我有一个使用浏览器字段连接到网页的应用。 一切正常，模拟器显示正确的页面。
如果我将模拟器网络属性设置为“Out of Coverage”并单击我的网页中的链接，那么我得到一个例外 - 在BrowserFieldConnectionManagerImpl
如何捕获此异常以便我采取适当的措施？
该应用正在使用BlackBerry SDK
代码在这里：
public final class example_Screen扩展了MainScreen {
// Create the ErrorHandler class
public class MyBrowserFieldErrorHandler extends BrowserFieldErrorHandler {
protected MyBrowserFieldErrorHandler(BrowserField browserField){
super(browserField);
}
public void displayContentError(String url, String errorMessage) {
System.out.println("JERRY: displayContentError" + url);
System.out.println("JERRY: displayContentError" + errorMessage);
}
public void displayContentError(String url, InputConnection connection, Throwable t) {
displayContentError(url, t.getMessage());
}
public void navigationRequestError(BrowserFieldRequest request, Throwable t) {
displayContentError(request.getURL(), t.getMessage());
}
public void requestContentError(BrowserFieldRequest request, Throwable t) {
displayContentError(request.getURL(), t.getMessage());
}
public InputConnection resourceRequestError(BrowserFieldRequest request, Throwable t) {
displayContentError(request.getURL(), t.getMessage());
InputConnection connection = null;
return connection;
}
}
/**
* Creates a new example_Screen object
*/
public example_Screen() {
GIFEncodedImage ourAnimation = (GIFEncodedImage) GIFEncodedImage.getEncodedImageResource("2.gif");
AnimatedGIFField _ourAnimation = new AnimatedGIFField(ourAnimation, Field.FIELD_HCENTER + Field.FIELD_VCENTER);
this.add(_ourAnimation);
LabelField _ourLabelField = new LabelField("Updating ...", Field.FIELD_HCENTER + Field.FIELD_VCENTER);
this.add(_ourLabelField);
int anim_ht = _ourAnimation.getPreferredHeight();
int label_ht = _ourLabelField.getPreferredHeight();
EncodedImage ei = EncodedImage.getEncodedImageResource("img/menu.png");
int currentWidthFixed32 = Fixed32.toFP(ei.getWidth());
int currentHeightFixed32 = Fixed32.toFP(ei.getHeight());
int displayWidthFixed32 = Fixed32.toFP(Display.getWidth());
int displayHeightFixed32 = Fixed32.toFP((Display.getHeight() - anim_ht - label_ht));
int scaleXFixed32 = Fixed32.div(currentWidthFixed32, displayWidthFixed32);
int scaleYFixed32 = Fixed32.div(currentHeightFixed32, displayHeightFixed32);
ei = ei.scaleImage32(scaleXFixed32, scaleYFixed32);
BitmapField bmp = new BitmapField(ei.getBitmap(), Field.FIELD_HCENTER + Field.FIELD_VCENTER);
add(bmp);
BrowserFieldConfig myBrowserFieldConfig = new BrowserFieldConfig();
myBrowserFieldConfig.setProperty(BrowserFieldConfig.NAVIGATION_MODE, BrowserFieldConfig.NAVIGATION_MODE_POINTER);
BrowserField browserField = new BrowserField(myBrowserFieldConfig);
add(browserField);
browserField.requestContent("http://www.bbc.co.uk");
BrowserFieldListener listener = new BrowserFieldListener() {
public void documentAborted(BrowserField browserField, Document document) {
System.out.println("JERRY: documentAborted");
}
public void documentCreated(BrowserField browserField, ScriptEngine scriptEngine, Document document) {
System.out.println("JERRY: documentCreated");
}
public void documentError(BrowserField browserField, Document document) {
System.out.println("JERRY: documentError");
}
public void documentLoaded(BrowserField browserField, Document document) {
System.out.println("JERRY: documentLoaded");
Node node = document.getFirstChild();
String nodeText = node.getTextContent();
int index = -1;
if (nodeText != null) {
String errorText = "Error requesting content for:";
index = nodeText.indexOf(errorText);
}
Screen screen = browserField.getScreen();
try {
synchronized (Application.getEventLock()) {
if (index == -1) {
System.out.println("JERRY: documentLoaded: no error");
int count = screen.getFieldCount();
if (count > 1) {
screen.deleteRange(0, (count-1));
System.out.println("JERRY: documentLoaded: " + (count-1) + " fields deleted");
} else {
System.out.println("JERRY: documentLoaded: only 1 field so none deleted");
}
} else {
System.out.println("JERRY: documentLoaded: error");
}
}
} catch (final Exception ex) {
System.out.println("example_Screen: documentLoaded: exception caught: " + ex.toString());
}
}
public void documentUnloading(BrowserField browserField, Document document) {
System.out.println("JERRY: documentUnloading");
}
public void downloadProgress(BrowserField browserField, ContentReadEvent event) {
System.out.println("JERRY: downloadProgress");
}
};
browserField.addListener(listener);
// Attach the Error Handler to the BrowserField
BrowserFieldErrorHandler eHandler = new MyBrowserFieldErrorHandler(browserField);
browserField.getConfig().setProperty(BrowserFieldConfig.ERROR_HANDLER, eHandler);
}
}
答案 0 :(得分：2)
BrowserField包含一个addListener()方法，该方法引用BrowserFieldListener实现。
扩展BrowserFieldListener并处理此实施的方法documentError()和documentAborted()中的错误。
然后通过BrowserFieldListener添加将browserField.addListener(browserFieldListener);扩展到您的浏览器字段的类实例的引用。
修改
如果这不起作用，请使用RIM API中的BrowserFieldErrorHandler类。构建自己的错误处理程序并将其实例传递给browserfield配置。
下面是示例代码：
// Create the ErrorHandler class
public class MyBrowserFieldErrorHandler extends BrowserFieldErrorHandler {
public void displayContentError(String url, String errorMessage) {
String error = "Error: (url=" + url + "): " + t.getMessage();
Dialog.ask(Dialog.D_OK, error);
logMessage(“BrowserFieldError: “ + error );
}
public void displayContentError(String url, InputConnection connection, Throwable t) {
displayContentError(url, t.getMessage());
}
public void requestContentError(BrowserFieldRequest request, Throwable t){
displayContentError(request.getURL(), t.getMessage());
}
}
// Attach the Error Handler to the BrowserField
BrowserFieldErrorHandler eHandler = new MyBrowserFieldErrorHandler();
browserField.getConfig().setProperty(BrowserFieldConfig.ERROR_HANDLER,eHandler);
我从DevCon2010的BrowserField功能演示中获取此示例代码。你可以在这里得到它：http://dev.tuyennguyen.ca/wp-content/uploads/2011/02/DEV49.pdf