添加效果选择器的源码，稍后集成到照片效果中。可以选择多重效果，进行叠加。也可以随机选择效果。

AmzPhoto/DialController/DialController.h

@@ -0,0 +1,41 @@
+//
+//  Created by Dimitris Doukas on 25/03/2011.
+//  Copyright 2011 doukasd.com. All rights reserved.
+//
+
+#import <UIKit/UIKit.h>
+
+@protocol DialControllerDelegate;
+
+@interface DialController : UIViewController <UITableViewDelegate, UITableViewDataSource> {
+    UITableView *tableView;
+    BOOL isSpinning;    //refers to wether the user is spinning it
+    BOOL isAnimating;   //refers to wether it is animating into position
+    NSArray *strings;
+    NSInteger selectedStringIndex;
+    NSString *selectedString;
+    id<DialControllerDelegate> delegate;
+}
+
+@property (nonatomic, retain) UITableView *tableView;
+@property (nonatomic, retain) NSArray *strings;
+
+@property (nonatomic, copy) NSString *selectedString;
+
+@property (readonly) NSInteger selectedStringIndex;
+@property BOOL isSpinning;
+
+@property (nonatomic, assign) id<DialControllerDelegate> delegate;
+
+- (id)initWithDialFrame:(CGRect)frame strings:(NSArray *)dialStrings;
+- (void)spinToRandomString;
+- (void)spinToString:(NSString *)string;
+
+@end
+
+
+@protocol DialControllerDelegate <NSObject>
+- (void)dialControllerDidSpin:(DialController *)controller;
+@required
+- (void)dialController:(DialController *)dial didSnapToString:(NSString *)string;
+@end

AmzPhoto/DialController/DialController.m

@@ -0,0 +1,262 @@
+//
+//  Created by Dimitris Doukas on 25/03/2011.
+//  Copyright 2011 doukasd.com. All rights reserved.
+//
+
+#import "DialController.h"
+#import "GlowLabel.h"
+
+#define NUM_ROWS            500000
+#define ROW_HEIGHT          60
+
+
+@interface DialController (PrivateMethods)
+- (void)snap;
+- (NSInteger)indexOfString:(NSString *)string;
+@end
+
+
+@implementation DialController
+
+@synthesize tableView, strings, selectedString;
+@synthesize isSpinning;
+@synthesize delegate;
+
+static NSString *CellIdentifier = @"DialCell";
+static const int kGlowLabelTag = 2011;
+
+- (void)dealloc
+{
+    self.tableView = nil;
+    self.strings = nil;
+    self.selectedString = nil;
+    [super dealloc];
+}
+
+- (id)initWithDialFrame:(CGRect)frame strings:(NSArray *)dialStrings {
+    self = [super init];
+    if (self) {
+        self.isSpinning = NO;
+        isAnimating = NO;
+
+        //validate the data
+        //check if the strings are more than 0. If they are not, create a default array
+        if (dialStrings == nil || [dialStrings count] == 0) {
+            dialStrings = [NSArray arrayWithObjects:@"0", nil];
+        }
+
+#warning this implementation does not like duplicate strings. each string in the values of the dial has to be different that the others
+        //check if the strings contain duplicates
+        //...
+
+        self.strings = dialStrings;
+
+        self.view = [[[UIView alloc] initWithFrame:frame] autorelease];
+
+        self.tableView = [[[UITableView alloc] initWithFrame:CGRectMake(0, 0, frame.size.width, frame.size.height) style:UITableViewStylePlain] autorelease];
+        self.tableView.delegate = self;
+        self.tableView.dataSource = self;
+        self.tableView.rowHeight = ROW_HEIGHT;
+        self.tableView.showsVerticalScrollIndicator = NO;
+        self.tableView.showsHorizontalScrollIndicator = NO;
+        self.tableView.separatorColor = [UIColor colorWithRed:110.0/255.0 green:110.0/255.0 blue:110.0/255.0 alpha:1.0];
+        self.tableView.backgroundColor = [UIColor colorWithRed:88.0/255.0 green:88.0/255.0 blue:88.0/255.0 alpha:1.0];
+        [self.view addSubview:self.tableView];
+
+        //INIT
+        //select a row in the middle
+        [self.tableView selectRowAtIndexPath:[NSIndexPath indexPathForRow:(int)(NUM_ROWS * .5) inSection:0] animated:NO scrollPosition:UITableViewScrollPositionMiddle];
+        [self snap];
+
+        //select random value
+        //[self spinToRandomValue];
+    }
+    return self;
+}
+
+- (void)didReceiveMemoryWarning
+{
+    // Releases the view if it doesn't have a superview.
+    [super didReceiveMemoryWarning];
+
+    // Release any cached data, images, etc that aren't in use.
+}
+
+#pragma mark - View lifecycle
+
+// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
+- (void)viewDidLoad {
+    [super viewDidLoad];
+}
+
+- (void)viewDidUnload
+{
+    [super viewDidUnload];
+    // Release any retained subviews of the main view.
+    // e.g. self.myOutlet = nil;
+}
+
+- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
+{
+    // Return YES for supported orientations
+    return (interfaceOrientation == UIInterfaceOrientationPortrait);
+}
+
+- (void)spinToRandomString {
+    [self spinToString:[self.strings objectAtIndex:arc4random() % [self.strings count]]];
+}
+
+- (void)spinToString:(NSString *)string {
+    isAnimating = NO;
+    self.isSpinning = NO;
+    if ([[self.tableView visibleCells] count] == 0) {
+        return;
+    }
+    //take any visible cell, find it's value's index, compute the difference to the index of the new value and scroll to that cell
+    UITableViewCell *cell = [[self.tableView visibleCells] objectAtIndex:0];
+    GlowLabel *label = (GlowLabel *)[cell viewWithTag:kGlowLabelTag];
+    int difference = [self indexOfString:string] - [self indexOfString:label.text];
+    [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:[self.tableView indexPathForCell:cell].row + difference inSection:0] atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
+}
+
+- (void)snap {
+    if (isAnimating) return;
+    isAnimating = YES;
+
+    self.isSpinning = NO;
+
+    //calculate vertical padding
+    double verticalPadding = (self.tableView.frame.size.height - self.tableView.rowHeight) * .5;
+
+    //for each cell, check if it is in view and set it to selected accordingly
+    for (int i=0; i<[[self.tableView visibleCells] count]; i++) {
+        UITableViewCell *cell = [[self.tableView visibleCells] objectAtIndex:i];
+        GlowLabel *label = (GlowLabel *)[cell viewWithTag:kGlowLabelTag];
+        BOOL selected = CGRectContainsPoint(CGRectMake(0, self.tableView.contentOffset.y + verticalPadding, self.tableView.frame.size.width, self.tableView.rowHeight), cell.center);
+        [label setSelected:selected];
+        if (selected) {
+            isAnimating = YES;
+            self.isSpinning = NO;
+            //self.selectedValue = [self.values objectAtIndex:[label.text intValue]];
+            self.selectedString = label.text;
+            [self.tableView scrollToRowAtIndexPath:[self.tableView indexPathForCell:cell] atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
+
+            //check if snappin will not result in an animation. in that case, call the delegate here
+            if ([self.tableView rectForRowAtIndexPath:[self.tableView indexPathForCell:cell]].origin.y == self.tableView.contentOffset.y + (self.tableView.frame.size.height - ROW_HEIGHT) * .5) {
+                NSLog(@"snap will not animate!");
+
+                [self.delegate dialController:self didSnapToString:self.selectedString];
+                isAnimating = NO;
+            }
+        }
+    }
+}
+
+/*
+#pragma mark UITableViewDelegate methods
+
+- (void)tableView:(UITableView *)aTableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath {
+}
+
+- (void)tableView:(UITableView *)aTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
+}
+*/
+
+#pragma mark UITableViewDataSource methods
+
+- (UITableViewCell *)tableView:(UITableView *)aTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
+
+    int cellNumber = indexPath.row % [self.strings count];
+
+    UITableViewCell *cell = (UITableViewCell *)[aTableView dequeueReusableCellWithIdentifier:CellIdentifier];
+    if (cell == nil) {
+        cell = [[[UITableViewCell alloc] initWithFrame:CGRectMake(0, 0, self.tableView.frame.size.width, self.tableView.rowHeight) reuseIdentifier:CellIdentifier] autorelease];
+        //make the cell unselectable
+        cell.selectionStyle = UITableViewCellSelectionStyleNone;
+
+        //add the glow label
+        GlowLabel *label = [[GlowLabel alloc] initWithFrame:CGRectMake(0, -8, self.tableView.frame.size.width, ROW_HEIGHT)];
+        label.unselectedColor = [UIColor colorWithRed:180.0/255.0 green:180.0/255.0 blue:180.0/255.0 alpha:1.0];
+        label.text = [NSString stringWithFormat:@"%@", [self.strings objectAtIndex:cellNumber]];
+        label.tag = kGlowLabelTag;
+
+        //add a background label
+        UILabel *bgLabel = [[UILabel alloc] initWithFrame:label.frame];
+        bgLabel.text =@"8";
+        bgLabel.textAlignment = label.textAlignment;
+        bgLabel.font = label.font;
+        bgLabel.backgroundColor = label.backgroundColor;
+        bgLabel.textColor = [UIColor colorWithRed:110.0/255.0 green:110.0/255.0 blue:110.0/255.0 alpha:1.0];
+
+        [cell addSubview:bgLabel];
+        [bgLabel release];
+
+        [cell addSubview:label];
+        [label release];
+    }
+    else {
+        //if a cell was dequeued, populate it with the relevant info and set is as unselected
+        GlowLabel *label = (GlowLabel *)[cell viewWithTag:kGlowLabelTag];
+        label.text = [NSString stringWithFormat:@"%@", [self.strings objectAtIndex:cellNumber]];
+        [label setSelected:NO];
+    }
+    return cell;
+}
+
+- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
+    return NUM_ROWS;
+}
+
+#pragma mark UIScrollViewDelegate methods
+
+- (void)scrollViewDidScroll:(UIScrollView *)scrollView {    
+    self.isSpinning = YES;
+    [self.delegate dialControllerDidSpin:self];
+}
+
+- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
+    if (!decelerate) {
+        self.isSpinning = NO;
+        isAnimating = NO;
+        [self snap];
+    }
+}
+
+- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
+    self.isSpinning = NO;
+    isAnimating = NO;
+    [self snap];
+}
+
+- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView {
+    if (isAnimating) {
+        isAnimating = NO;
+        self.isSpinning = NO;
+        [self.delegate dialController:self didSnapToString:self.selectedString];
+    }
+    else {
+        [self snap];
+    }
+}
+
+#pragma mark Custom getter
+
+- (NSInteger)selectedStringIndex {
+    return [self indexOfString:self.selectedString];
+}
+
+#pragma mark Helper methods
+
+//return the index of a string in the values
+- (NSInteger)indexOfString:(NSString *)string {
+    if (self.strings != nil) {
+        for (NSInteger i=0; i<[self.strings count]; i++) {
+            if ([(NSString *)[self.strings objectAtIndex:i] isEqualToString:string]) {
+                return i;
+            }
+        }
+    }
+    return -1;
+}
+
+@end