UIButton无法显示特定删除图标，其他图片正常问题咨询

Hey there! Let’s figure out why that delete icon isn’t showing up in your UIButton, even when other images load just fine. First, we’ll check if the image itself is the issue, then rule out other common pitfalls.

• Verify format & compatibility: Make sure the delete icon uses an iOS-supported format (PNG, JPG, or PDF for vector assets). If it’s a PDF, double-check that you’ve enabled "Preserve Vector Data" in the Asset Catalog, and that it’s sized appropriately for different screen resolutions. Tiny icons might get compressed to invisibility if your button has a fixed size.
• Test the image in a simple UIImageView: Drop the same icon into a plain UIImageView. If it doesn’t show up there either, the file is likely corrupted or wasn’t imported correctly. Try re-importing the image, or open it in Preview to confirm it displays properly.
• Check Asset Catalog settings: If you’re using Assets.xcassets, compare the "Render As" setting of the delete icon to your working images. For example:
  • If other images use Original Image but this one is set to Template Image without a defined tintColor, it might appear transparent (since template images default to the button’s tint color, which could match the background).
  • If other images are template-based but this one is original, its color might blend perfectly with the button’s background, making it invisible.

• Double-check image assignment method: Did you use setImage(_:for:) (for foreground icons) or setBackgroundImage(_:for:) (for background images)? Using the wrong method could lead to the icon being covered by the button’s background color or content. Also, check if contentEdgeInsets or imageEdgeInsets are pushing the icon outside the button’s bounds—try resetting these to default values to test.
• Inspect tintColor for template images: If your delete icon is a template asset, the button’s tintColor needs contrast with its background. If the tint color matches the button’s background (e.g., both white), the icon will be impossible to see.
• Confirm state-specific settings: Did you only set the icon for the .normal state, but your button is currently in .highlighted or .selected mode? Ensure the icon is set for all relevant states, or let other states inherit the .normal state’s image.

Add this to your code to confirm if the image is even loading correctly:

// Replace "DeleteIcon" with your actual image name
if let deleteImage = UIImage(named: "DeleteIcon") {
    print("Delete image loaded successfully! Size: \(deleteImage.size)")
} else {
    print("Failed to load delete image—check the file name or target membership!")
}

If you see the "Failed to load..." message, the image name is misspelled, or the file isn’t included in your target (make sure the "Target Membership" box is checked for your app target in the image’s file inspector).

内容的提问来源于stack exchange，提问作者user1079052