writeToFile如何判断它何时完成

Question

我正在做一些数据写入我的文档目录,我想知道是否有办法告诉我的writeToFile方法何时完成,我创建的文件是否已完全创建.在此先感谢这里是我正在调用的方法我正在寻找一种方式,它是委托方法或其他方式告诉它何时完成.

[imageData writeToFile:fullPathToFile atomically:YES];

缺口

Answer 1

该方法writeToFile:atomically是"同步的".它将写入文件然后返回YES或NO取决于文件是否成功写入.

这意味着一旦方法返回,操作就完成了.

BOOL success = [imageData writeToFile:fullPathToFile atomically:YES];
// Now, the operation is complete
// success indicates whether the file was successfully written or not

Answer 2

斯威夫特5：

do {
    try data.write(to: path)
    // here's when write operation is completed without errors thrown
} catch {
    Swift.print(error)
}