CODEWITHSUNDEEP
javascriptandroid-studioandroid-webview
Jasmin
Jasmin

Reputation: 1

Can't loadUrl javascript in android studio

I want to realize a seekbar in my project,the javascript code is:

       seekBarR.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        int progressChangedValue = 0;
        WebView myWeb;
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            progressChangedValue = progress;

            myWeb.loadUrl("javascript:polyhedronGenerator.radius='+progress+'");
            myWeb.loadUrl("javascript:polyhedronGenerator.Redraw(0)");

        }

        public void onStartTrackingTouch(SeekBar seekBar) {
            // TODO Auto-generated method stub
        }

        public void onStopTrackingTouch(SeekBar seekBar) {
            Toast.makeText(nav_two_hard.this, "Seek bar progress is :" + progressChangedValue,
                    Toast.LENGTH_SHORT).show();
        }
        });

The javascript code is:

 polyhedronGenerator.radius=100
 polyhedronGenerator.Redraw(2)

The radius of a polyhedron should be change by the movement of seekbar.

I got the error like this:

08-08 11:18:36.114 26557-26557/com.example.jzhu26.testui E/InputEventReceiver: Exception dispatching input event. 08-08 11:18:36.114 26557-26557/com.example.jzhu26.testui E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback 08-08 11:18:36.116 26557-26557/com.example.jzhu26.testui E/MessageQueue-JNI: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.webkit.WebView.loadUrl(java.lang.String)' on a null object reference at com.example.jzhu26.testui.nav_two_hard$1.onProgressChanged(nav_two_hard.java:96) at android.widget.SeekBar.onProgressRefresh(SeekBar.java:93) at android.widget.ProgressBar.doRefreshProgress(ProgressBar.java:1303) at android.widget.ProgressBar.refreshProgress(ProgressBar.java:1315) at android.widget.ProgressBar.setProgress(ProgressBar.java:1361) at android.widget.AbsSeekBar.trackTouchEvent(AbsSeekBar.java:666) at android.widget.AbsSeekBar.onTouchEvent(AbsSeekBar.java:579) at android.view.View.dispatchTouchEvent(View.java:9300) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2197) at com.android.internal.policy.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2403) at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1737) at android.app.Activity.dispatchTouchEvent(Activity.java:2771) at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:63) at com.android.internal.policy.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2364) at android.view.View.dispatchPointerEvent(View.java:9520) at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4230) at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4096) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3642) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3695) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3661) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3787) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3669) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3844) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3642) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3695) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3661) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3669) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3642) at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5922) at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5896) at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5857) at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6025) at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185) at a 08-08 11:18:36.117 26557-26557/com.example.jzhu26.testui D/AndroidRuntime: Shutting down VM

Can anyone help me with it? Thanks!

Upvotes: 0

Views: 123

Answers (1)

Logan Rodie
Logan Rodie

Reputation: 693

You forgot to instantiate in your WebView! Use a constructor to make one like this:

WebView myWeb = new WebView(getApplicationContext());

Upvotes: 0

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