Disabale UIButton

Question

禁用按鈕時。不透明度降低到50％。是有什麼辦法可以降低不透明度爲25％

Answer 1

我將繼承的UIButton並重寫的setEnabled：方法是這樣的：

- (void) setEnabled:(BOOL)enabled { 
    NSLog(@"Button enabled = %d", enabled); 
    [super setEnabled:enabled]; 


    UIColor *color = self.backgroundColor; 
    if (!self.isEnabled) { 
     self.backgroundColor = [color colorWithAlphaComponent:0.75]; 
    } else { 
     self.backgroundColor = [color colorWithAlphaComponent:1.0]; 
    } 
} 

Answer 2

傑克·考克斯的回答迅速版：

override var enabled: Bool{ 
    didSet { 
     if enabled { 
      self.backgroundColor = self.backgroundColor?.colorWithAlphaComponent(1) 
     } else { 
      self.backgroundColor = self.backgroundColor?.colorWithAlphaComponent(0.75) 
     } 
    } 
}