Java WebView.canGoBack方法代码示例

import android.webkit.WebView; //导入方法依赖的package包/类
/**
 * Report an error to the host application. These errors are unrecoverable (i.e. the main resource is unavailable).
 * The errorCode parameter corresponds to one of the ERROR_* constants.
 *
 * @param view          The WebView that is initiating the callback.
 * @param errorCode     The error code corresponding to an ERROR_* value.
 * @param description   A String describing the error.
 * @param failingUrl    The url that failed to load.
 */
@Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
    // Ignore error due to stopLoading().
    if (!isCurrentlyLoading) {
        return;
    }
    LOG.d(TAG, "CordovaWebViewClient.onReceivedError: Error code=%s Description=%s URL=%s", errorCode, description, failingUrl);

    // If this is a "Protocol Not Supported" error, then revert to the previous
    // page. If there was no previous page, then punt. The application's config
    // is likely incorrect (start page set to sms: or something like that)
    if (errorCode == WebViewClient.ERROR_UNSUPPORTED_SCHEME) {
        parentEngine.client.clearLoadTimeoutTimer();

        if (view.canGoBack()) {
            view.goBack();
            return;
        } else {
            super.onReceivedError(view, errorCode, description, failingUrl);
        }
    }
    parentEngine.client.onReceivedError(errorCode, description, failingUrl);
}
 

import android.webkit.WebView; //导入方法依赖的package包/类
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
	if(event.getAction() == KeyEvent.ACTION_DOWN){
		switch(keyCode)
		{
		case KeyEvent.KEYCODE_BACK:
			WebView webviewHelp = (WebView)findViewById(R.id.webview_help);
			if(webviewHelp.canGoBack() == true){
				webviewHelp.goBack();
			}else{
				finish();
			}
			return true;
		}

	}
	return super.onKeyDown(keyCode, event);
}
 

import android.webkit.WebView; //导入方法依赖的package包/类
@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
  if (keyCode == KeyEvent.KEYCODE_BACK)
  {
    WebView webView = getAUTWebView();
    if (webView.canGoBack())
    {
      webView.goBack();
      return false;
    }
  }
  return super.onKeyDown(keyCode, event);
}
 

import android.webkit.WebView; //导入方法依赖的package包/类
@Override
public void onBackPressed() {
    WebView myWebView = (WebView) findViewById(R.id.webview);
    if (myWebView.canGoBack() && mWebViewClient.allowBack()) {
        myWebView.goBack();
    } else {
        super.onBackPressed();
    }
}
 

import android.webkit.WebView; //导入方法依赖的package包/类
public boolean canGoBack() {
    WebView view = null;
    if (this.getView() != null && (view = this.getView().getWebView()) != null) {
        return view.canGoBack();
    }

    return false;
}
 

import android.webkit.WebView; //导入方法依赖的package包/类
public boolean canGoForward() {
    WebView view = null;
    if (this.getView() != null && (view = this.getView().getWebView()) != null) {
        return view.canGoBack();
    }

    return false;
}
 

import android.webkit.WebView; //导入方法依赖的package包/类
/**
 * Report an error to the host application. These errors are unrecoverable (i.e. the main resource is unavailable).
 * The errorCode parameter corresponds to one of the ERROR_* constants.
 *
 * @param view          The WebView that is initiating the callback.
 * @param errorCode     The error code corresponding to an ERROR_* value.
 * @param description   A String describing the error.
 * @param failingUrl    The url that failed to load.
 */
@Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
    // Ignore error due to stopLoading().
    if (!isCurrentlyLoading) {
        return;
    }
    LOG.d(TAG, "CordovaWebViewClient.onReceivedError: Error code=%s Description=%s URL=%s", errorCode, description, failingUrl);

    // Clear timeout flag
    this.appView.loadUrlTimeout++;

    // If this is a "Protocol Not Supported" error, then revert to the previous
    // page. If there was no previous page, then punt. The application's config
    // is likely incorrect (start page set to sms: or something like that)
    if (errorCode == WebViewClient.ERROR_UNSUPPORTED_SCHEME) {
        if (view.canGoBack()) {
            view.goBack();
            return;
        } else {
            super.onReceivedError(view, errorCode, description, failingUrl);
        }
    }

    // Handle other errors by passing them to the webview in JS
    JSONObject data = new JSONObject();
    try {
        data.put("errorCode", errorCode);
        data.put("description", description);
        data.put("url", failingUrl);
    } catch (JSONException e) {
        e.printStackTrace();
    }
    this.appView.postMessage("onReceivedError", data);
}
 

import android.webkit.WebView; //导入方法依赖的package包/类
@Override
public void onBackPressed() {
    WebView webview = (WebView) findViewById(R.id.webview);
    if (webview.canGoBack()) {
        webview.goBack();
    } else {
        finish();
    }
}