加载webview应用程序时在顶部显示进度条 [英] Show a progressbar on top while loading webview app

问题描述

我正在尝试在应用程序的顶部显示进度条，例如谷歌浏览器用于Android加载网站时显示加载栏。

I'm trying to show a progressbar on top top the app like google chrome for android shows loading bar while loading a website.

我想显示此进度当用户点击webview应用程序的任何内部链接时...就像谷歌浏览器显示一样。

I want to show this progress bar when user clicks on any internal links of the webview app...just like google chrome shows.

这是我尝试过的，这段代码不起作用，app即使它没有启动也会停止工作。

Here is what I've tried, this code not working, app stops working even it doesn't start.

public class MainActivity extends AppCompatActivity {

    private WebView mWebView;
    private ProgressBar progressBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().setBackgroundDrawable(null);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        progressBar.setMax(100);
        setContentView(R.layout.activity_main);

        mWebView = (WebView) findViewById(R.id.main_webview);
        mWebView.setWebViewClient(new WebViewClient() {

            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                super.onPageStarted(view, url, favicon);
                progressBar.setVisibility(View.VISIBLE);
                progressBar.setProgress(0);
            }

            @Override
            public void onPageFinished(WebView view, String url) {
                super.onPageFinished(view, url);
                progressBar.setVisibility(View.GONE);
                progressBar.setProgress(100);
                if (mWebView.getProgress() == 100) {

                    // show webview
                    mWebView.setVisibility(View.VISIBLE);
                    // hide splash
                    findViewById(R.id.splash_screen).setVisibility(View.GONE);
                }
            }

            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {

                if (Uri.parse(url).getHost().contains("www.example.com")) {
                    return false;
                }

                Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
                view.getContext().startActivity(intent);
                return true;

            }

            public void onReceivedError(WebView view, int errorCode,
                                        String description, String failingUrl) {
                view.loadUrl("file:///android_asset/offline.html");
            }

        });

        mWebView.loadUrl("http://www.example.com/?m=1");
    }

}

主要活动：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/splash_screen"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@mipmap/splash_logo"
        android:visibility="visible" />

    <WebView
        android:id="@+id/main_webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="gone" />
    <ProgressBar
        android:id="@+id/progressBar"
        android:minHeight="2dip"
        android:maxHeight="2dip"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        style="@android:style/Widget.ProgressBar.Horizontal" />
</RelativeLayout>

推荐答案

您创建MyWebChromeClient

You create MyWebChromeClient

public class MyWebChromeClient extends WebChromeClient {
private ProgressListener mListener;

public MyWebChromeClient(ProgressListener listener) {
    mListener = listener;
}

@Override
public void onProgressChanged(WebView view, int newProgress) {
    mListener.onUpdateProgress(newProgress);
    super.onProgressChanged(view, newProgress);
}

public interface ProgressListener {
    public void onUpdateProgress(int progressValue);
}
}

您的MainActivity中的

in Your MainActivity

public class MainActivity extends AppCompatActivity implements MyWebChromeClient.ProgressListener{
private WebView mWebView;
private ProgressBar mProgressBar;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mWebView = (WebView) findViewById(R.id.webView);
    WebSettings webSettings = mWebView.getSettings();
    webSettings.setJavaScriptEnabled(true);

    // add progress bar
    mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
    mWebView.setWebChromeClient(new MyWebChromeClient(this));
    mWebView.setWebViewClient(new WebViewClient() {

        public boolean shouldOverrideUrlLoading(WebView view, String url) {

            view.loadUrl(url);


            return true;
        }

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view, url, favicon);
            mProgressBar.setVisibility(View.VISIBLE);
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);
            mProgressBar.setVisibility(View.GONE);

        }


    });


}


@Override
public void onUpdateProgress(int progressValue) {
    mProgressBar.setProgress(progressValue);
    if (progressValue == 100) {
        mProgressBar.setVisibility(View.INVISIBLE);
    }
}
}

in activity_main.xml

in activity_main.xml

<RelativeLayout
    android:id="@+id/relative_web_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ProgressBar
        android:id="@+id/progressBar"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="fill_parent"
        android:layout_height="@dimen/progress_bar_height"
        android:progressDrawable="@drawable/bg_progress_bar_webview" />

    <WebView
        android:id="@+id/webView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/progressBar" />
</RelativeLayout>

in drawable create bg_progress_bar_webview.xml

in drawable create bg_progress_bar_webview.xml

 <?xml version="1.0" encoding="utf-8"?>
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

<item
    android:id="@android:id/background"
    android:drawable="@android:color/transparent"/>
<item android:id="@android:id/secondaryProgress">
    <scale
        android:drawable="@color/progress_bar_second"
        android:scaleWidth="100%" />
</item>
<item android:id="@android:id/progress">
    <scale
        android:drawable="@color/progress_bar_runing"
        android:scaleWidth="100%" />
</item>

</layer-list>

希望！它可以帮助你

这篇关于加载webview应用程序时在顶部显示进度条的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！