更改UISearchBar中UItextField中圖標的顏色

Question

我試圖自定義搜索控制器中搜索欄的外觀。

設置背景和文本的顏色工作正常，但我只是沒有找到一種方法來改變文本字段中的圖標的顏色，特別是放大鏡和X按鈕。

我發現這個Objective-C代碼應該做我想做的，但我努力把它翻譯斯威夫特：

（編輯：跳到第一個答案爲工作斯威夫特3溶液。）

UITextField *searchBarTextField = [self.searchDisplayController.searchBar valueForKey:@"_searchField"]; 

// Magnifying glass icon. 
UIImageView *leftImageView = (UIImageView *)searchBarTextField.leftView; 
leftImageView.image = [LeftImageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate]; 
leftImageView.tintColor = [UIColor whiteColor]; 

// Clear button 
UIButton *clearButton = [searchBarTextField valueForKey:@"_clearButton"]; 
[clearButton setImage:[clearButton.imageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate] forState:UIControlStateNormal]; 
clearButton.tintColor = [UIColor whiteColor]; 

我嘗試翻譯斯威夫特：

let textField = searchController.searchBar.valueForKey("searchField") as! UITextField 
// These two work fine. 
textField.backgroundColor = UIColor.blackColor() 
textField.textColor = UIColor.blackColor() 

var glassIcon = textField.leftView 
// This would work. 
//glassIcon.hidden = true 

// This does not have any effect. 
//glassIcon?.tintColor = UIColor.whiteColor() 

// My attempt to translate, but it gives an error. 
glassIcon.image? = UIImage.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate) 

var clearButton = textField.valueForKey("clearButton")! 
      clearButton.setImage(clearButton.imageWithRenderingMode(.AlwaysTemplate), forState: .Normal) 
// This gives the error: "Cannot assign to property: 'clearButton' is immutable 
clearButton.tintColor = UIColor.whiteColor() 
    // Sorry for the weird formatting, it glitches here in the editor. 

的leftView似乎沒有圖像屬性。我如何以Objective-C代碼的形式訪問該屬性？ 另外，如果有更好的實現我想要的請讓我知道。

Answer 1

這裏是解決方案：

// Text field in search bar. 
let textField = searchController.searchBar.value(forKey: "searchField") as! UITextField 

let glassIconView = textField.leftView as! UIImageView 
glassIconView.image = glassIconView.image?.withRenderingMode(.alwaysTemplate) 
glassIconView.tintColor = UIColor.white 

let clearButton = textField.valueForKey("clearButton") as! UIButton 
clearButton.setImage(clearButton.imageView?.image?.withRenderingMode(.alwaysTemplate), for: .normal) 
clearButton.tintColor = UIColor.white