UITextField rightViewMode無法正常工作

Question

我需要在UITextField上創建自定義清除按鈕，所以我使用的是RightView。代碼如下：

UIImage *clearImage = [[UIImage imageNamed:@"search-clear.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0.0,0.0, 0.0, 0.0)]; 
    UIImageView *clearImageView = [[UIImageView alloc]initWithImage:clearImage]; 

    UIButton *clearButton = [UIButton buttonWithType:UIButtonTypeCustom]; 
    clearButton.frame = clearImageView.frame; 
    [clearButton setBackgroundImage:clearImage forState:UIControlStateNormal]; 
    clearButton.backgroundColor = [UIColor clearColor]; 

    self.emailTextField.rightViewMode = UITextFieldViewModeWhileEditing; 
    self.emailTextField.rightView = clearButton; 
    self.emailTextField.clearButtonMode = UITextFieldViewModeNever; 

但是，按鈕沒有顯示在正確的時間。它顯示文本字段僅在文本長度爲0時的焦點。只要我開始輸入，它就會消失。我需要弄清楚如何替換和複製清除按鈕，以便它顯示字符串何時至少有一個字符。

Answer 1

你不能在同一時間同時顯示，但你可以做這樣的

UITextField * textfield = [[UITextField alloc] initWithFrame:CGRectMake(10, 100, 300, 40)]; 
[textfield setBorderStyle:UITextBorderStyleRoundedRect]; 

UIImageView * imgvw = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"search.jpeg"]]; 
[imgvw setFrame:CGRectMake(0, 0, 30, 30)]; 

[textfield setRightView:imgvw]; 
[textfield setRightViewMode:UITextFieldViewModeUnlessEditing]; 
[textfield setClearButtonMode:UITextFieldViewModeWhileEditing]; 

[self.view addSubview:textfield];