Question

我有两个活动，第一个加载网址（简单webview），第二个活动从listview获取网址的ID，然后回调第一个加载网址的活动。我在第一个活动中使用onActivityResult()方法来获取额外数据（url id）。我的问题是当我想在方法onActivityResult()中的第一个Activity中显示ProgressDialog之后，在第二个活动中从ListView中选择项目后，我得到了一个ProgressDialog但它只显示了几秒钟（非常快）然后在完成加载之前消失URL（web视图）

这是我希望帮助我的拖曳活动的代码。

public class LibActivity extends Activity {

private ImageButton btnCategoriesList;

public static final int BOOK_CATEGORY_REQUEST_CODE = 1;

private WebView webView;

public ProgressDialog dialog;
private Handler handler;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.lib);

    handler = new Handler();
    dialog = ProgressDialog.show(this, "Loading", "Please wait", true, false);

    DisplayMetrics displaymetrics = new DisplayMetrics();

    webView = (WebView) findViewById(R.id.categoryWebView);
    webView.setWebViewClient(new CategoryItemWebViewClient());
    webView.getSettings().setJavaScriptEnabled(true);
    webView.loadUrl("http://maktabati.mobi/V3/store.php?catid=" + "91");

    btnCategoriesList = (ImageButton) findViewById(R.id.btn_category_list);

    btnCategoriesList.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            showBooksCategories();
        }
    });
}

/**
 * 
 */
protected void showBooksCategories() {
    Intent intent = new Intent(getApplicationContext(), BooksCategoriesActivity.class);
    startActivityForResult(intent, BOOK_CATEGORY_REQUEST_CODE);
}

/**
 * 
 * @author Jamil
 * 
 */
private class CategoryItemWebViewClient extends WebViewClient {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        if (url.contains("book")) {
            String bookId = url.substring(12);
            Intent intent = new Intent(getApplicationContext(), BookDetailActivity.class);
            intent.putExtra("BOOK_ID", bookId);
            startActivity(intent);
            view.stopLoading();
        }
        return super.shouldOverrideUrlLoading(view, url);
    }

    @Override
    public void onPageFinished(WebView view, String url) {
        super.onPageFinished(view, url);
        dialog.dismiss();
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, final Intent data) {
    if (requestCode == BOOK_CATEGORY_REQUEST_CODE) {
        if (resultCode == RESULT_OK) {
            dialog = ProgressDialog.show(this, "Loading", "Please wait", true);
            new Thread() {
                public void run() {
                    webView.loadUrl("http://maktabati.mobi/V3/store.php?catid=" + data.getStringExtra("CATEGORY_ID"));
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            dialog.dismiss();
                        }
                    });
                }
            }.start();

        }
    }
    super.onActivityResult(requestCode, resultCode, data);
}

第二项活动

public class BooksCategoriesActivity extends Activity {

ItemsCategoriesAdapter adapter;
ArrayList<Category> lstCategory;
Handler handlerProgressDialog;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.books_categories_list);
    handlerProgressDialog = new Handler();
    CategoryHandler handler = new CategoryHandler();
    ParserCreater parserCreater = new ParserCreater(handler);
    parserCreater.parse("http://maktabati.mobi/V3/getCategories.php");
    lstCategory = handler.getLstCategory();
    final ListView listView = (ListView) findViewById(R.id.categories_list);
    adapter = new ItemsCategoriesAdapter(lstCategory);
    listView.setAdapter(adapter);
    listView.setTextFilterEnabled(true);

    listView.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, final int position, long arg3) {
            Intent intent = new Intent(getApplicationContext(), LibActivity.class);
            intent.putExtra("CATEGORY_ID", lstCategory.get(position).getId());
            BooksCategoriesActivity.this.setResult(RESULT_OK, intent);
            finish();
        }
    });
}

由于

Answer 1

请尝试从onActivityResult函数中删除以下代码时会发生什么：

handler.post(new Runnable() {
                        @Override
                        public void run() {
                            dialog.dismiss();
                        }
                    });

应onPageFinished()之后调用webView.loadUrl()函数。

Answer 2

方法loadUrl()不是阻塞调用，因此您无需从后台线程调用它。如果要捕获页面加载完成的点，可以在WebviewClient上设置WebView对象来处理这方面的一系列回调。

此外，由于该调用未阻止，因此会立即返回，并且dismiss()方法几乎在show()时立即调用，这就是为什么您只是短暂显示它。

HTH

显示ProgressDialog onActivityResult

2 个答案: