在 iOS7 中，UISearchBar 搜索图标未左对齐

Question

在iOS7中，搜索图标和占位符文本始终出现在中间。我尝试将搜索栏中文本字段的文本对齐方式更改为左对齐，但没有作用。 有没有办法让搜索栏的搜索图标在iOS7中左对齐显示？

我尝试了以下几行代码，但它们没有起作用：

UITextField *txfSearchField = [_searchBar valueForKey:@"_searchField"];
txfSearchField.textAlignment = NSTextAlignmentLeft;

[_searchArticle setImage:image forSearchBarIcon:UISearchBarIconSearch    state:UIControlStateNormal];
UIimageView *im = [UIImageView alloc]init];
im.image = image;
txfSearchField.leftView =im;

- user1907370

Answer 1

无法更改搜索栏占位文本的对齐方式，我尝试了很多“SO”答案，但没有一个起作用。最终，我采用了这个解决方法：

在占位文本右侧留出一些空白。

    if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_6_1) {
        // Load resources for iOS 6.1 or earlier
        self.searchBar.placeholder = @"hello";
   } else {
       // Load resources for iOS 7 or later
       self.searchBar.placeholder = @"hello             ";
  }

享受吧！！

- kmithi1

---

如果我的占位符文本不是常量，我该怎么办？ - jAckOdE

@jAckOdE 使用此方法获取字符串大小 sizeWithFont: constrainedToSize: lineBreakMode:。 - kmithi1

这个方法用于计算文本的大小，在我的情况下需要进行逆向计算：确定适合大小的文本字符串。据我所知，没有直接的方法可以做到这一点，但我认为我们可以通过循环并增加尾部空格的数量，直到字符串适应文本字段的大小。虽然这不是一个很好的解决方案。 - jAckOdE

@kmithi，您是否已经提交了使用此代码的应用程序？它已经被批准了吗？ - Don Miguel

Answer 2

在 Swift-3 中：

放大镜图标可以通过在搜索栏上添加子视图并将默认的放大镜图标设为 null 来左对齐。

let width = 20
let height = 20
func changeSearchBarIcon() {
        let topView: UIView = searchBar.subviews[0] as UIView
        var searchField:UITextField!
        for subView in topView.subviews {
            if subView is UITextField {
                searchField = subView as! UITextField
                break
            }
        }

        if ((searchField) != nil) {
            let leftview = searchField.leftView as! UIImageView
            let magnifyimage = leftview.image
            let imageView  = UIImageView(frame: CGRect(x: searchBar.frame.origin.x  , y:  10, width: width, height: height ) )
            imageView.image = magnifyimage

            searchField.leftView = UIView(frame: CGRect(x: 0 , y: 0, width: width, height: height) )
            searchField.leftViewMode = .always
            searchField.superview?.addSubview(imageView)
        }
    }

- Shrawan

Answer 3

这不是一个很好的解决方案，但它可以工作。（在iOS 9上测试）

import UIKit

class MySearchBar: UISearchBar {

    override func layoutSubviews() {
        super.layoutSubviews()
        if let l = getTextFieldLabel() {
            l.addObserver(self, forKeyPath: "frame", options: .New, context: nil)
        }
        if let i = getIcon() {
            i.addObserver(self, forKeyPath: "frame", options: .New, context: nil)
        }
    }

    override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context:     UnsafeMutablePointer<Void>) {

        if let l = object as? UILabel {
            l.removeObserver(self, forKeyPath: "frame")
            l.frame = CGRect(x: 29, y: 1, width: 323, height: 25)
            l.addObserver(self, forKeyPath: "frame", options: .New, context: nil)
        }

        if let i = object as? UIImageView {
            i.removeObserver(self, forKeyPath: "frame")
            i.frame = CGRect(x: 8, y: 7.5, width: 13, height: 13)
            i.addObserver(self, forKeyPath: "frame", options: .New, context: nil)
        }
    }

    func getTextFieldLabel() -> UILabel? {
        for v in self.allSubViews(self) {
            if NSStringFromClass(v.dynamicType) == "UISearchBarTextFieldLabel" {
                return v as? UILabel
            }
        }
        return nil
    }

    func getIcon() -> UIImageView? {
        for v in self.allSubViews(self) {
            if NSStringFromClass(v.dynamicType) == "UIImageView" {
                return v as? UIImageView
            }
        }
        return nil
    }

    func allSubViews( v : UIView!) -> [UIView] {
        var views : [UIView] = []
        views += v.subviews
        for s in v.subviews {
            views += allSubViews(s)
        }
        return views
    }    
}

- PowHu

Answer 4

iOS 9的解决方法：

extension ViewController: UISearchBarDelegate {

    func searchBarShouldBeginEditing(searchBar: UISearchBar) -> Bool {
        if let searchTextField = searchBar.valueForKey("_searchField") as? UITextField {
            if let placeholderLabel = searchTextField.valueForKey("_placeholderLabel") as? UILabel {
                if searchTextField.textColor == placeholderLabel.textColor {
                    searchTextField.text = ""
                    searchTextField.textColor = UIColor.blackColor()
                    searchTextField.clearButtonMode = .Always
                }
            }
        }
        return true
    }

    func searchBarSearchButtonClicked(searchBar: UISearchBar) {
        if searchBar.text == "" {
            if let searchTextField = searchBar.valueForKey("_searchField") as? UITextField {
                if let placeholderLabel = searchTextField.valueForKey("_placeholderLabel") as? UILabel {
                    searchBar.text = "Placeholder"
                    searchTextField.textColor = placeholderLabel.textColor
                    searchTextField.clearButtonMode = .Never
                }
            }
        }
        searchBar.resignFirstResponder()
    }

}

- Konstantin Cherkasov

Answer 5

您可以调用此方法，它看起来像屏幕截图： {{link1：}}。

+(void)customizeDisplayForSeachbar:(UISearchBar *)searchBar
{ 
   searchBar.barTintColor = [UIColor whiteColor];
   searchBar.layer.borderWidth = 0.0;
   searchBar.layer.borderColor = [UIColor clearColor].CGColor;

    UITextField *txfSearchField = [searchBar valueForKey:@"_searchField"];
    UIImage *imageIcon=[UIImage imageNamed:@"search_icon.png"];
    float iconWidth=14;
    UIImageView *imgView=[[UIImageView alloc] initWithFrame:CGRectMake(15, (txfSearchField.superview.frame.size.height-iconWidth)/2-1, iconWidth, iconWidth)];
    imgView.contentMode=UIViewContentModeScaleAspectFit;
    imgView.image=imageIcon;
    txfSearchField.leftView=[[UIView alloc] initWithFrame:CGRectMake(0, 0, 10, 40)];
    txfSearchField.leftViewMode=UITextFieldViewModeAlways;
    [txfSearchField.superview addSubview:imgView];
}

- Loquatious

Answer 6

1 子类化 uitextField

2 在 initWithFrame 中实现

  [self setBackgroundColor:[UIColor clearColor]];
        [self setTextAlignment:NSTextAlignmentLeft];
        [self setContentVerticalAlignment:UIControlContentVerticalAlignmentCenter];
        [self setAutocorrectionType:UITextAutocorrectionTypeNo];
        [self setAutocapitalizationType:UITextAutocapitalizationTypeNone];
        [self setPlaceholder:@"Search"];
        [self setLeftView:[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"search-icon"]]];
        [self setLeftViewMode:UITextFieldViewModeAlways];

在主类中包含UItextfieldDelegate并实现以下委托方法

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    NSString* searchString = [textField.text stringByReplacingCharactersInRange:range withString:string];

    searchYourFriendsArray = [[NSMutableArray alloc] init];

    if(searchString.length > 0 )
    {
        NSMutableArray *searchArray = [NSMutableArray arrayWithArray:yourFriendsArray];
        NSPredicate *predicate  = [NSPredicate predicateWithFormat:@"FirstName beginswith[C] %@ OR LastName beginswith[C] %@",searchString,searchString];
        searchYourFriendsArray  = [NSMutableArray arrayWithArray:[searchArray filteredArrayUsingPredicate:predicate]];

       }

    return YES;
}

- Muruganandham K