ios - CGContextDrawImage错误，如何分配缓冲区？

Question

我正在尝试将图像数据存储在我的应用程序的缓冲区中，以便我能够使用它，但是我在 CGContextDrawImage 行上收到 EXC_BAD_ACCESS 错误。 这是我正在使用的代码:

resizedImage.Array() // resizedImage - resized image of 280x140 pixels size
    func Array() {
        let dataBuffer = UnsafeMutablePointer<CUnsignedChar>.alloc(156800) //alloc(156800)
        memset(dataBuffer, 0, 156800)
        let colorSpace = CGColorSpaceCreateDeviceRGB()
        let bitmapInfo = CGBitmapInfo(rawValue: CGBitmapInfo.ByteOrder32Big.rawValue | CGImageAlphaInfo.PremultipliedLast.rawValue)
        let context = CGBitmapContextCreate(dataBuffer, 280, 140, 8, 156800, colorSpace, bitmapInfo.rawValue)
        let imageRef = CGImageCreateWithImageInRect(CGImage, CGRectMake(0, 0, 280, 140))
        let rectMake = CGRectMake(0, 0, 280, 140)
        CGContextDrawImage(context, rectMake, imageRef)

return
}

当尝试将缓冲区和字节设置为 null 和 0(如苹果文档中的自动内存分配应用程序)时，应用程序不会崩溃，但会出现以下错误:

Sep 17 17:18:33  VideoTester[4846] <Error>: CGBitmapContextCreate: invalid data bytes/row: should be at least 1120 for 8 integer bits/component, 3 components, kCGImageAlphaPremultipliedLast.
Sep 17 17:18:33  VideoTester[4846] <Error>: CGContextDrawImage: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.

好像我错过了一些东西，但无法真正弄清楚，需要任何建议，谢谢!

Answer 1

在peacer212的帮助下得到了这个工作，一切似乎都按需要工作，没有任何错误，这里是一个工作代码:

var dataBuffer = [UInt8](count: 280*140 * 4, repeatedValue: 0)

        let colorSpace = CGColorSpaceCreateDeviceRGB()
        let bitmapInfo = CGBitmapInfo(rawValue: CGBitmapInfo.ByteOrder32Big.rawValue | CGImageAlphaInfo.PremultipliedLast.rawValue)

        let context = CGBitmapContextCreate(&dataBuffer, 280, 140, 8, 1120, colorSpace, bitmapInfo.rawValue)
        let imageRef = CGImageCreateWithImageInRect(CGImage, CGRectMake(0, 0, 280, 140))
        let rectMake = CGRectMake(0, 0, 280, 140)

        CGContextDrawImage(context, rectMake, imageRef)