iPhone SDK：透明視圖中的非透明子視圖

我有一個已添加到我的UIView的子視圖。這個想法是，子視圖是一個與uibuttons懸停的面板。子視圖的字母爲0.2，因爲用戶需要能夠看到背後的內容。iPhone SDK：透明視圖中的非透明子視圖

問題是，當我向子視圖添加uibuttons時，它們從子視圖繼承alpha（我希望按鈕不透明並具有1.0的alpha）。我試圖通過遍歷uibuttons並將alpha設置回1.0來解決這個問題，但沒有成功。解決方案？

// 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; 
    }

來源

2009-09-11 Cliff Viegas

您應該使用alpha 1.0和透明背景色創建topHoverView。然後添加一個子視圖與黑色背景覆蓋用α0.2完整視圖，然後添加按鈕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; 
}

來源

2009-09-11 06:42:46

乾杯，很好的解決方法。 – 2009-09-11 07:16:59

謝謝菲利普，除了通過IB以外，我試圖做類似的事情，我只是無法獲得我想要的效果。但是你的解決方法幫助我獲得了它。 – sherry 2012-12-16 06:53:33

代替

topHoverView.backgroundColor = [UIColor transparentColor];

，下面的代碼是正確的。

topHoverView.backgroundColor = [UIColor clearColor];

來源

2010-08-18 04:45:22 alones

iPhone SDK：透明視圖中的非透明子視圖

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