字节自千字节

发布于 2024-10-02 22:45:50 字数 872 浏览 2 评论 0原文

我正在检索文档目录中所有文件的大小。我正在使用方法 attributesOfItemAtPath 来执行此操作。它是成功的。但我得到的是字节形式和类 NSNumber 的输出。看起来不太好。

因此，我需要获取以 KB 或 MB 为单位的输出，并且必须将它们转换为 NSString 以便将其存储在 NSDictionary 中，因为我必须将其显示在表视图。请帮助我这样做。谢谢。

这是我的代码..

directoryContent = [[NSMutableArray alloc] init];
    for (NSString *path in paths){
filesDictionary  =[[NSMutableDictionary alloc] init];
filesSize = [[NSNumber alloc] init]; 
filesSize = [filesDictionary objectForKey:NSFileSize];
filesDictionary = [NSDictionary dictionaryWithObjectsAndKeys:filesSize, @"filesSize", nil];
[directoryContent addObject:[filesDictionary copy]];
}

我使用以下代码来绑定 tableView 中的大小，但该代码不起作用。

cell.lblSize.text = (NSString *) [[directoryContent objectAtIndex:listIndex] objectForKey:@"filesSize"];

帮助我将文件的大小从字节转换为千字节并将其显示在表视图中。先感谢您..

原文

I am retrieving the size of all files in the document directory. I am using the method attributesOfItemAtPath to do so. It is successful. But I am getting the output in the form of bytes and of class NSNumber. It does'nt look good.

So, I need to get the output in KBs or MBs and I have to convert them into NSString in order to store that in a NSDictionary as I have to display it in a TableView. Please help me to do so. Thank you.

Here is my code..

directoryContent = [[NSMutableArray alloc] init];
    for (NSString *path in paths){
filesDictionary  =[[NSMutableDictionary alloc] init];
filesSize = [[NSNumber alloc] init]; 
filesSize = [filesDictionary objectForKey:NSFileSize];
filesDictionary = [NSDictionary dictionaryWithObjectsAndKeys:filesSize, @"filesSize", nil];
[directoryContent addObject:[filesDictionary copy]];
}

And I am using the following code to bind the size in tableView which is not working.

cell.lblSize.text = (NSString *) [[directoryContent objectAtIndex:listIndex] objectForKey:@"filesSize"];

Help me to convert the size of a file from byte to KiloByte and to display it in a tableView.
Thank you in advance..

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薄暮涼年 2024-10-09 22:45:50

如果您愿意，可以使用我的 NSValueTransformer 子类：

@interface FileSizeTransformer : NSValueTransformer {

}

+ (Class)transformedValueClass;
+ (BOOL)allowsReverseTransformation;
- (id)transformedValue:(id)value;

@end

@implementation FileSizeTransformer
+ (Class)transformedValueClass;
{
    return [NSString class];
}

+ (BOOL)allowsReverseTransformation;
{
    return NO;
}
- (id)transformedValue:(id)value;
{
    if (![value isKindOfClass:[NSNumber class]])
        return nil;

    double convertedValue = [value doubleValue];
    int multiplyFactor = 0;

    NSArray *tokens = [NSArray arrayWithObjects:@"B",@"KB",@"MB",@"GB",@"TB",nil];

    while (convertedValue > 1024) {
        convertedValue /= 1024;
        multiplyFactor++;
    }

    return [NSString stringWithFormat:@"%4.2f %@",convertedValue, [tokens objectAtIndex:multiplyFactor],value];
}

@end

You can use my NSValueTransformer subclass if you like:

@interface FileSizeTransformer : NSValueTransformer {

}

+ (Class)transformedValueClass;
+ (BOOL)allowsReverseTransformation;
- (id)transformedValue:(id)value;

@end

@implementation FileSizeTransformer
+ (Class)transformedValueClass;
{
    return [NSString class];
}

+ (BOOL)allowsReverseTransformation;
{
    return NO;
}
- (id)transformedValue:(id)value;
{
    if (![value isKindOfClass:[NSNumber class]])
        return nil;

    double convertedValue = [value doubleValue];
    int multiplyFactor = 0;

    NSArray *tokens = [NSArray arrayWithObjects:@"B",@"KB",@"MB",@"GB",@"TB",nil];

    while (convertedValue > 1024) {
        convertedValue /= 1024;
        multiplyFactor++;
    }

    return [NSString stringWithFormat:@"%4.2f %@",convertedValue, [tokens objectAtIndex:multiplyFactor],value];
}

@end

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信愁 2024-10-09 22:45:50

四舍五入到最接近的 KB：

NSNumber *fileSize = [[directoryContent objectAtIndex:listIndex]
                      objectForKey:@"fileSize"];
cell.lblSize.text = [NSString stringWithFormat: @"%d",
                     (int)round([fileSize doubleValue] / 1024]);

Rounded to the nearest KB:

NSNumber *fileSize = [[directoryContent objectAtIndex:listIndex]
                      objectForKey:@"fileSize"];
cell.lblSize.text = [NSString stringWithFormat: @"%d",
                     (int)round([fileSize doubleValue] / 1024]);

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