android控件之WebView控件缩小

package com.weizhu.lan.view;

import com.weizhu.lan.util.myprogressdialog;

import android.app.activity;
import android.app.alertdialog;
import android.content.context;
import android.content.intent;
import android.net.connectivitymanager;
import android.os.asynctask;
import android.os.bundle;
import android.os.handler;
import android.view.keyevent;
import android.view.window;
import android.webkit.webchromeclient;
import android.webkit.webview;
import android.widget.progressbar;

public class helpcenter extends activity {

    //50766649
    private string urlhelp = "//www.jb51.net",
                    userid = "userid=";
    private string yqhid;
    private webview web;
    private handler hand;
    private progressbar pb;
    private myasynctask myasy;
    @override
    protected void oncreate(bundle savedinstancestate) {

        super.oncreate(savedinstancestate);
        requestwindowfeature(window.feature_no_title);
        setcontentview(r.layout.help_webview);

        yqhid = getintent().getstringextra("yqhid");

        web = (webview) findviewbyid(r.id.help_webview1);
        web.getsettings().setbuiltinzoomcontrols(true); //可放大、缩小
        myasy = new myasynctask();
        final string str = urlhelp;
            myasy.execute(str);

    }
    class myasynctask extends asynctask<string, string, void>{

        @override
        protected void doinbackground(string... params) {
            web.loadurl(params[0]);
            web.setwebchromeclient(new webchromeclient(){
                @override
                public void onprogresschanged(webview view, int newprogress) {
                    super.onprogresschanged(view, newprogress);
                    pb.setprogress(newprogress); //它自己会处置进度条
                }
            });
            return null;
        }
        @override
        protected void onpostexecute(void result) {

        }
        @override
        protected void onpreexecute() {
            pb = (progressbar) findviewbyid(r.id.help_progressbar2);
            pb.setprogress(0);
        }
    }
}