NSURLConnection 下载大文件 (40MB)

使用NSURLConnection下载大文件的案例代码

objc
#import "ViewController.h"
@interface ViewController () 
@property (nonatomic, strong) NSURLConnection *connection;
@property (nonatomic, strong) NSFileHandle *fileHandle;
@end
@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
    
    NSURL *fileURL = [NSURL URLWithString:@"https://example.com/largefile.zip"];
    NSURLRequest *request = [NSURLRequest requestWithURL:fileURL];
    
    self.connection = [NSURLConnection connectionWithRequest:request delegate:self];
    
    // 创建一个用于保存文件的临时文件
    NSString *tempFilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"tempfile"];
    [[NSFileManager defaultManager] createFileAtPath:tempFilePath contents:nil attributes:nil];
    self.fileHandle = [NSFileHandle fileHandleForWritingAtPath:tempFilePath];
}
#pragma mark - NSURLConnectionDelegate
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    // 获取文件总大小等信息
    long long fileSize = response.expectedContentLength;
    
    // 移动文件指针到文件末尾
    [self.fileHandle seekToEndOfFile];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    // 将数据写入文件
    [self.fileHandle writeData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    // 下载完成后的处理
    [self.fileHandle closeFile];
    
    // 将临时文件移动到目标文件
    NSString *tempFilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"tempfile"];
    NSString *targetFilePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/largefile.zip"];
    [[NSFileManager defaultManager] moveItemAtPath:tempFilePath toPath:targetFilePath error:nil];
}
@end