Imagick::setIteratorIndex()
(PECL imagick 2.0.0)
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
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); ?>