android WebView控件使用事项

private WebView webview;

webview = (WebView) findViewById(R.id.webview);
webview.getSettings().setJavaScriptEnabled(true);
webview.getSettings().setDomStorageEnabled(true);
webview.getSettings().setSupportZoom(true);
webview.getSettings().setBuiltInZoomControls(true);
webview.getSettings().setDatabaseEnabled(true);
String databasePath = this.getApplicationContext().getDir("database", Context.MODE_PRIVATE).getPath();
webview.getSettings().setDatabasePath(databasePath);

1,webView 下载功能

webview.setDownloadListener(new DownloadListener() {

@Override
public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
// TODO Auto-generated method stub
Uri uri = Uri.parse(url);
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
});

2，webView加载url

webview.loadUrl(h5urlString);
webview.setWebViewClient(new HelloWebViewClient());

3,webView 显示进度条

webview.setWebChromeClient(new WebChromeClient() {

@Override

public void onProgressChanged(WebView view, int newProgress) {
// TODO Auto-generated method stub
super.onProgressChanged(view, newProgress);
pb_detail.setProgress(newProgress);
pb_detail.postInvalidate();
if (newProgress == 100) {
pb_detail.setVisibility(View.GONE);
}
}

@Override
public void onReceivedTitle(WebView view, String title) {
// TODO Auto-generated method stub
super.onReceivedTitle(view, title);
// tv_title.setText(title);
}
});

4，webView加载不了h5时 显示错误页面

private class HelloWebViewClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}

@Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
// TODO Auto-generated method stub
super.onReceivedError(view, errorCode, description, failingUrl);
view.loadData(Constant.Error_Html, "text/html;charset=UTF-8", null);
}

@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
}

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

5，当按物理返回键时，webView 页面一层一层返回

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
if (keyCode == KeyEvent.KEYCODE_BACK) {
if (webview.canGoBack()) {
webview.goBack();
return true;
}
}
return super.onKeyDown(keyCode, event);
}