iPhone SDK：透明视图中的非透明子视图

我有一个已添加到我的UIView的子视图。这个想法是，子视图是一个与uibuttons悬停的面板。子视图的字母为0.2，因为用户需要能够看到背后的内容。iPhone SDK：透明视图中的非透明子视图

问题是，当我向子视图添加uibuttons时，它们从子视图继承alpha（我希望按钮不透明并具有1.0的alpha）。我试图通过遍历uibuttons并将alpha设置回1.0来解决这个问题，但没有成功。解决方案？

// Create the subview and add it to the view 
    topHoverView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 50)]; 
    topHoverView.backgroundColor = [UIColor blackColor]; 
    [topHoverView setAlpha:0.2]; 
    [self.view addSubview:topHoverView]; 

    // Add button 1 
    button1 = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
    [button1 setFrame:CGRectMake(20, 10, 80, 30)]; 
    [button1 setTitle:@"New" forState:UIControlStateNormal]; 
    [button1 addTarget:self action:@selector(button1Action:) forControlEvents:UIControlEventTouchUpInside]; 
    [topHoverView addSubview:button1]; 

    // Add button 2 
    button2 = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
    [button2 setFrame:CGRectMake(120, 10, 80, 30)]; 
    [button2 setTitle:@"Clear" forState:UIControlStateNormal]; 
    [button2 addTarget:self action:@selector(button2Action:) forControlEvents:UIControlEventTouchUpInside]; 
    [topHoverView addSubview:button2]; 

    // Add button 3 
    button3 = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
    [button3 setFrame:CGRectMake(220, 10, 80, 30)]; 
    [button3 setTitle:@"Delete" forState:UIControlStateNormal]; 
    [button3 addTarget:self action:@selector(button3Action:) forControlEvents:UIControlEventTouchUpInside]; 
    [topHoverView addSubview:d button3]; 

    // Attempt to iterate through the subviews (buttons) to set their transparency back to 1.0 
    for (UIView *subView in topHoverView.subviews) { 
     subView.alpha = 1.0; 
    }

来源

2009-09-11 Cliff Viegas

您应该使用alpha 1.0和透明背景色创建topHoverView。然后添加一个子视图与黑色背景覆盖用α0.2完整视图，然后添加按钮topHoverView：

// Create the subview and add it to the view 
topHoverView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 50)]; 
topHoverView.backgroundColor = [UIColor transparentColor]; 
[topHoverView setAlpha:1.0]; 
[self.view addSubview:topHoverView]; 

canvasView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 50)]; 
canvasView.backgroundColor = [UIColor blackColor]; 
[canvasViewView setAlpha:0.2]; 
[topHoverView.view addSubview:canvasView]; 

// Add button 1 
button1 = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
[button1 setFrame:CGRectMake(20, 10, 80, 30)]; 
[button1 setTitle:@"New" forState:UIControlStateNormal]; 
[button1 addTarget:self action:@selector(button1Action:) forControlEvents:UIControlEventTouchUpInside]; 
[topHoverView addSubview:button1]; 

// Add button 2 
button2 = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
[button2 setFrame:CGRectMake(120, 10, 80, 30)]; 
[button2 setTitle:@"Clear" forState:UIControlStateNormal]; 
[button2 addTarget:self action:@selector(button2Action:) forControlEvents:UIControlEventTouchUpInside]; 
[topHoverView addSubview:button2]; 

// Add button 3 
button3 = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
[button3 setFrame:CGRectMake(220, 10, 80, 30)]; 
[button3 setTitle:@"Delete" forState:UIControlStateNormal]; 
[button3 addTarget:self action:@selector(button3Action:) forControlEvents:UIControlEventTouchUpInside]; 
[topHoverView addSubview:d button3]; 

// Attempt to iterate through the subviews (buttons) to set their transparency back to 1.0 
for (UIView *subView in topHoverView.subviews) { 
    subView.alpha = 1.0; 
}

来源

2009-09-11 06:42:46

干杯，很好的解决方法。 – 2009-09-11 07:16:59

谢谢菲利普，除了通过IB以外，我试图做类似的事情，我只是无法获得我想要的效果。但是你的解决方法帮助我获得了它。 – sherry 2012-12-16 06:53:33

代替

topHoverView.backgroundColor = [UIColor transparentColor];

，下面的代码是正确的。

topHoverView.backgroundColor = [UIColor clearColor];

来源

2010-08-18 04:45:22 alones

iPhone SDK：透明视图中的非透明子视图

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