Question

我想在我的项目中实现一个搜索栏，javascript代码是：

       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();
        }
        });

javascript代码为：

 polyhedronGenerator.radius=100
 polyhedronGenerator.Redraw(2)

多面体的半径应该通过搜索条的移动来改变。

我得到了这样的错误：

08-08 11：18：36.114 26557-26557 / com.example.jzhu26.testui E / InputEventReceiver：异常调度输入事件。 08-08 11：18：36.114 26557-26557 / com.example.jzhu26.testui E / MessageQueue-JNI：MessageQueue回调中的异常：handleReceiveCallback 08-08 11：18：36.116 26557-26557 / com.example.jzhu26.testui E / MessageQueue-JNI：java.lang.NullPointerException：尝试调用虚方法＆＃39; void android.webkit.WebView.loadUrl（java .lang.String）＆＃39;在null对象引用上在com.example.jzhu26.testui.nav_two_hard $ 1.onProgressChanged（nav_two_hard.java:96）在android.widget.SeekBar.onProgressRefresh（SeekBar.java:93）在android.widget.ProgressBar.doRefreshProgress（ProgressBar.java:1303）在android.widget.ProgressBar.refreshProgress（ProgressBar.java:1315）在android.widget.ProgressBar.setProgress（ProgressBar.java:1361）在android.widget.AbsSeekBar.trackTouchEvent（AbsSeekBar.java:666）在android.widget.AbsSeekBar.onTouchEvent（AbsSeekBar.java:579）在android.view.View.dispatchTouchEvent（View.java:9300）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在android.view.ViewGroup.dispatchTransformedTouchEvent（ViewGroup.java:2553）在android.view.ViewGroup.dispatchTouchEvent（ViewGroup.java:2197）在com.android.internal.policy.PhoneWindow $ DecorView.superDispatchTouchEvent（PhoneWindow.java:2403）在com.android.internal.policy.PhoneWindow.superDispatchTouchEvent（PhoneWindow.java:1737）在android.app.Activity.dispatchTouchEvent（Activity.java:2771）在android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent（WindowCallbackWrapper.java:63）在com.android.internal.policy.PhoneWindow $ DecorView.dispatchTouchEvent（PhoneWindow.java:2364）在android.view.View.dispatchPointerEvent（View.java:9520）在android.view.ViewRootImpl $ ViewPostImeInputStage.processPointerEvent（ViewRootImpl.java:4230）在android.view.ViewRootImpl $ ViewPostImeInputStage.onProcess（ViewRootImpl.java:4096）在android.view.ViewRootImpl $ InputStage.deliver（ViewRootImpl.java:3642）在android.view.ViewRootImpl $ InputStage.onDeliverToNext（ViewRootImpl.java:3695）在android.view.ViewRootImpl $ InputStage.forward（ViewRootImpl.java:3661）在android.view.ViewRootImpl $ AsyncInputStage.forward（ViewRootImpl.java:3787）在android.view.ViewRootImpl $ InputStage.apply（ViewRootImpl.java:3669）在android.view.ViewRootImpl $ AsyncInputStage.apply（ViewRootImpl.java:3844）在android.view.ViewRootImpl $ InputStage.deliver（ViewRootImpl.java:3642）在android.view.ViewRootImpl $ InputStage.onDeliverToNext（ViewRootImpl.java:3695）在android.view.ViewRootImpl $ InputStage.forward（ViewRootImpl.java:3661）在android.view.ViewRootImpl $ InputStage.apply（ViewRootImpl.java:3669）在android.view.ViewRootImpl $ InputStage.deliver（ViewRootImpl.java:3642）在android.view.ViewRootImpl.deliverInputEvent（ViewRootImpl.java:5922）在android.view.ViewRootImpl.doProcessInputEvents（ViewRootImpl.java:5896）在android.view.ViewRootImpl.enqueueInputEvent（ViewRootImpl.java:5857）在android.view.ViewRootImpl $ WindowInputEventReceiver.onInputEvent（ViewRootImpl.java:6025）在android.view.InputEventReceiver.dispatchInputEvent（InputEventReceiver.java:185）在... 08-08 11：18：36.117 26557-26557 / com.example.jzhu26.testui D / AndroidRuntime：关闭VM

任何人都可以帮助我吗？谢谢！

Answer 1

您忘记在WebView中实例化了！使用构造函数来制作如下：

WebView myWeb = new WebView(getApplicationContext());

无法在android studio

1 个答案: