Android WebView的使用方法总结

 android webview的使用方法

  android app打开h5页一般要实现如下需求：

1、打开指定url网页；
2、点击链接可以跳转到下一页，并更新标题；
3、按back键或左箭头可以返回上一页；
4、当webview显示的是第一级url时， 按返回键或左箭头关闭当前界面；
5、webview如何传值给android， 例如使用h5登录成功后返回姓名、token等等字段。
6、支持javascript， 支持显示js对话框。
7、无网络时显示默认布局， 以提高用户体验。
8、避免webview的内存泄漏。

不多说， 看下面代码如何实现上述功能。

参考布局：

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:my="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="@color/activity_main_bg"
  android:orientation="vertical">

  <com.eloancn.borrower.common.widget.titleview
    android:id="@+id/titleview"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    my:titletext="h5" />

  <relativelayout
    android:id="@+id/rl_webviewcontainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <!--在代码中添加webview防止内存泄露隐患-->

    <linearlayout
      android:id="@+id/neterror_tip"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:gravity="center_horizontal"
      android:visibility="gone">

      <imageview
        android:layout_margintop="110dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/not_found" />

    </linearlayout>

  </relativelayout>
</linearlayout>

示例代码：

public class commonwebviewactivity extends activity { 
  private webview mwebview; 
  private titleview mtitleview; 
  private relativelayout mwebviewcontainer; 
  private string title; 
  private string url; 
  private linearlayout neterrorlayout; 
  private int mflag;  //来源 
 
  public static final int flag_signature = 1; 
 
  @override 
  protected void oncreate(bundle savedinstancestate) { 
    super.oncreate(savedinstancestate); 
    setcontentview(r.layout.activity_common_webview_main); 
    initdata(); 
    initview(); 
    setdata(); 
  } 
 
  @override 
  protected void ondestroy() { 
    super.ondestroy(); 
    mwebview.setwebviewclient(null); 
    mwebview.setwebchromeclient(null); 
    mwebviewcontainer.removeview(mwebview); 
    mwebview.removeallviews(); 
    mwebview.destroy(); 
  } 
 
  private void initdata() { 
    url = getintent().getstringextra("url"); 
    title = getintent().getstringextra("title"); 
    mflag = getintent().getintextra("flag", 0); 
  } 
 
  private void initview() { 
    mtitleview = (titleview) findviewbyid(r.id.titleview); 
    mwebviewcontainer = (relativelayout) findviewbyid(r.id.rl_webviewcontainer); 
    neterrorlayout = (linearlayout) findviewbyid(r.id.neterror_tip); 
    mwebview = new webview(getapplicationcontext()); 
    linearlayout.layoutparams layoutparams = new linearlayout.layoutparams( 
        linearlayout.layoutparams.match_parent, linearlayout.layoutparams.match_parent); 
    mwebviewcontainer.addview(mwebview, layoutparams); 
 
    websettings websettings = mwebview.getsettings(); 
    //设置webview属性，能够执行javascript脚本 
    websettings.setjavascriptenabled(true); 
    //设置可以访问文件 
    websettings.setallowfileaccess(true); 
    //设置支持缩放 
    websettings.setbuiltinzoomcontrols(false); 
    //允许js弹出窗口 
    websettings.setjavascriptcanopenwindowsautomatically(true); 
 
    mtitleview.setleftbtnclicklistener(new titleview.onbtnclicklistener() { 
      @override 
      public void onclick(view v) { 
        if (mwebview.cangoback()) { 
          mwebview.goback(); 
        } else { 
          finish(); 
        } 
      } 
    }); 
  } 
 
  @override 
  public boolean onkeydown(int keycode, keyevent event) { 
    if (keycode == keyevent.keycode_back) { 
      if (mwebview.cangoback()) { 
        mwebview.goback(); 
        return true; 
      } 
    } 
    return super.onkeydown(keycode, event); 
  } 
 
  private void setdata() { 
    mtitleview.settitle(title); 
    mwebview.loadurl(url); 
 
    mwebview.setwebchromeclient(new webchromeclient(){ 
      @override 
      public boolean onjsalert(webview view, string url, final string message, final jsresult result) { 
        //注意，webview默认不会显示javascript的alert，需要android实现。 
        runonuithread(new runnable() { 
          @override 
          public void run() { 
            //自定义美观的dialog，仅仅是为了显示message 
            customdialog.builder builder = new customdialog.builder(commonwebviewactivity.this); 
            builder.settitle("提示"); 
            builder.setmessage(message); 
            builder.setsingle("知道了", new dialoginterface.onclicklistener() { 
              @override 
              public void onclick(dialoginterface dialoginterface, int i) { 
                dialoginterface.dismiss(); 
              } 
            }); 
            builder.create().show(); 
          } 
        }); 
        result.confirm();//这里必须调用，否则页面会阻塞造成假死 
        return true; 
      } 
 
      @override 
      public void onreceivedtitle(final webview view, final string title) { 
        super.onreceivedtitle(view, title); 
        if (flag_signature == mflag) { 
          runonuithread(new runnable() { 
            @override 
            public void run() { 
              mtitleview.settitle(title); 
            } 
          }); 
        } 
      } 
    }); 
    mwebview.setwebviewclient(new webviewclient() { 
      @override 
      public webresourceresponse shouldinterceptrequest(webview view, webresourcerequest request) { 
        if (flag_signature == mflag) { 
          log.d("brycegao", "shouldinterceptrequest url:" + request.geturl().tostring()); 
          if (request.geturl().tostring().contains("wxd://getimage?tenderid=")) { 
            //可以通过url传值给android， 即在url里放置想要的参数 
            runonuithread(new runnable() { 
              @override 
              public void run() { 
                setresult(result_ok); 
                finish(); 
              } 
            }); 
          } 
 
        } 
        return super.shouldinterceptrequest(view, request); 
      } 
 
      @override 
      public boolean shouldoverrideurlloading(webview view, webresourcerequest request) { 
        mwebview.loadurl(url); 
        return true; 
      } 
 
      @override 
      public void onreceivederror(webview view, webresourcerequest request, webresourceerror error) { 
        super.onreceivederror(view, request, error); 
 
        if (flag_signature == mflag 
            && request.geturl().tostring().contains("wxd://getimage?tenderid=")) { 
          //do nothing 
          mwebview.setvisibility(view.gone); //优化体验，避免显示错误信息 
        } else { 
          //加载失败 
          neterrorlayout.setvisibility(view.visible); 
          mwebview.setvisibility(view.gone); 
        } 
      } 
    }); 
 
    neterrorlayout.setonclicklistener(new view.onclicklistener() { 
      @override 
      public void onclick(view view) { 
        mwebview.setvisibility(view.visible); 
        neterrorlayout.setvisibility(view.gone); 
        mwebview.loadurl(url); 
      } 
    }); 
  } 
} 

以上就是android webview的使用方法详解，大家如果有疑问可以留言讨论，或者到本站社区交流，感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！