Android利用AsyncTask异步类实现网页内容放大缩小
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2024-03-06 09:48:31
本文实例为大家分享了asynctask异步类实现网页内容放大缩小的详细代码,供大家参考,具体内容如下
webactivity.java:
package c...
本文实例为大家分享了asynctask异步类实现网页内容放大缩小的详细代码,供大家参考,具体内容如下
webactivity.java:
package com.supermario.filemanager; import java.io.file; import java.io.fileinputstream; import java.io.filenotfoundexception; import java.io.ioexception; import org.apache.http.protocol.http; import android.app.activity; import android.app.alertdialog; import android.content.dialoginterface; import android.content.dialoginterface.onclicklistener; import android.os.asynctask; import android.os.bundle; import android.view.view; import android.webkit.websettings; import android.webkit.webview; import android.widget.relativelayout; import android.widget.zoomcontrols; public class webactivity extends activity { //网页浏览器 private webview webview; //进度条布局和网页内容主体布局 private relativelayout loadinglayout,weblayout; //放大缩小控制器 private zoomcontrols zoomcontrols; @override protected void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.web); //初始化页面组件 webview = (webview)findviewbyid(r.id.webkit); loadinglayout = (relativelayout)findviewbyid(r.id.loadinglayout); weblayout = (relativelayout)findviewbyid(r.id.weblayout); zoomcontrols = (zoomcontrols)findviewbyid(r.id.zoomcontrols); websettings websettings = webview.getsettings(); //设置可以使用js脚本 websettings.setjavascriptenabled(true); //执行异步进程 new myasynctask().execute(""); } private void reading(){ string filepath = getintent().getstringextra("filepath"); if (filepath != null) { //读取文件 webview.loaddata(readwebdatatostringfrompath(filepath, new filereadoverback() { @override public void filereadover() { } }), "text/html", http.utf_8); } else { new alertdialog.builder(webactivity.this).settitle("出错了").setmessage("获取文件路径出错!").setpositivebutton("返回", new onclicklistener() { @override public void onclick(dialoginterface dialog, int which) { webactivity.this.finish(); } }); } } //将网页数据读取到一个字符串变量中 private string readwebdatatostringfrompath(string path,final filereadoverback filereadoverback){ file file = new file(path); stringbuffer stringbuffer = new stringbuffer(); try { //读取文件内容 fileinputstream inputstream = new fileinputstream(file); byte[] bytes = new byte[1024]; int readcount = 0; while ((readcount = inputstream.read(bytes)) > 0) { stringbuffer.append(new string(bytes, 0, readcount)); } filereadoverback.filereadover(); } catch (filenotfoundexception e) { return "文件不存在!"; } catch (ioexception e) { return "文件读取错误!"; } return stringbuffer.tostring(); } interface filereadoverback{ void filereadover(); } //异步处理类 class myasynctask extends asynctask<string, string, string>{ //首先执行的函数 @override protected void onpreexecute() { super.onpreexecute(); loadinglayout.setvisibility(view.visible); weblayout.setvisibility(view.gone); } //后台执行 @override protected string doinbackground(string... params) { reading(); return null; } @override protected void onpostexecute(string result) { super.onpostexecute(result); //设置载入进度条隐藏 loadinglayout.setvisibility(view.gone); //设置浏览器内容可见 weblayout.setvisibility(view.visible); // 放大按钮 zoomcontrols.setonzoominclicklistener(new view.onclicklistener() { //将网页内容放大 @override public void onclick(view v) { webview.zoomin(); } }); // 缩小按钮 zoomcontrols.setonzoomoutclicklistener(new view.onclicklistener() { //将网页内容缩小 @override public void onclick(view v) { webview.zoomout(); } }); } } }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。
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