递归显示视图层次结构

// Recursively travel down the view tree, increasing the indentation level for children

- (void) dumpView: (UIView *) aView atIndent: (int) indent into:(NSMutableString *) outstring

{

    for (int i = 0; i < indent; i++)

        [outstring appendString:@"--"];

    [outstring appendFormat:@"[%2d] %@\n", indent, [[aView class] description]];

    

    for (UIView *view in [aView subviews])

        [self dumpView:view atIndent:indent + 1 into:outstring];

}

// Start the tree recursion at level 0 with the root view

- (NSString *) displayViews: (UIView *) aView

{

    NSMutableString *outstring = [[NSMutableString alloc] init];

    [self dumpView: self.view.window atIndent:0 into:outstring];

    return [outstring autorelease];

}

//=========================================================

// Return an exhaustive descent of the view's subviews
-(NSArray *)allSubviews:(UIView *)aView
{
    NSArray *results = [aView subviews];
    NSLog(@"%d", [results count]);
    
    for (UIView *eachView in [aView subviews])
    {
        NSArray *riz = [self allSubviews:eachView];
        if (riz) results = [results arrayByAddingObjectsFromArray:riz];
    }
    return results;
}

// Return all views throughout the application
-(NSArray *)allApplicationViews
{
    NSArray *results = [[UIApplication sharedApplication] windows];
    for (UIWindow *window in [[UIApplication sharedApplication] windows])
    {
        NSArray *riz = [self allSubviews:window];
        if (riz) results = [results arrayByAddingObjectsFromArray: riz];
    }
    return results;
}

// Return an array of parent views from the window down to the view
-(NSArray *)pathToView:(UIView *)aView
{
    NSMutableArray *array = [NSMutableArray arrayWithObject:aView];
    UIView *view = aView;
    UIWindow *window = aView.window;
    while (view != window)
    {
        view = [view superview];
        [array insertObject:view atIndex:0];
    }
    return array;
}

// Show the tree
- (void) displayViews
{
    NSLog(@"%@",[self displayViews: self.view.window]);
    
    //printf("Subviews of the main view:\n");
    //NSLog(@"%@", [self allSubviews:self.view]);
    
    printf("Path to each main subview:\n");
    for (UIView *eachView in [self allSubviews:self.view])
        NSLog(@"%@", [self pathToView:eachView]);
    
    // More views than you could dream of!
    //printf("\nAll window subviews:\n");
    //NSLog(@"%@", [self allApplicationViews]);
    
}