在WebView Android中检测到URL时如何更改活动

Question

I try to change Activity when an URL is detected in webview in my Android app. I get this error:

Unable to start activity ComponentInfo{"xxx"}: android.content.ActivityNotFoundException: No Activity found to handle Intent { act=Open.Tok.Act }

Here is my AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="dk.westsoftdevelopment.elaegen" >

    <uses-sdk
        android:minSdkVersion="16"
        android:targetSdkVersion="17" />

    <!-- To auto-complete the email text field in the login form with the user's emails -->
    <uses-permission android:name="android.permission.GET_ACCOUNTS" />
    <uses-permission android:name="android.permission.READ_PROFILE" />
    <uses-permission android:name="android.permission.READ_CONTACTS" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

    <!-- Using the camera -->
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.RECORD_AUDIO" />
    <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />

    <uses-feature android:name="android.hardware.camera" />
    <uses-feature android:name="android.hardware.camera.autofocus" />


    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="a"
        android:theme="@style/AppTheme"
        >
        <activity android:name=".OpenTokActivity" android:configChanges="orientation|keyboardHidden|screenSize">
            <intent-filter>
                <action android:name="Open.Tok.Act" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".WebViewActivity" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Here is my code for my WebView :

aWebView.setWebViewClient(new WebViewClient(){

    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        return super.shouldOverrideUrlLoading(view, url);
    }

    @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);

        if(url.equals("http://95.85.53.176/nhi/booktid"))
        {
            Log.d(LOGTAG, "GO TO OPENTOK!!!");
            startActivity(new Intent("OpenTokAct"));
        }
        Log.d(LOGTAG,"current URL = " + url);

    }



});

aWebView.loadUrl(mainUrl);

I Have also tried this in the beginning of onCreate() , but it gives me same error...

Intent openStartingPoint = new Intent("Open.Tok.Act");
startActivity(openStartingPoint);

Thank you

Answer 1

Try this,

Intent intent = new Intent(MainActivity.this, Second.class);
startActivity(intent);

Answer 2

When firing an Intent , you have two choices: to make it explicit or implicit .

Right now, you're doing the latter. In order for that to work, your OpenTokActivity 's intent filter will need to be updated accordingly:

<intent-filter>
    <action android:name="Open.Tok.Act" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" /> <!-- optional -->
</intent-filter>`

Why?

• The DEFAULT category is required for the Context.startActivity() method to resolve your activity when its component name is not explicitly specified.
• The BROWSABLE category should be added to activities that can be safely invoked from a browser.

Note that since you're creating the Intent yourself, you don't need the 'browsable' category. If, at some later stage, you would want the website to automatically trigger a redirect that opens the activity in your app, then you'll need to add it back in. Above is all documented here .

However, unless you're going to have more than one activity that can handle the custom action, it is going to be a lot easier to just fire an explicit intent:

startActivity(view.getContext(), OpenTokActivity.class);

You can then remove the whole <intent-filter> ... </intent-filter> part of OpenTokActivity , unless you deliberately added the LAUNCHER category (which will add an entry point for the activity in the top-level launcher).

Answer 3

Different ways of starting activities in android.

First Way : - Explicit

Intent intent = new Intent(this, MainActivity.class);
this.startActivity(intent);

Second Way : - Implicit

startActivity(new Intent("dk.westsoftdevelopment.elaegen.OpenTokActivity"));

Hope it will help you.