Imagick::setIteratorIndex

(PECL imagick 2.0.0)

Imagick::setIteratorIndex — Set the iterator position

说明

Imagick::setIteratorIndex ( int $index ) : bool

Set the iterator to the position in the image list specified with the index parameter. 此方法在Imagick基于ImageMagick 6.2.9以上版本编译时可用。

参数

index: The position to set the iterator to

返回值

成功时返回 TRUE。

范例

Example #1 Using Imagick::setIteratorIndex():

Create images, set and get the iterator index


<?php
$im = new Imagick();
$im->newImage(100, 100, new ImagickPixel("red"));
$im->newImage(100, 100, new ImagickPixel("green"));
$im->newImage(100, 100, new ImagickPixel("blue"));

$im->setIteratorIndex(1);
echo $im->getIteratorIndex();
?>

参见

Imagick::getIteratorIndex() - Gets the index of the current active image
Imagick::getImageIndex() - Gets the index of the current active image
Imagick::setImageIndex() - Set the iterator position

User Contributed Notes

wilcobeekhuizen at gmail dot com 14-Mar-2011 10:06


This function returns true on success but setting the iterator to an invalid index throws an exception instead of returning false:


Fatal error: Uncaught exception 'ImagickException' with message 'Unable to set iterator index'





This can happen when counting images inside a gif file, because the iterator count starts at zero and not one. If you count the number of images in a gif file be sure to use iterator 0 for the first image, like this:





<?php


$image = new Imagick('simple.gif');


$image->setIteratorIndex(0);


?>