可可触摸:创建和添加自定义视图
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24-10-2019 - |
题
我在Cocoa Touch中创建一个自定义视图,该视图被UIView超级分类,在我的主控制器中,我初始化它,然后将其添加为主视图的子视图,但是当我将其添加到主视图中时,它再次调用我的初始化器方法并引起原因。无限循环。我要创建错误的自定义视图吗?这是主景
- (void)loadView {
UIImage* tempImage = [UIImage imageNamed: @"image1.jpg"];
CustomImageContainer *testImage = [[CustomImageContainer alloc] initWithImage: tempImage andLabel: @"test image" onTop: true atX: 10 atY: 10];
[self.view addSubview: testImage];
}
和自定义iMageContainer
-(CustomImageContainer *) initWithImage: (UIImage *)imageToAdd andLabel: (NSString *)text onTop: (BOOL) top atX: (int) x_cord atY: (int) y_cord{
UIImageView *imageview_to_add = [[UIImageView alloc] initWithImage: imageToAdd];
imageview_to_add.frame = CGRectMake(0, 0, imageToAdd.size.width, imageToAdd.size.height);
UILabel *label_to_add = [[UILabel alloc] init];
label_to_add.text = text;
label_to_add.alpha = 50;
label_to_add.backgroundColor = [UIColor blackColor];
label_to_add.textColor = [UIColor whiteColor];
[self addSubview: imageview_to_add];
self.frame = CGRectMake(x_cord, y_cord, imageToAdd.size.width, imageToAdd.size.height);
if (top) {
label_to_add.frame = CGRectMake(0, 0, imageview_to_add.frame.size.width, imageview_to_add.frame.size.height);
//[self addSubview: label_to_add];
}
else {
label_to_add.frame = CGRectMake(0,.2 * imageview_to_add.frame.size.height, imageview_to_add.frame.size.width, imageview_to_add.frame.size.height);
}
[self addSubview: label_to_add];
[super init];
return self;
}
解决方案
你为什么把 [super init]
初始化器末尾的语句?子类别时,通常您将此语句放在方法的开头。
为了 uiview 子类,在代码中创建视图时指定的初始化程序为 initWithFrame:
, ,因此,您应该在添加标签和图像之前调用它。您可以使用图像来计算自定义视图所需的框架。
-(CustomImageContainer *) initWithImage: (UIImage *)imageToAdd andLabel: (NSString *)text onTop: (BOOL) top atX: (int) x_cord atY: (int) y_cord{
// The view will gets its frame to the size of the image
UIImageView *imageview_to_add = [[UIImageView alloc] initWithImage: imageToAdd];
// Call the designated initializer
CGRect frame = CGRectMake(x_cord, y_cord, imageToAdd.size.width, imageToAdd.size.height);
self = [super initWithFrame:frame];
[self addSubview: imageview_to_add];
UILabel *label_to_add = [[UILabel alloc] init];
label_to_add.text = text;
label_to_add.alpha = 50;
label_to_add.backgroundColor = [UIColor blackColor];
label_to_add.textColor = [UIColor whiteColor];
if (top) {
label_to_add.frame = CGRectMake(0, 0, imageview_to_add.frame.size.width, imageview_to_add.frame.size.height);
}
else {
label_to_add.frame = CGRectMake(0,.2 * imageview_to_add.frame.size.height, imageview_to_add.frame.size.width, imageview_to_add.frame.size.height);
}
[self addSubview: label_to_add];
return self;
}
如果您仍然有一个无限的循环,请暂停调试器并在堆栈跟踪中搜索复发方法模式。此模式将为您提供代码进入无限循环的位置。
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