循环播放一系列图像

[英]Looping through an array of images

本文翻译自 Muhammad Ameen Sheikh 查看原文 2014/12/13 585 objective-c/ ios

I want to loop through an array of images and display each image one by one on the click of a single button.

我想循环浏览一系列图像,并通过单击一个按钮逐个显示每个图像。

Here is my code.

这是我的代码。

This is in the viewDidLoad method:

这是在viewDidLoad方法中:

    arrayImg = [[NSArray alloc]initWithObjects:
            [UIImage imageNamed:@"samsung_logo_small.jpg"],
            [UIImage imageNamed:@"Small_logo_splash.png"],
            [UIImage imageNamed:@"Red_logos_small.png"],
            [UIImage imageNamed:@"li-logo-small-drshdw.gif"],
            nil];

Here is my button in which I am looping through the images

这是我的按钮,我循环浏览图像

- (IBAction)btn:(id)sender {
for (int i = 0 ; i < [arrayImg count]; i++) {
    [img setImage:[arrayImg objectAtIndex:i]];
}

}

The problem is that it is only showing the last image, not all of the images.

问题是它只显示最后一张图像,而不是所有图像。

What I am doing wrong here?

我在这做错了什么?

I found 2 questions like this on but could not find the answer.

我发现了2个这样的问题,但找不到答案。

4 个解决方案

#1

Add following to YourClass.m file:

将以下内容添加到YourClass.m文件中:

@interface YourClass() {
    int variableName;
}

@end

in viewDidLoad initialize variableName to 0.

在viewDidLoad中将variableName初始化为0。

- (IBAction)btn:(id)sender 
{
    if (variableName == arrayImg.count)
    {
        variableName = 0;
    }
    [img setImage:[arrayImg objectAtIndex:classVariable]];
    variableName++
}

#2

If you want to show one image at a time then why loop? You can do it like this:

如果你想一次显示一个图像,那么为什么要循环?你可以这样做:

 static int index;

- (IBAction)btn:(id)sender {

  [img setImage:[arrayImg objectAtIndex:index]];
   index = index == arrayImg.count - 1 ? 0 : index + 1;
}

#3

In your viewDidLoad, add one more line:

在viewDidLoad中,再添加一行:

[buttonName setTag:0];

Here change in btn event:

这里改变了btn事件:

- (IBAction)btn:(UIButton *)sender {

   [img setImage: [arrayImg objectAtIndex: [sender tag]]];

   [sender setTag: [sender tag]+1];

   if ([sender tag] > [arrayImg count]) {
     [sender setTag: 0];
   }
}

This will help you in memory management as well, because here no other extra flag variable required to hold your integer value, whereas your UIButton object only will hold.

这也可以帮助你进行内存管理,因为这里没有其他额外的标志变量来保存你的整数值,而你的UIButton对象只能保存。

Hope this will help you to achieve your requirement.

希望这能帮助您实现您的要求。

#4

From what I can tell, you're looping through all of the images on a single click.

据我所知,您只需单击一下即可遍历所有图像。

A better approach might be to display an image after a click but instead of looping just increment a variable that represents your index value by 1. This way after each click the next image is displayed.

更好的方法可能是在单击后显示图像,而不是循环只是将表示索引值的变量增加1.这样每次单击后,将显示下一个图像。

The other approach would be to use a timer.

另一种方法是使用计时器。

[NSTimer scheduledTimerWithTimeInterval:2.0
                                 target:self
                               selector:@selector(displayNextImage:)
                               userInfo:nil
                                repeats:YES];

智能推荐

注意！

本站翻译的文章，版权归属于本站，未经许可禁止转摘，转摘请注明本文地址：http://www.silva-art.net/blog/2014/12/13/3c4f38dcb565cfc62c473a9f82878138.html。

猜您在找

即使通过一系列图像预先加载也表现不佳 - Poor performance even through array of images is preloaded Javascript - 循环遍历一系列有效的URL - Javascript - Looping through an array of valid URL's 如何获得一系列图像？ - How to get an array of images? 使用迭代和数组动画一系列图像 - animating a series of images using iteration and array 循环遍历字符串数组（迭代图像） - Looping through array of strings (iterating images)

智能推荐