WordPress主题制作中自定义头部的相关PHP函数解析

function header_textcolor() {
 echo get_header_textcolor();
}
function get_header_image() {
 $url = get_theme_mod( 'header_image', get_theme_support( 'custom-header', 'default-image' ) );
 
 if ( 'remove-header' == $url )
 return false;
 
 if ( is_random_header_image() )
 $url = get_random_header_image();
 
 if ( is_ssl() )
 $url = str_replace( 'http://', 'https://', $url );
 else
 $url = str_replace( 'https://', 'http://', $url );
 
 return esc_url_raw( $url );
}

//判断是否存在该函数，以便兼容老版本
if ( function_exists( 'get_custom_header' ) ) {
//get_custom_header()->width 调用带向 width 属性
$header_image_width = get_custom_header()->width;
//get_custom_header()->height 调用带向 height 属性
$header_image_height = get_custom_header()->height;
} else {//兼容老版本的代码
$header_image_width = HEADER_IMAGE_WIDTH;
$header_image_height = HEADER_IMAGE_HEIGHT;
}

//打开主题自定义顶部支持
add_theme_support( 'custom-header' );
 
$headarg = array(//将设置打包成数组
 'default-image'     => '',
 'random-default'     => false,
 'width'         => 0,
 'height'         => 0,
 'flex-height'      => false,
 'flex-width'       => false,
 'default-text-color'   => '',
 'header-text'      => true,
 'uploads'        => true,
 'wp-head-callback'    => '',
 'admin-head-callback'  => '',
 'admin-preview-callback' => '',
);
//将数组中的设置添加到自定义顶部上
add_theme_support( 'custom-header', $headarg );

//打开主题自定义顶部支持
add_theme_support( 'custom-header' );
 
$headarg = array(//将设置打包成数组
 'default-image'     => '',
 'random-default'     => false,
 'width'         => 0,
 'height'         => 0,
 'flex-height'      => false,
 'flex-width'       => false,
 'default-text-color'   => '',
 'header-text'      => true,
 'uploads'        => true,
 'wp-head-callback'    => '',
 'admin-head-callback'  => '',
 'admin-preview-callback' => '',
);
//将数组中的设置添加到自定义顶部上
add_theme_support( 'custom-header', $headarg );

$args = array(
 'flex-width'  => true,//自适应高度
 'width'     => 980,
 'flex-width'  => true,//自适应宽度
 'height'    => 200,
 'default-image' => get_template_directory_uri() . '/images/header.jpg',
);
add_theme_support( 'custom-header', $args );

<img 
  src="<?php header_image(); ?>" 
  height="<?php echo get_custom_header()->height; ?>" 
  width="<?php echo get_custom_header()->width; ?>" 
  alt="" 
/>