仿微信中加载网页时带线行进度条的WebView的实现-摩杜云开发者社区

为了仿微信中加载网页时带进度条的WebView的实现，首先我们来看一下微信中的效果是什么样的：

明确需求之后，我们来开始动手做，首先我们来自定义一个带进度条的WebView,名字为ProgressWebView：

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> /** * @Description:带进度条的WebView * @author */ @SuppressWarnings("deprecation") 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, 10, 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); } } </code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li></ul>

从这个类中可以看出，我们在自定义的WebView中加入了一个水平方向的progressbar，然后为这个progressbar设置progressDrawable,这是一个很关键的地方：

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> Drawable drawable = context.getResources().getDrawable(R.drawable.progress_bar_states); progressbar.setProgressDrawable(drawable);</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>

下面我们来看一下drawable目录下的progress_bar_states.xml是如何写的：

<layer-list>这个标签可能我们不是很熟悉，因为我们一般常用的就是<shape>和<selector>这两个，layer-list是将多个图片或上面两种效果按照顺序层叠起来，layer就像photoshop中的图层一样。
其中有个<clip>标签，是可以用来剪载图片显示，例如，可以通过它来做进度度。你可以选择是从水平或垂直方向剪载。
自定义好ProgressWebView之后，我们只需要在xml布局文件中声明就可以使用了：

接着我们定义一个BaseWebActivity来显示我们自定义的WebView：

然后调用这个Activity即可，例如：

好吧，到这里你应该学会怎么做带线行进度条的WebView了吧！