Android - Webview Progressbar

Question

我在webview上面添加了进度条.每当我点击链接时,我只是将进度条显示为可见.

我想在webview上有进度条覆盖,我想显示进度条的百分比.我知道css,但我不知道如何改变android中进度条的位置

<?xml version="1.0" encoding="utf-8"?>
<WebView  xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/webview01"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
/> 

MainActivity.java

public class MainActivity extends Activity {

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

    web = (WebView) findViewById(R.id.webview01);
 // request the progress-bar feature for the activity
    getWindow().requestFeature(Window.FEATURE_PROGRESS);

    // set a webChromeClient to track progress    
    web.setWebChromeClient(new WebChromeClient()
    {
        public void onProgressChanged(WebView view, int progress)
        {
            // update the progressBar
            MainActivity.this.setProgress(progress * 100);
        }
    });


    web.getSettings().setJavaScriptEnabled(true);
    web.loadUrl("url");

}

// To handle "Back" key press event for WebView to go back to previous screen.
@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
    if ((keyCode == KeyEvent.KEYCODE_BACK) && web.canGoBack()) {
        web.goBack();
        return true;
    }
    return super.onKeyDown(keyCode, event);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

要显示进度条百分比,是否需要修改此代码？或者我可以从此代码扩展功能吗？

Answer 1

要显示"页面加载"进度条,请使用以下命令:

在onCreate()中:

// request the progress-bar feature for the activity
getWindow().requestFeature(Window.FEATURE_PROGRESS);

// set a webChromeClient to track progress    
myWebView.setWebChromeClient(new WebChromeClient()
{
 public void onProgressChanged(WebView view, int progress)
 {
   // update the progressBar
   MyActivity.this.setProgress(progress * 100);
 }
});

这将显示在屏幕顶部使用内置样式,就像内置浏览器一样.

如果您希望显示和更新自己的ProgressBar,过程类似,请获取进度条的句柄:

ProgressBar myProgress = (ProgressBar)findViewById(R.id.progressBar1);

...并在onProgressChanged()函数中,使用:

myProgress.setProgress(progress * 100);

而不是MyActivity.this.setProgress().

此外,如果要让ProgressBar出现在WebView前面,则无法使用LinearLayout.使用具有centerInParent ="true"的RelativeLayout,并在布局中列出WebView之后的ProgressBar.