php中UTF8编码页面iconv转码失败

$c = ‘测试•字符传换•五一快乐！’;

echo iconv(‘utf-8′, ‘gbk’,$c);

$c = ‘测试•字符传换•五一快乐！’;

echo iconv(‘utf-8′, ‘gbk//IGNORE’,$c);

<?php
$ch = curl_init();
curl_setopt($ch,CURLOPT_URL,”http://www.111cn.net”);
curl_setopt($ch,CURLOPT_HEADER,1);
curl_exec($ch);
curl_close($ch);
?>

?   /**
 * 指定一个图片URL地址抓取后上传并同时发布一条新微博
 *
 * 对应API：{@link http://open.weibo.com/wiki/2/statuses/upload_url_text statuses/upload_url_text}
 *
 * @param string $status  要发布的微博文本内容，内容不超过140个汉字。
 * @param string $url    图片的URL地址，必须以http开头。
 * @return array
 */
function upload_url_text( $status,  $url )
{
    $params = array();
    $params['status'] = $status;
    $params['url'] = $url;
    return $this->oauth->post( 'statuses/upload_url_text', $params, false);
}

    <?php 
    $var1 = 1; 
    $var2 = 2; 
    function test(){ 
         global $var1,$var2; 
         $var2 = &$var1; 
    } 
    test(); 
    echo $var2; 
    ?> 

function test() {
global $a;
unset($a);
}

$a = 1;
test();
print $a;
?>

$a = 1;
$b = 2;

function Sum()
{
global $a, $b;

$b = $a + $b;
}

Sum();
echo $b;
?>

<?php 
    $var1 = 1; 
    function test(){ 
         unset($GLOBALS['var1']); 
    } 
    test(); 
    echo $var1; 
    ?> 

<?php 
    $var1 = 1; 
    function test(){ 
        global  $var1; 
         unset($var1); 
    } 
    test(); 
    echo $var1; 
    ?> 

<?php
echo $str= '你好,这里是卖咖啡!';
echo '<br />';

echo iconv('GB2312', 'UTF-8', $str);      //将字符串的编码从GB2312转到UTF-8
echo '<br />';

echo iconv_substr($str, 1, 1, 'UTF-8');   //按字符个数截取而非字节
print_r(iconv_get_encoding());            //得到当前页面编码信息

echo iconv_strlen($str, 'UTF-8');         //得到设定编码的字符串长度

//也有这样用的

   $content = iconv("UTF-8","gbk//TRANSLIT",$content);
?>

<?php
function phpcharset($data, $to) {
 if(is_array($data)) {
  foreach($data as $key => $val) {
   $data[$key] = phpcharset($val, $to);
  }
 } else {
  $encode_array = array('ASCII', 'UTF-8', 'GBK', 'GB2312', 'BIG5');
  $encoded = mb_detect_encoding($data, $encode_array);
  $to = strtoupper($to);
  if($encoded != $to) {
   $data = mb_convert_encoding($data, $to, $encoded);
  }
 }
 return $data;
}
?>

function asciitog($brand)
{
 $cha=mb_detect_encoding($brand);
 if($cha=='utf-8')
 {
   $brand2 = iconv($cha,"gb2312",$brand);
 }
 $cha2=mb_detect_encoding($brand2);
 if($cha2!='ascii'){
  $brand=$brand2;
 }
 
 return $brand;
}