如何遍历 UIView 的所有子视图,以及它们的子视图和它们的子视图?
18 回答
使用递归:
// UIView+HierarchyLogging.h
@interface UIView (ViewHierarchyLogging)
- (void)logViewHierarchy;
@end
// UIView+HierarchyLogging.m
@implementation UIView (ViewHierarchyLogging)
- (void)logViewHierarchy
{
NSLog(@"%@", self);
for (UIView *subview in self.subviews)
{
[subview logViewHierarchy];
}
}
@end
// In your implementation
[myView logViewHierarchy];
好吧,这是我对 UIView 类使用递归和包装器(类别/扩展)的解决方案。
// UIView+viewRecursion.h
@interface UIView (viewRecursion)
- (NSMutableArray*) allSubViews;
@end
// UIView+viewRecursion.m
@implementation UIView (viewRecursion)
- (NSMutableArray*)allSubViews
{
NSMutableArray *arr=[[[NSMutableArray alloc] init] autorelease];
[arr addObject:self];
for (UIView *subview in self.subviews)
{
[arr addObjectsFromArray:(NSArray*)[subview allSubViews]];
}
return arr;
}
@end
用法:现在您应该循环遍历所有子视图并根据需要对其进行操作。
//disable all text fields
for(UIView *v in [self.view allSubViews])
{
if([v isKindOfClass:[UITextField class]])
{
((UITextField*)v).enabled=NO;
}
}
这是另一个 Swift 实现:
extension UIView {
var allSubviews: [UIView] {
return self.subviews.flatMap { [$0] + $0.allSubviews }
}
}
Swift 3 中的一个解决方案,它提供了所有subviews
内容而不包括视图本身:
extension UIView {
var allSubViews : [UIView] {
var array = [self.subviews].flatMap {$0}
array.forEach { array.append(contentsOf: $0.allSubViews) }
return array
}
}
刚刚通过调试器找到了一种有趣的方法:
http://idevrecipes.com/2011/02/10/exploring-iphone-view-hierarchies/
引用此 Apple 技术说明:
https://developer.apple.com/library/content/technotes/tn2239/_index.html#SECUIKIT
只需确保您的调试器已暂停(或者手动设置暂停的断点),您就可以请求recursiveDescription
.
我在创建时标记所有内容。然后很容易找到任何子视图。
view = [aView viewWithTag:tag];
这是一个具有实际视图循环和中断功能的示例。
迅速:
extension UIView {
func loopViewHierarchy(block: (_ view: UIView, _ stop: inout Bool) -> ()) {
var stop = false
block(self, &stop)
if !stop {
self.subviews.forEach { $0.loopViewHierarchy(block: block) }
}
}
}
调用示例:
mainView.loopViewHierarchy { (view, stop) in
if view is UIButton {
/// use the view
stop = true
}
}
反向循环:
extension UIView {
func loopViewHierarchyReversed(block: (_ view: UIView, _ stop: inout Bool) -> ()) {
for i in stride(from: self.highestViewLevel(view: self), through: 1, by: -1) {
let stop = self.loopView(view: self, level: i, block: block)
if stop {
break
}
}
}
private func loopView(view: UIView, level: Int, block: (_ view: UIView, _ stop: inout Bool) -> ()) -> Bool {
if level == 1 {
var stop = false
block(view, &stop)
return stop
} else if level > 1 {
for subview in view.subviews.reversed() {
let stop = self.loopView(view: subview, level: level - 1, block: block)
if stop {
return stop
}
}
}
return false
}
private func highestViewLevel(view: UIView) -> Int {
var highestLevelForView = 0
for subview in view.subviews.reversed() {
let highestLevelForSubview = self.highestViewLevel(view: subview)
highestLevelForView = max(highestLevelForView, highestLevelForSubview)
}
return highestLevelForView + 1
}
}
调用示例:
mainView.loopViewHierarchyReversed { (view, stop) in
if view is UIButton {
/// use the view
stop = true
}
}
目标-C:
typedef void(^ViewBlock)(UIView* view, BOOL* stop);
@interface UIView (ViewExtensions)
-(void) loopViewHierarchy:(ViewBlock) block;
@end
@implementation UIView (ViewExtensions)
-(void) loopViewHierarchy:(ViewBlock) block {
BOOL stop = NO;
if (block) {
block(self, &stop);
}
if (!stop) {
for (UIView* subview in self.subviews) {
[subview loopViewHierarchy:block];
}
}
}
@end
调用示例:
[mainView loopViewHierarchy:^(UIView* view, BOOL* stop) {
if ([view isKindOfClass:[UIButton class]]) {
/// use the view
*stop = YES;
}
}];
在 Ole Begemann 的帮助下。我添加了几行来将块概念融入其中。
UIView+HierarchyLogging.h
typedef void (^ViewActionBlock_t)(UIView *);
@interface UIView (UIView_HierarchyLogging)
- (void)logViewHierarchy: (ViewActionBlock_t)viewAction;
@end
UIView+HierarchyLogging.m
@implementation UIView (UIView_HierarchyLogging)
- (void)logViewHierarchy: (ViewActionBlock_t)viewAction {
//view action block - freedom to the caller
viewAction(self);
for (UIView *subview in self.subviews) {
[subview logViewHierarchy:viewAction];
}
}
@end
在 ViewController 中使用 HierarchyLogging 类别。你现在可以自由地去做你需要做的事情。
void (^ViewActionBlock)(UIView *) = ^(UIView *view) {
if ([view isKindOfClass:[UIButton class]]) {
NSLog(@"%@", view);
}
};
[self.view logViewHierarchy: ViewActionBlock];
这是一个递归代码:-
for (UIView *subViews in yourView.subviews) {
[self removSubviews:subViews];
}
-(void)removSubviews:(UIView *)subView
{
if (subView.subviews.count>0) {
for (UIView *subViews in subView.subviews) {
[self removSubviews:subViews];
}
}
else
{
NSLog(@"%i",subView.subviews.count);
[subView removeFromSuperview];
}
}
无需创建任何新功能。只需在使用 Xcode 进行调试时执行此操作。
在视图控制器中设置断点,并使应用程序在此断点处暂停。
右键单击空白区域,然后在 Xcode 的 Watch 窗口中按“Add Expression...”。
输入这一行:
(NSString*)[self->_view recursiveDescription]
如果该值太长,请右键单击它并选择“打印...的描述”。您将在控制台窗口中看到 self.view 的所有子视图。如果您不想看到 self.view 的子视图,请将 self->_view 更改为其他内容。
完毕!没有gdb!
顺便说一句,我做了一个开源项目来帮助完成这类任务。这真的很简单,并且使用 Objective-C 2.0 块在层次结构中的所有视图上执行代码。
https://github.com/egold/UIViewRecursion
例子:
-(void)makeAllSubviewsGreen
{
[self.view runBlockOnAllSubviews:^(UIView *view) {
view.backgroundColor = [UIColor greenColor];
}];
}
这是上面Ole Begemann 答案的变体,它添加了缩进来说明层次结构:
// UIView+HierarchyLogging.h
@interface UIView (ViewHierarchyLogging)
- (void)logViewHierarchy:(NSString *)whiteSpaces;
@end
// UIView+HierarchyLogging.m
@implementation UIView (ViewHierarchyLogging)
- (void)logViewHierarchy:(NSString *)whiteSpaces {
if (whiteSpaces == nil) {
whiteSpaces = [NSString string];
}
NSLog(@"%@%@", whiteSpaces, self);
NSString *adjustedWhiteSpaces = [whiteSpaces stringByAppendingFormat:@" "];
for (UIView *subview in self.subviews) {
[subview logViewHierarchy:adjustedWhiteSpaces];
}
}
@end
此答案中发布的代码遍历所有窗口和所有视图及其所有子视图。它用于将视图层次结构的打印输出转储到 NSLog,但您可以将其用作任何视图层次结构遍历的基础。它使用递归 C 函数来遍历视图树。
前段时间我写了一个类别来调试一些视图。
IIRC,发布的代码是有效的。如果没有,它将为您指明正确的方向。使用风险自负等。
这也显示了层次结构级别
@implementation UIView (ViewHierarchyLogging)
- (void)logViewHierarchy:(int)level
{
NSLog(@"%d - %@", level, self);
for (UIView *subview in self.subviews)
{
[subview logViewHierarchy:(level+1)];
}
}
@end
希望我先找到这个页面,但是如果(出于某种原因)您想以非递归方式执行此操作,而不是在类别中,并且使用更多代码行
我认为所有使用递归的答案(调试器选项除外)都使用了类别。如果您不需要/想要一个类别,您可以只使用实例方法。例如,如果您需要获取视图层次结构中所有标签的数组,您可以这样做。
@interface MyViewController ()
@property (nonatomic, retain) NSMutableArray* labelsArray;
@end
@implementation MyViewController
- (void)recursiveFindLabelsInView:(UIView*)inView
{
for (UIView *view in inView.subviews)
{
if([view isKindOfClass:[UILabel class]])
[self.labelsArray addObject: view];
else
[self recursiveFindLabelsInView:view];
}
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
self.labelsArray = [[NSMutableArray alloc] init];
[self recursiveFindLabelsInView:self.view];
for (UILabel *lbl in self.labelsArray)
{
//Do something with labels
}
}
下面的方法创建一个或多个可变数组,然后循环输入视图的子视图。这样做时,它会添加初始子视图,然后查询该子视图是否有任何子视图。如果为真,它会再次调用自己。这样做直到添加了层次结构的所有视图。
-(NSArray *)allSubs:(UIView *)view {
NSMutableArray * ma = [NSMutableArray new];
for (UIView * sub in view.subviews){
[ma addObject:sub];
if (sub.subviews){
[ma addObjectsFromArray:[self allSubs:sub]];
}
}
return ma;
}
调用使用:
NSArray * subviews = [self allSubs:someView];