嗨，我正在尝试谷歌堆叠柱状图。但我遇到了以下错误，无法解决。错误为"Uncaught TypeError:无法读取null的属性'type'"
这是我的代码
<html>
<head>
<title></title>
</head>
<?php $con=mysql_connect("localhost","root", "innernet") or die("Failed to connect with database!!!!");
mysql_select_db("mobiledb", $con);
$user= $_GET['user'];
//echo $user;
$response["cols"] = array();
// $news = array();
//$news["id"] = "";
//$news["label"] = "ID";
//$news["type"] = "string";
//array_push($response["cols"], $news);
array_push($response["cols"], $news);
$news = array();
//$news["id"] = "";
//$news["label"] = "Q9a";
$news["type"] = "number";
array_push($response["cols"], $news);
$news = array();
//$news["id"] = "";
//$news["label"] = "Q9b";
$news["type"] = "number";
array_push($response["cols"], $news);
// $news = array();
// $news["id"] = "";
//$news["label"] = "ts";
// $news["type"] = "number";
// array_push($response["cols"], $news);
$result = mysql_query("SELECT `Q9a`, `Q9b` FROM goaltest WHERE id='$user'") or die(mysql_error());
if (mysql_num_rows($result) > 0)
{
$response["rows"] = array(); $table = array(); $rows = array();
while ($row = mysql_fetch_array($result))
{
$temp = array();
//$temp[] = array('v' => (string) $row['id']);
$temp[] = array('v' => (int) $row['Q9a']);
$temp[] = array('v' => (int) $row['Q9b']);
//$temp[] = array('v' => (int) $row['ts']);
array_push($response["rows"], array('c' => $temp));
}
//echo json_encode($response);
}
?>
<!--Load the AJAX API -->
<script type="text/javascript" src="http://www.google.com/jsapi"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
google.load("visualization", "1.0", {packages:["imagechart"]});
</script>
<script type='text/javascript'>
google.setOnLoadCallback(drawChart);
function drawChart() {
var response = '<?php echo json_encode($response); ?>'; alert(' hi ' + response);
var obj = eval ("(" + response + ")");
var dataTable = new google.visualization.DataTable(response);
var options = {cht: 'bvs', chs: '300x125', colors:['#4D89F9','#C6D9FD'],
chds:'0,160', chxl:'0:|oranges|apples|pears|bananas|kiwis|'};
var chart = new google.visualization.ImageChart(document.getElementById('bar_div'));
chart.draw(dataTable, options);
}
</script>
<body>
<div id='bar_div'></div>
</body>
</html>
所以请任何人告诉我如何解决这个
<html>
<head>
<title></title>
</head>
<!--Load the AJAX API -->
<script type="text/javascript" src="http://www.google.com/jsapi"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
google.load("visualization", "1.0", {packages:["imagechart"]});
</script>
<script type='text/javascript'>
google.setOnLoadCallback(drawChart);
function drawChart() {
var response = '{"cols":[null,{"type":"number"},{"type":"number"}],"rows":[{"c":[{"v":12},{"v":23}]},{"c":[{"v":37},{"v":55}]}]}'; alert(' hi ' + response);
var obj = eval ("(" + response + ")");
var dataTable = new google.visualization.DataTable(response);
var options = {cht: 'bvs', chs: '300x125', colors:['#4D89F9','#C6D9FD'],
chds:'0,160', chxl:'0:|oranges|apples|pears|bananas|kiwis|'};
var chart = new google.visualization.ImageChart(document.getElementById('bar_div'));
chart.draw(dataTable, options);
}
</script>
<body>
<div id='bar_div'></div>
</body>
</html>
（@asgarden可能已经猜对了。）在您的第一个array_push（…$news）中，$news尚未定义。因此，响应变量中"cols"属性下的第一个数组元素为null。也许你只是想评论一下第一个array_push。