(PECL imagick 2.0.0)
Imagick::setIteratorIndex — Set the iterator position
$index
)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。
index
The position to set the iterator to
成功时返回 TRUE。
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();
?>
wilcobeekhuizen at gmail dot com (2011-03-14 10:06:11)
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);
?>