Android带进度条的WebView

在加载H5页面的时候，可能由于网络、页面内容复杂度等原因，导致加载过程出现空白，加上进度条可以有效提高用户体验

一、自定义ProgressWebView类

public class ProgressWebView extends WebView {

    private ProgressBar progressbar;

    public ProgressWebView(Context context, AttributeSet attrs) {
        super(context, attrs);
        progressbar = new ProgressBar(context, null,
                android.R.attr.progressBarStyleHorizontal);
        progressbar.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,
                5, 0, 0));
        Drawable drawable = context.getResources().getDrawable(R.drawable.progress_bar_states);
        progressbar.setProgressDrawable(drawable);
        addView(progressbar);
        // setWebViewClient(new WebViewClient(){});
        setWebChromeClient(new WebChromeClient());
        //是否可以缩放
        getSettings().setSupportZoom(true);
        getSettings().setBuiltInZoomControls(true);
    }

    public class WebChromeClient extends android.webkit.WebChromeClient {
        @Override
        public void onProgressChanged(WebView view, int newProgress) {
            if (newProgress == 100) {
                progressbar.setVisibility(GONE);
            } else {
                if (progressbar.getVisibility() == GONE)
                    progressbar.setVisibility(VISIBLE);
                progressbar.setProgress(newProgress);
            }
            super.onProgressChanged(view, newProgress);
        }
    }

    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        LayoutParams lp = (LayoutParams) progressbar.getLayoutParams();
        lp.x = l;
        lp.y = t;
        progressbar.setLayoutParams(lp);
        super.onScrollChanged(l, t, oldl, oldt);
    }
}

二、布局文件标签写成自定义的类，使用和一般WebView一致

最后贴一下drawable下的progress_bar_states

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:id="@android:id/background">
        <shape>
            <corners android:radius="2dp" />
            <gradient
                android:angle="270"
                android:centerColor="#E3E3E3"
                android:endColor="#E6E6E6"
                android:startColor="#C8C8C8" />
        </shape>
    </item>
    <item android:id="@android:id/progress">
        <clip>
            <shape>
                <corners android:radius="2dp" />

                <gradient
                    android:centerColor="#4AEA2F"
                    android:endColor="#31CE15"
                    android:startColor="#5FEC46" />
            </shape>
        </clip>
    </item>
</layer-list>