[英]How to show image when textfield is empty only?
我有4個文本字段,一個按鈕和一個圖像,我要實現的目標是,當按下按鈕時,它應該警告用戶有空的文本字段並顯示指向空文本字段的圖像,但是使用戶將文本放入空白文本字段時,圖像消失。 謝謝
這是我的功能
func checkFields(){
let userEmail = user_EmailTxtField.text!
let userPassword = user_PassTxtField.text!
let passwordConfirm = pass_ConfirmTxtField.text!
let userPhone = user_PhoneTxtField.text!
//Set backArrow image to show input error to password
let imageName = "backArrow.png"
let image = UIImage(named: imageName)
let passImageView1 = UIImageView(image: image!)
passImageView1.frame = CGRect(x: 319, y: 331, width: 49, height: 49)
view.addSubview(passImageView1)
//Show Arrow image to password confirm error
let passConfirmImageView1 = UIImageView(image: image!)
passConfirmImageView1.frame = CGRect(x: 319, y: 394, width: 49, height: 49)
view.addSubview(passConfirmImageView1)
//Show arrow Image to email error
let emailImageView1 = UIImageView(image: image!)
emailImageView1.frame = CGRect(x: 319, y: 270, width: 49, height: 49)
view.addSubview(emailImageView1)
//Set image to phonetxt field error
let phoneImageView1 = UIImageView(image: image!)
phoneImageView1.frame = CGRect(x: 319, y: 209, width: 49, height: 49)
view.addSubview(phoneImageView1)
if userPhone.isEmpty {
phoneImageView1.isHidden = false
} else {
phoneImageView1.isHidden = true
}
if userEmail.isEmpty {
emailImageView1.isHidden = false
}
if userPassword.isEmpty {
passImageView1.isHidden = false
}
if passwordConfirm.isEmpty {
passConfirmImageView1.isHidden = false
}
}
您應該將圖像的創建(addSubview)和檢查
將創建內容放入viewDidLoad
然后檢查這些字段並隱藏或顯示它。
剛才您每次都創建一個新圖像放置在先前創建的圖像上(如果您切換到線框3d調試視圖,則可以檢查此項)
而不是檢查if userPhone.isEmpty
是否應該嘗試:
if user_EmailTxtField.text == nil {
phoneImageView1.isHidden = false
}
您甚至可以:
if user_EmailTxtField.text == nil || user_EmailTxtField.text == "" {
phoneImageView1.isHidden = false
}
您可以調用一個函數來處理檢查,然后在文本不為空的情況下隱藏圖像,如下所示:
1在為事件.editingChanged
創建.editingChanged
的位置,將一個目標添加到textField中:
user_EmailTxtField.addTarget(self, action: #selector(textFieldDidChange), for: .editingChanged)
user_PhoneTxtField.addTarget(self, action: #selector(textFieldDidChange), for: .editingChanged)
pass_ConfirmTxtField.addTarget(self, action: #selector(textFieldDidChange), for: .editingChanged)
pass_ConfirmTxtField.addTarget(self, action: #selector(textFieldDidChange), for: .editingChanged)
2設置用於檢查文本字段是否被編輯的方法:
func textFieldDidChange() {
emailImageView1.isHidden = user_EmailTxtField.hasText
phoneImageView1.isHidden = user_PhoneTxtField.hasText
passImageView1.isHidden = pass_ConfirmTxtField.hasText
passConfirmImageView1.isHidden = pass_ConfirmTxtField.hasText
}
因此,如果將此示例應用於所有文本字段,則不需要在checkFields()
進行檢查,並且可以將方法重命名為setupTextFields()
,例如,僅將其用於創建文本字段
在類的所有方法中使用圖像視圖的示例,但請確保例如在viewDidLoad()
進行初始化,以避免在解開可選值時發現nil錯誤
class YourClass: UIViewController {
// ImageView Reference
var emailImageView1: UIImageView!
// then your checkFields method
func checkFields() {
// code before
emailImageView1 = UIImageView(image: image!)
// code after
}
}
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