Objective-C ,ios,iphone开发基础:快速实现一个简单的图片查看器

新建一个single view 工程：



关闭ARC , 在.xib视图文件上拖放一个UIImageView 两个UIButton ，一个UISlider ，布局如图。



并为他们连线，

UIImageView 和 UISlider 分别定义插座变量，两个 UIButton 分别 连接两个Action next和previous ，在为 UISlider 连接一个Action 事件。



再在.h 文件中声明两个实例变量。 NSInteger index ; NSMutableArray* arrayPic ; 一个用来记录当前图片的index，一个用来做图片的容器，

用UISlider 来控制图片的透明度 （alpha 属性）。在slider 的界面构建起动作中添加代码，让图片的透明度等于 slider的value。

- (IBAction)sliderChangeValued:(id)sender {

self.imageView.alpha = slider.value;
}

在两个UIButton 的界面构建起动作中添加代码，循环遍历arrayPic中的图片：

- (IBAction)next:(id)sender {
if(index == [arrayPic count]){
index = 0;
}
self.imageView.image = [UIImage imageWithContentsOfFile:[arrayPic objectAtIndex:index]];
index++;
}

- (IBAction)previous:(id)sender {
if(index == -1){
index = ([arrayPic count] -1);
}
self.imageView.image = [UIImage imageWithContentsOfFile:[arrayPic objectAtIndex:index]];
index--;
}

至此：简单的图片查看器已经完成，



整个控制器类中的代码：

//
//  wsqViewController.h
//  picLook
//
//  Created by administrator on 13-9-5.
//  Copyright (c) 2013年 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface wsqViewController : UIViewController {
UIImageView *imageView;
UISlider *slider;
NSInteger index ;
NSMutableArray* arrayPic ;

}

@property (retain, nonatomic) IBOutlet UIImageView *imageView;
@property (retain, nonatomic) IBOutlet UISlider *slider;
- (IBAction)sliderChangeValued:(id)sender;
- (IBAction)next:(id)sender;

- (IBAction)previous:(id)sender;

@end

//
//  wsqViewController.m
//  picLook
//
//  Created by administrator on 13-9-5.
//  Copyright (c) 2013年 __MyCompanyName__. All rights reserved.
//

#import "wsqViewController.h"

@implementation wsqViewController
@synthesize imageView;
@synthesize slider;

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
[super viewDidLoad];
//获取mainbudle下所有 jpg格式的图片，
arrayPic = [[NSMutableArray alloc ] initWithArray: [[NSBundle mainBundle] pathsForResourcesOfType:@"jpg" inDirectory:nil]];
index = 0;
NSLog(@"%@",arrayPic);

}

- (void)viewDidUnload
{
[self setImageView:nil];
[self setSlider:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}

- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

- (void)dealloc {
[arrayPic release];
[imageView release];
[slider release];
[super dealloc];
}
- (IBAction)sliderChangeValued:(id)sender {

self.imageView.alpha = slider.value;
}

- (IBAction)next:(id)sender {
if(index == [arrayPic count]){
index = 0;
}
self.imageView.image = [UIImage imageWithContentsOfFile:[arrayPic objectAtIndex:index]];
index++;
}

- (IBAction)previous:(id)sender {
if(index == -1){
index = ([arrayPic count] -1);
}
self.imageView.image = [UIImage imageWithContentsOfFile:[arrayPic objectAtIndex:index]];
index--;
}
@end