Question

我创建了一个自定义的UITableViewCell，它在我的视图控制器中以编程方式添加。自定义单元格包含一个按钮。问题是我无法实现按钮在所有设备上居中。如果它是5s模拟器，我使用self.frame.width作为按钮框架的x坐标，那么它是居中的 - 但不是6或6s，但是如果我使用super.frame.width x-coord，然后以6模拟器为中心。有谁知道如何让它集中在所有设备屏幕上？这是我的自定义按钮的代码，我只是将它作为UITableViewCell返回到我的viewcontroller中的tableView委托......

import Foundation
import UIKit

public class ButtonCell: UITableViewCell {

    //Custom button to be added to the last cell to submit
    let buttonImage = UIImage(named: "add_pub_button") as UIImage?
    let button = UIButton(type: UIButtonType.Custom) as UIButton

    /**
     Creates the ButtonCell

     - parameter style:           A constant indicating a cell style. See UITableViewCellStyle for descriptions of these constants.
     - parameter reuseIdentifier: A string used to identify the cell object if it is to be reused for drawing multiple rows of a table view. Pass nil if the cell object is not to be reused. You should use the same reuse identifier for all cells of the same form.

     - returns: An initialized TextInputCell object or nil if the object could not be created.
     */
    override public init(style: UITableViewCellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        setup()
    }

    private func setup() {

        //Overhangs the view slightly to avoid invalid constraints.
        self.clipsToBounds = true
        self.backgroundView = nil
        self.backgroundColor = nil
        self.tintColor = nil
        self.selectionStyle = .None

        button.frame = CGRectMake((self.frame.width - 134)/2, 0, 134, 44)
        button.tintColor = nil
        button.backgroundColor = nil
        button.setImage(buttonImage, forState: .Normal)

        self.contentView.addSubview(button)
    }

    /**
     Needed for initialization from a storyboard.
     - parameter aDecoder: An unarchiver object.
     - returns: An initialized ButtonCell object or nil if the object could not be created.
     */
    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setup()
    }
}

Answer 1

我不会使用这个框架。我会用constraints。您可以使用以下方法轻松创建一个水平居中的约束：

button.translatesAutoresizingMaskIntoConstraints = false
let centerX = NSLayoutConstraint(item: button, attribute: .CenterX, relatedBy: .Equal, toItem: self, attribute: .CenterX, multiplier: 1, constant: 0)
self.addConstraint(centerX)

Answer 2

只需在SyntaxError: /Users/KOSUKE/workspace/score_share/app/models/user.rb:6: syntax error, unexpected ':', expecting keyword_end format: { with: VALID_EMAIL_REGEX } ^ /Users/KOSUKE/workspace/score_share/app/models/user.rb:7: syntax error, unexpected ':', expecting keyword_end uniqueness: { case_sensitive: false } ^ from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:457:in `load' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:457:in `block in load_file' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:647:in `new_constants_in' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:456:in `load_file' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:354:in `require_or_load' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:494:in `load_missing_constant' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:184:in `const_missing' from (irb):1 from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/railties-4.2.2/lib/rails/commands/console.rb:110:in `start' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/railties-4.2.2/lib/rails/commands/console.rb:9:in `start' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/railties-4.2.2/lib/rails/commands/commands_tasks.rb:68:in `console' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/railties-4.2.2/lib/rails/commands/commands_tasks.rb:39:in `run_command!' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/railties-4.2.2/lib/rails/commands.rb:17:in `<top (required)>' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:274:in `require' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:274:in `block in require' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:240:in `load_dependency' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:274:in `require' from /Users/KOSUKE/workspace/score_share/bin/rails:9:in `<top (required)>' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:268:in `load' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:268:in `block in load' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:240:in `load_dependency' from /Users/KOSUKE/.rvm/gems/ruby-2.2.1/gems/activesupport-4.2.2/lib/active_support/dependencies.rb:268:in `load' from /Users/KOSUKE/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require' from /Users/KOSUKE/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require' from -e:1:in `<main>'2.2.1 :002 >方法

中设置与帧相关的操作

例如，

layoutSubviews

UIButton无法集中在UITableViewCell - Swift中的所有设备上

2 个答案: