android没有意识到progressbar已初始化

时间：2018-09-17 15:12:23

标签： java android xml

所以我正在使用带有加载进度条的webview来做一个应用程序，而我在几个活动中都这样做了，事情就是在一个活动中抛出这个

              E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.examplem16.vics_0.m16, PID: 30491
              java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setVisibility(int)' on a null object reference
                  at com.examplem16.vics_0.m16.ServiciosActivity$MyWebViewClient.onPageStarted(ServiciosActivity.java:183)
                  at xl.b(SourceFile:219)
                  at agX.handleMessage(SourceFile:20)
                  at android.os.Handler.dispatchMessage(Handler.java:102)
                  at android.os.Looper.loop(Looper.java:154)
                  at android.app.ActivityThread.main(ActivityThread.java:6123)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757)

问题似乎是当我想告诉进度栏变为可见时，它无法识别它为已初始化

我检查了一种有效的活动并将其与该活动进行比较，但我似乎不知道出了什么问题

这是一项有效的活动

public class CursosActivity extends AppCompatActivity {

private WebView webView;
private ProgressBar spinner;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_cursos);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);



    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setImageResource(R.drawable.ic_whatsapp_white_48dp);
    fab.setBackgroundTintList(ColorStateList.valueOf(Color
            .parseColor("#4674B7")));
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            try{
                onClickWhatsApp();
            }
            catch(Exception e)
            {

            }
        };
    });


    spinner = (ProgressBar) findViewById(R.id.progressBar1); //initialize
    spinner.getIndeterminateDrawable().setColorFilter(ContextCompat.getColor(this, R.color.colorPrimary), android.graphics.PorterDuff.Mode.SRC_IN);

    String url = "https://mutual16.org/formacion-profesional/";
    webView = (WebView) findViewById(R.id.webViewCursos);
    webView.setWebViewClient(new MyWebViewClient());
    webView.loadUrl(url);
    webView.getSettings().setJavaScriptEnabled(true);
    webView.setScrollBarStyle(View.SCROLLBARS_OUTSIDE_OVERLAY);
    webView.getSettings().setUseWideViewPort(true);
    webView.getSettings().setLoadWithOverviewMode(true);

    webView.setWebViewClient(new MyWebViewClient() {


        @Override
        public void onLoadResource(WebView view, String url) {
            try {
                webView.loadUrl("javascript:(function() { " +
                        "var head = document.getElementsByTagName('header')[0];"
                        + "head.parentNode.removeChild(head);" +
                        "})()");

                webView.loadUrl("javascript:(function() { " +
                        "var head = document.getElementsByTagName('footer')[0];"
                        + "head.parentNode.removeChild(head);" +
                        "})()");
                webView.loadUrl("javascript:(function() { " +
                        "var head = document.getElementsByClassName('ssbp-container')[0];"
                        + "head.parentNode.removeChild(head);" +
                        "})()");
                webView.loadUrl("javascript:(function getStyle(elem, name) {" +
                        "    // J/S Pro Techniques p136" +
                        "    if (elem.style[name]) {" +
                        "        return elem.style[name];" +
                        "    } else if (elem.currentStyle) {" +
                        "        return elem.currentStyle[name];" +
                        "    }" +
                        "    else if (document.defaultView && document.defaultView.getComputedStyle) {" +
                        "        name = name.replace(/([A-Z])/g, \"-$1\");" +
                        "        name = name.toLowerCase();" +
                        "        s = document.defaultView.getComputedStyle(elem, \"\");" +
                        "        return s && s.getPropertyValue(name);" +
                        "    } else {" +
                        "        return null;" +
                        "    }" + "})()");

                webView.loadUrl("javascript:(function() {" +
                        "var element = document.getElementById('page-container')," +
                        "padding = getStyle(element, 'paddingTop'); " +
                        "element.style.paddingTop = parseInt(padding, 0) + 0 + 'px';" + "})()");




            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
        }

        @Override
        public void onPageFinished(WebView web, String url) {
            super.onPageFinished(web, url);
            spinner.setVisibility(View.INVISIBLE);
            setTitle(web.getTitle());

            }


    }
    );
}

@Override
public void onBackPressed() {
    if (webView.canGoBack()) {
        webView.goBack();
    } else {
        super.onBackPressed();
    }
}

private class MyWebViewClient extends WebViewClient {

    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        String urlHost = Uri.parse(url).getHost();
        switch (urlHost) {
            case "mutual16.org":
                return false;
            case "www.mutual16.org":
                return false;
            case "https://mutual16.org":
                return false;
            default:
                Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
                startActivity(intent);
                return true;
        }
    }

    @Override
    public void onPageStarted(WebView webview, String url, Bitmap favicon) {
        super.onPageStarted(webView, url, favicon);
        spinner.setVisibility(View.VISIBLE); //same line with problem in the other activity

    }

    @Override
    public void onPageFinished(WebView view, String url) {

        super.onPageFinished(view, url);
        spinner.setVisibility(View.INVISIBLE);
        setTitle(view.getTitle());

    }

}

public void onClickWhatsApp() {

    try {
        PackageManager packageManager = this.getPackageManager();
        Intent i = new Intent(Intent.ACTION_VIEW);
        String url = "https://api.whatsapp.com/send?phone="+"543512002828" ;
        i.setPackage("com.whatsapp");
        i.setData(Uri.parse(url));
        if (i.resolveActivity(packageManager) != null) {
            this.startActivity(i);
        }
    } catch (Exception e){
        e.printStackTrace();
    }


}


}

，这里是它的xml 

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context=".CursosActivity"
tools:layout_editor_absoluteY="81dp"
tools:showIn="@layout/activity_cursos">

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:background="?attr/colorPrimary"
    android:minHeight="?attr/actionBarSize"
    android:theme="?attr/actionBarTheme">
    <!-- #4674B7 -->

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/facebookm16blanco2"
        android:layout_gravity="center"
        android:id="@+id/toolbar_logo"
        android:contentDescription="@string/content_description_logo_M16"/>


</android.support.v7.widget.Toolbar>

<WebView
    android:id="@+id/webViewCursos"
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/toolbar" />

<ProgressBar
    android:id="@+id/progressBar1"
    style="?android:attr/progressBarStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:visibility="invisible"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

这是无效的活动

public class ServiciosActivity extends AppCompatActivity {

private WebView webView;
private ProgressBar spinner;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_servicios);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);



    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setImageResource(R.drawable.ic_whatsapp_white_48dp);
    fab.setBackgroundTintList(ColorStateList.valueOf(Color
            .parseColor("#4674B7")));
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            try{
                onClickWhatsApp();
            }
            catch(Exception e)
            {

            }
        };
    });


    spinner = (ProgressBar) findViewById(R.id.progressBar1); //initialize


    String url = "https://mutual16.org/servicios/";
    webView = (WebView) findViewById(R.id.webViewServicios);
    webView.setWebViewClient(new MyWebViewClient());
    webView.loadUrl(url);
    webView.getSettings().setJavaScriptEnabled(true);
    webView.setScrollBarStyle(View.SCROLLBARS_OUTSIDE_OVERLAY);
    webView.getSettings().setUseWideViewPort(true);
    webView.getSettings().setLoadWithOverviewMode(true);

    webView.setWebViewClient(new MyWebViewClient() {


        @Override
        public void onLoadResource(WebView view, String url)
        {
            try {
                webView.loadUrl("javascript:(function() { " +
                        "var head = document.getElementsByTagName('header')[0];"
                        + "head.parentNode.removeChild(head);" +
                        "})()");

                webView.loadUrl("javascript:(function() { " +
                        "var head = document.getElementsByTagName('footer')[0];"
                        + "head.parentNode.removeChild(head);" +
                        "})()");
                webView.loadUrl("javascript:(function() { " +
                        "var head = document.getElementsByClassName('ssbp-container')[0];"
                        + "head.parentNode.removeChild(head);" +
                        "})()");
                webView.loadUrl("javascript:(function getStyle(elem, name) {" +
                        "    // J/S Pro Techniques p136" +
                        "    if (elem.style[name]) {" +
                        "        return elem.style[name];" +
                        "    } else if (elem.currentStyle) {" +
                        "        return elem.currentStyle[name];" +
                        "    }" +
                        "    else if (document.defaultView && document.defaultView.getComputedStyle) {" +
                        "        name = name.replace(/([A-Z])/g, \"-$1\");" +
                        "        name = name.toLowerCase();" +
                        "        s = document.defaultView.getComputedStyle(elem, \"\");" +
                        "        return s && s.getPropertyValue(name);" +
                        "    } else {" +
                        "        return null;" +
                        "    }" + "})()");

                webView.loadUrl("javascript:(function() {" +
                                "var element = document.getElementById('page-container')," +
                                "padding = getStyle(element, 'paddingTop'); " +
                                "element.style.paddingTop = parseInt(padding, 0) + 0 + 'px';" +"})()");



            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);
            spinner.setVisibility(View.INVISIBLE);
            setTitle(view.getTitle());

        }


    }
    );
}

@Override
public void onBackPressed() {
    if(webView.canGoBack())
    {
        webView.goBack();
    }
    else
    {
        super.onBackPressed();
    }
}

private class MyWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            String urlHost = Uri.parse(url).getHost();
            switch (urlHost) {
                case "mutual16.org":
                    return false;
                case "www.mutual16.org":
                    return false;
                case "https://mutual16.org":
                    return false;
                default:
                    Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
                    startActivity(intent);
                    return true;
            }
        }

    @Override
    public void onPageStarted(WebView webview, String url, Bitmap favicon) {
        super.onPageStarted(webView, url, favicon);
        spinner.setVisibility(View.VISIBLE); //line 183

    }

    @Override
    public void onPageFinished(WebView view, String url) {

        super.onPageFinished(view, url);
        spinner.setVisibility(View.INVISIBLE);
        setTitle(view.getTitle());

    }

}

public void onClickWhatsApp() {

    try {
        PackageManager packageManager = this.getPackageManager();
        Intent i = new Intent(Intent.ACTION_VIEW);
        String url = "https://api.whatsapp.com/send?phone="+"543512002828" ;
        i.setPackage("com.whatsapp");
        i.setData(Uri.parse(url));
        if (i.resolveActivity(packageManager) != null) {
            this.startActivity(i);
        }
    } catch (Exception e){
        e.printStackTrace();
    }


}






}

，这里是它的xml 

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context=".ServiciosActivity"
tools:showIn="@layout/activity_servicios">

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="?attr/colorPrimary"
    android:theme="?attr/actionBarTheme"

    android:minHeight="?attr/actionBarSize">

    <!-- #4674B7 -->

    <ImageView
        android:id="@+id/toolbar_logo"
        android:contentDescription="@string/content_description_logo_M16"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:src="@drawable/facebookm16blanco2" />


</android.support.v7.widget.Toolbar>

<WebView
    android:id="@+id/webViewServicios"
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/toolbar" />

<ProgressBar
    android:id="@+id/progressBar1"
    style="?android:attr/progressBarStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:visibility="invisible"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

编辑：

按照@TheWanderer的要求添加activity_servicios和activity_cursos xmls

第一个有效的（activity_cursos）

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".CursosActivity">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

</android.support.design.widget.AppBarLayout>

<include layout="@layout/content_cursos" />

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom|end"
    android:layout_margin="@dimen/fab_margin"
    app:srcCompat="@android:drawable/ic_dialog_email" />

这里是无效的（activity_servicios）

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ServiciosActivity">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

</android.support.design.widget.AppBarLayout>

<include layout="@layout/content_servicios" />

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom|end"
    android:layout_margin="@dimen/fab_margin"
    app:srcCompat="@android:drawable/ic_dialog_email" />

1 个答案:

答案 0 :(得分：-1)

最后，我能够查明原因，我在那里有一个layout-v21文件夹和content_servicios xml，那里没有进度条，这是造成问题的原因，只是添加了进度条就可以了

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