Android：如何在将数据加载到 WebView 时显示进度条？

Posted 2023-03-25

【中文标题】Android：如何在将数据加载到 WebView 时显示进度条？

【英文标题】：Android: How can i show progress bar while loading data into WebView?

【发布时间】：2012-03-11 15:00:40

【问题描述】：

如何在将数据加载到我的 webview 时显示进度条？ 我的代码：

public void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);

    this.requestWindowFeature(Window.FEATURE_PROGRESS);
    getWindow().setFeatureInt( Window.FEATURE_PROGRESS, Window.PROGRESS_VISIBILITY_ON); 
    this.setProgressBarVisibility(true);
    setContentView(R.layout.layout_article);
    WebView webview = (WebView) findViewById(R.id.webView);
    final Activity activity = this;
    webview.setWebChromeClient(new WebChromeClient() 
        public void onProgressChanged(WebView view, int progress) 
            activity.setProgress(progress * 100);
        
    );

    webView.loadUrl("http://google.com");

【问题讨论】：

您需要将上传移至单独的线程，以释放主 UI 线程的处理。您还必须决定是显示微调器还是显示进度条。

最好的方法是 Paresh 建议的，但您必须使用 WebViewClient ，使用此技术您不必查看从服务器获取了多少数据。跨度>

希望以下链接对您有所帮助：***.com/questions/9171510/…

android WebView progress bar的可能重复

【参考方案1】：

在调用 loadData() 函数之前，只需尝试显示 ProgressDialog 或将 ProgressBar 放入布局中。

在 WebViewClient 中，只需关闭（）progressDialog 或使 ProgressBar 不可见。

例如：

// when finish loading page
public void onPageFinished(WebView view, String url) 
       if(mProgress.isShowing()) 
             mProgress.dismiss();
       

仅供参考，仅在您完成 Web 客户端设置后调用 loadData() 或 loadURL()。

查看此示例：Load WebView with ProgressDialog

【讨论】：

WebChromeClient class 没有onPageFinished() method，而是在WebViewClient中

你还是写了WebClient它是WebViewClientdeveloper.android.com/reference/android/webkit/…, java.lang.String)

【参考方案2】：

请尝试以下代码，

ProgressDialog progDailog = ProgressDialog.show( context,"Process ", "Loading Data...",true,true);

new Thread ( new Runnable()

     public void run()
     
      // your data loading code goes here
     
).start();

 Handler progressHandler = new Handler() 
 

     public void handleMessage(Message msg1) 
     

         progDailog.dismiss();
         
 

【参考方案3】：

public class MainActivity extends AppCompatActivity 

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

        final ProgressBar progress = (ProgressBar) findViewById(R.id.progress);

        WebView webView = (WebView) findViewById(R.id.webview);
        webView.getSettings().setjavascriptEnabled(true);
        webView.setWebViewClient(new WebViewClient() 
            @Override
            public boolean shouldOverrideUrlLoading(final WebView view, final String url) 
                return false;
            

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

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

        webView.loadUrl("http://google.com");
    

还有R.layout.activity_main:

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

    <WebView
        android:id="@+id/webview"
        android:layout_
        android:layout_ />

    <ProgressBar
        android:id="@+id/progress"
        android:layout_
        android:layout_
        android:visibility="gone"
        android:layout_centerInParent="true"/>
</RelativeLayout>

【参考方案4】：

首先制作自定义 webview 类并像这样在 xml 上使用它，

 <com.app.ui.views.CustomWebView
        android:id="@+id/webView"
        android:layout_
        android:layout_
        >

    </com.app.ui.views.CustomWebView>

确保，高度不应该是固定的，应该是“wrap_content”

现在像这样制作自定义 webview 类，

 public class CustomWebView extends WebView 

    private ProgressBar progressBar;
    private Context context;
    private LinearLayout loaderLayout;

    public CustomWebView(Context context) 
    super(context);

    this.context = context;
    initProgressBar();

    loadUrlWithData();



public CustomWebView(Context context, AttributeSet attrs) 
    super(context, attrs);

    this.context = context;
    initProgressBar();



public CustomWebView(Context context, AttributeSet attrs, int defStyle) 
    super(context, attrs, defStyle);

    this.context = context;

    initProgressBar();



private void initProgressBar() 
    progressBar = new ProgressBar(context);
    progressBar.setIndeterminate(false);



private void setLoading(boolean isLoading) 

  if (isLoading) 

   progressBar.setVisibility(View.VISIBLE);

   loaderLayout = new LinearLayout(context);
   loaderLayout.setGravity(Gravity.CENTER);
   loaderLayout.setOrientation(LinearLayout.HORIZONTAL);

    LinearLayout.LayoutParams parentLayoutParams = new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.MATCH_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT);
        loaderLayout.setLayoutParams(parentLayoutParams);

        LinearLayout.LayoutParams progressBarLayoutParams = new 
        LinearLayout.LayoutParams(75, 75);
        progressBar.setLayoutParams(progressBarLayoutParams);

        if (progressBar.getParent() != null) 
            ((ViewGroup) progressBar.getParent()).removeView(progressBar);
        
        loaderLayout.addView(progressBar);

        // add this loaderLayout to your parent view in which your webview is added

        else 

           progressBar.setVisibility(View.GONE);
        

  

  private void loadUrlWithData()
     setLoading(true);
     //Load your html data with url here

  

 //When the content will be loaded, the webview will change it's height
 @Override
protected void onSizeChanged(int w, int h, int ow, int oh) 
    super.onSizeChanged(w, h, ow, oh);

    if (h > 400) 
        setLoading(false);