.h文件中
    @property(strong ,nonitomic) uiwebview * webview;
    .m文件中
    -(void)viewdidload
    {
    self.webview = [[uiwebview alloc]initwithformat:cgrectmake(0,0,320,480)];
    [self.view addsubview:self.webview];
    nsurlrequeast * request = [nsurlrequest requestwithurl:[nsurl urlwit]];
    //運行一下，百度頁面就出來了
    [self.webview loadrequest:request];
    }