();
        XMLReader xr = sp.getXMLReader();

        /* Send URL to parse XML Tags */
        URL sourceUrl = new URL(targetURL);

        /* Create handler to handle XML Tags ( extends DefaultHandler ) */
        MyXMLHandler myXMLHandler = new MyXMLHandler();
        xr.setContentHandler(myXMLHandler);
        xr.parse(new InputSource(sourceUrl.openStream()));

    } catch (Exception e) {
        System.out.println("XML Pasing Excpetion = " + e);
    }
    return null;
}

/* Return-value from doInBackground */
protected void onPostExecute(String result) {

    /* Get result from MyXMLHandler SitlesList Object */
    SiteList sitesList = MyXMLHandler.sitesList;

    /* Assign TextView array length by arrayList size */
    name = new TextView[sitesList.getName().size()];
    website = new TextView[sitesList.getName().size()];
    category = new TextView[sitesList.getName().size()];

    int h = sitesList.getName().size();
    /* Set the result text in TextView and add it to layout */
    for (int i = 0; i < h; i++) {

        name[i]= new TextView(getApplicationContext());
        name[i].setText("Name = " + sitesList.getName().get(i));
        website[i]= new TextView(getApplicationContext());
        website[i].setText("Website = " + sitesList.getWebsite().get(i));
        category[i]= new TextView(getApplicationContext());
        category[i].setText("Website Category = " + sitesList.getCategory().get(i));
        linearLayout.addView(name[i]);
        linearLayout.addView(website[i]);
        linearLayout.addView(category[i]);

    }
}

}

Answer 1

我建議您不要以這種方式訪問LinearLayout ，而應使用它的設置方法和獲取方法。

在您的ClassAsyncTask.java

LinearLayout linearLayout;

public void setLinearLayout(LinearLayout linearLayout){
    this.linearLayout = linearLayout;
}


public LinearLayout getLinearLayout(){
    return linearLayout;
}

然后在XMLParser.java ，只需執行LinearLayout myLinearLayout = aobj.getLinearLayout()對布局進行所需的編輯，然后通過aobj.setLinearLayout(myLinearLayout)將其返回給ClassAsyncTask aobj.setLinearLayout(myLinearLayout) 。