我们平时在进行安卓开发使用到webview加载网页时,我们不能准确了解网页的加载进度,因此为了提高用户体验,我们在webview中加入进度条显示加载进度。如下是显示效果
布局:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.abc.myapplication.MainActivity"> <ProgressBar android:id="@+id/progressBar" style="@style/crowd_item_progressBar" android:layout_width="match_parent" android:layout_height="3dp" android:background="@drawable/crowd_progressbar_background" /> <WebView android:id="@+id/webview" android:layout_width="wrap_content" android:layout_height="wrap_content"></WebView> </LinearLayout>
进度条背景色:
<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="#2f4eea" android:endColor="#2b15ce" android:startColor="#464cec" /> </shape> </clip> </item> </layer-list>
MainActivity代码:
package com.example.abc.myapplication; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.KeyEvent; import android.webkit.WebChromeClient; import android.webkit.WebResourceRequest; import android.webkit.WebSettings; import android.webkit.WebView; import android.webkit.WebViewClient; import android.widget.ProgressBar; import static android.view.View.GONE; import static android.view.View.VISIBLE; public class MainActivity extends AppCompatActivity { private WebView webView; private ProgressBar progressBar; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); init(); webView.loadUrl("http://www.baidu.com"); } private void init() { webView=findViewById(R.id.webview); progressBar=findViewById(R.id.progressBar); webView.setWebViewClient(new WebViewClient(){ @Override public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) { return super.shouldOverrideUrlLoading(view, request); } }); WebSettings seting=webView.getSettings(); seting.setJavaScriptEnabled(true); webView.setWebChromeClient(new 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 public boolean onKeyDown(int keyCode, KeyEvent event) { if(keyCode==KeyEvent.KEYCODE_BACK) { if(webView.canGoBack()) { webView.goBack(); return true; } else { System.exit(0); } } return super.onKeyDown(keyCode, event); } }