Android 如何在加载前使用“后退”按钮关闭progressbar?
我正在使用web视图的进度条。我需要在加载页面之前停止进度条。我按了后退按钮,但在加载之间没有工作Android 如何在加载前使用“后退”按钮关闭progressbar?,android,android-progressbar,Android,Android Progressbar,我正在使用web视图的进度条。我需要在加载页面之前停止进度条。我按了后退按钮,但在加载之间没有工作 public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.webview);
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.webview);
mWebView = (WebView) findViewById(R.id.webview);
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
final AlertDialog alertDialog = new AlertDialog.Builder(this).create();
progressBar =new ProgressDialog(this);
progressBar.setCancelable(true);
progressBar.show();
mWebView.setWebViewClient(new WebViewClient() {
public boolean shouldOverrideUrlLoading(WebView view, String url) {
Log.i("TEST", "Processing webview url click...");
view.loadUrl(url);
return true;
}
public void onPageFinished(WebView view, String url) {
Log.i("TEST", "Finished loading URL: " +url);
if (progressBar.isShowing()) {
progressBar.dismiss();
}
}
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
Log.e("TEST", "Error: " + description);
Toast.makeText(getApplicationContext(), "Oh no! " + description, Toast.LENGTH_SHORT).show();
alertDialog.setTitle("Error");
alertDialog.setMessage(description);
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
return;
}
});
alertDialog.show();
}
});
mWebView.loadUrl("http://www.google.com");
}
对于后退按钮测试,我使用这个
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
Toast.makeText(getApplicationContext(),"hi", Toast.LENGTH_LONG).show();
return true;
}
return super.onKeyDown(keyCode, event);
}
使用多线程实现进度和可视化显示,使用UIWorker线程Hi 请看这个
progressBar = new ProgressDialog(this);
progressBar.setCancelable(true);
progressBar.setOnCancelListener(new OnCancelListener() {
public void onCancel(DialogInterface arg0) {
if(progressBar.isShowing())
progressBar.dismiss();
finish();
}
});
progressBar.setMessage("Loading...");
progressBar.show();
如果我是你,我会使用AsyncTask加载URL的数据,并在其间显示ProgressDialog
- 在开始时,生成一个不同的线程来获取URL的内容
- 开始显示ProgressDialog
- 当您拥有线程返回的URL的数据时,将其加载到webView中
- 关闭ProgressDialog
要在不同的线程中运行,请检查AsyncTask。我已经使用AsnyTask和简单处理程序实现了代码,但同样的问题,您还有其他想法吗?比如我怎样才能杀死堆栈中的任何活动?