ios开发图片上传,ios传图片到安卓

iOS 开发中的图片压缩

在项目中经常遇到要上传图片，如果直接上传，那么会上传比较大的图片，导致费流量，刷新时加载图片时间过长，手机内存占用率高等问题。

创新互联专业为企业提供让胡路网站建设、让胡路做网站、让胡路网站设计、让胡路网站制作等企业网站建设、网页设计与制作、让胡路企业网站模板建站服务，10余年让胡路做网站经验，不只是建网站，更提供有价值的思路和整体网络服务。

一、先来介绍下概念：

图片的压缩其实是俩概念，

1、是 “压” 文件体积变小，但是像素数不变，长宽尺寸不变，那么质量可能下降，

2、是 “缩” 文件的尺寸变小，也就是像素数减少。长宽尺寸变小，文件体积同样会减小。

二、解决方法（以上传头像为例），先缩再压：

2.1 矫正图片方向（照片是有方向的，避免出现“倒立”的情况）

- (UIImage*)fixOrientation:(UIImage*)aImage {

// No-op if the orientation is already correct

if(aImage.imageOrientation==UIImageOrientationUp)

returnaImage;

// We need to calculate the proper transformation to make the image upright.

// We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.

CGAffineTransformtransform =CGAffineTransformIdentity;

switch(aImage.imageOrientation) {

caseUIImageOrientationDown:

caseUIImageOrientationDownMirrored:

transform =CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);

transform =CGAffineTransformRotate(transform,M_PI);

break;

caseUIImageOrientationLeft:

caseUIImageOrientationLeftMirrored:

transform =CGAffineTransformTranslate(transform, aImage.size.width,0);

transform =CGAffineTransformRotate(transform,M_PI_2);

break;

caseUIImageOrientationRight:

caseUIImageOrientationRightMirrored:

transform =CGAffineTransformTranslate(transform,0, aImage.size.height);

transform =CGAffineTransformRotate(transform, -M_PI_2);

break;

default:

break;

}

switch(aImage.imageOrientation) {

caseUIImageOrientationUpMirrored:

caseUIImageOrientationDownMirrored:

transform =CGAffineTransformTranslate(transform, aImage.size.width,0);

transform =CGAffineTransformScale(transform, -1,1);

break;

caseUIImageOrientationLeftMirrored:

caseUIImageOrientationRightMirrored:

transform =CGAffineTransformTranslate(transform, aImage.size.height,0);

transform =CGAffineTransformScale(transform, -1,1);

break;

default:

break;

}

// Now we draw the underlying CGImage into a new context, applying the transform

// calculated above.

CGContextRefctx =CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height,

CGImageGetBitsPerComponent(aImage.CGImage),0,

CGImageGetColorSpace(aImage.CGImage),

CGImageGetBitmapInfo(aImage.CGImage));

CGContextConcatCTM(ctx, transform);

switch(aImage.imageOrientation) {

caseUIImageOrientationLeft:

caseUIImageOrientationLeftMirrored:

caseUIImageOrientationRight:

caseUIImageOrientationRightMirrored:

CGContextDrawImage(ctx,CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage);

break;

default:

CGContextDrawImage(ctx,CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.CGImage);

break;

}

CGImageRef cgimg =CGBitmapContextCreateImage(ctx);

UIImage *img = [UIImageimageWithCGImage:cgimg];

CGContextRelease(ctx);

CGImageRelease(cgimg);

return img;

}

2.2 拿到上面矫正过的图片，缩小图片尺寸，调用下面方法传入newSize，如（200，200）：

+ (UIImage*)imageWithImageSimple:(UIImage*)image scaledToSize:(CGSize)newSize

{

UIGraphicsBeginImageContext(newSize);

[imagedrawInRect:CGRectMake(0,0,newSize.width,newSize.height)];

UIImage* newImage =UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return newImage;

}

2.3 将2.2的图片再压，这个方法可以重复压

//调整大小

NSData *imageData =UIImageJPEGRepresentation(newImage,rate);

NSUIntegersizeOrigin = [image Datalength];//多少KB

NSUIntegersizeOriginKB = sizeOrigin /1024;//多少KB

2.4 上传头像

调用后台接口，把imageData二进制数据上传即可

总结：对图片压缩处理时，在保证图片清晰度变化不大时，减小图片文件大小。方法2.2中的newSize 和 2.3中的rate要以实际效果来设置，我在自己项目中上传的头像最终尺寸是200*200像素，大小为4KB左右。

IOS开发，上传完图片后，怎么获取图片的URL

移动端在图片上传完成后可以让服务端将上传成功的图片的url返回给你

iOS上传图片大小保持在1M以内

实际开发过程中很有可能会遇到一些比较麻烦的需求:这里就分享下上传图片的时候限制上传的图片的大小的问题,调用系统相册以及调用照相机的实现我就不详细说了,这里主要说一下压缩图片至1M以内的实现,顺带着将file进行base64转码的方法说一下,以下进入主题:

// 选中照片之后的回调方法

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary*)info

{

// 先dismiss调选取照片的VC,在completion block里面完成以下几个操作:

[self dismissViewControllerAnimated:YES completion:^{

UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];

// 拍照存入相册

if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {

UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);

}

// 判断哪个视图需要照片

UIImage *tempImage = nil;

NSString *imageName = nil;

// 这里注意下:如果有多个上传图片的选项,可以给每个选项设置一个类型,然后每个选项根据相应的类型来设置不同的imageName即可.暂时我只设置一个值,如@"test.jpeg".

imageName = @"test.jpeg";

// 这里:如果有多个上传图片的选项,且给每个选项设置一个类型,这时就可以根据imageName的值的不同,写入本地之后返回的image值也就不同..

// 将返回的本地的图片赋值给tempImage

tempImage = [self writeToCachesWithImage:image imageName:imageName];

// 下面就是调用你自己的上传图片的网络请求了,这是我的网络请求封装的方法....

[self uploadImageWithImage:tempImage imageName:imageName];

}];

}

// 把上传需要的图片转为字符串

- (NSData *)stringWithImage:(UIImage *)image imageName:(NSString *)imageName

{

NSString *imagePath = [[self postImagePathWithFileName:certificationFileName] stringByAppendingPathComponent:imageName];

NSData *imageData = nil;

CGFloat mb = 1.0; // 1MB

CGFloat uploadMB = 1.0; // 1M

CGFloat itemMB = 0; // 把文件转成MB

if ([[NSFileManager defaultManager] fileExistsAtPath:imagePath]) {

long long imageSize = [[[NSFileManager defaultManager] attributesOfItemAtPath:imagePath error:nil] fileSize];

itemMB = imageSize / (mb * 1024 * 1024) ;

} else {

CGImageRef cgImageRef = image.CGImage;

size_t bpp = CGImageGetBitsPerPixel(cgImageRef);

size_t bpc = CGImageGetBitsPerComponent(cgImageRef);

size_t bytes_per_pixel = bpp / bpc;

CGFloat lPixelsPerMB = mb / bytes_per_pixel;

CGFloat totalPixel = CGImageGetWidth(cgImageRef) * CGImageGetHeight(cgImageRef);

itemMB = totalPixel / lPixelsPerMB;

}

if (itemMB = uploadMB) {

imageData = UIImageJPEGRepresentation(image, 1.0f);

} else {

// 大于1M压到1M

CGSize imageSize = image.size;

CGSize toImageSize = CGSizeZero;

if (imageSize.width imageSize.height) {

toImageSize = CGSizeMake(1024, 1024 * imageSize.height / imageSize.width);

} else if (imageSize.width imageSize.height) {

toImageSize = CGSizeMake(1024 * imageSize.width / imageSize.height, 1024);

} else {

toImageSize = CGSizeMake(sqrt(1048576), sqrt(1048576));

}

UIImage *toImage = [image imageCompressForSize:image targetSize:toImageSize];

imageData = UIImageJPEGRepresentation(toImage, 1.f);

}

// 这里注意下:根据你们自己的需要转成不同类型的NSData字节流...

// 这是不用base64转码返回的string

return imageData;

// 这是用base64转码返回的string,1.0上传的方式

//    Byte *byte = (Byte *)[imageData bytes];

//    return [NSString stringWithFormat:@"jpeg@%@", [GTMBase64 stringByEncodingBytes:byte length:imageData.length]];

}

/* 上传的图片所在的沙盒文件夹

* @param : fileName 文件的名称.

* @param : return 文件的存储路径

*/

- (NSString *)postImagePathWithFileName:(NSString *)fileName

{

NSString *imagePath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:fileName];

if (![[NSFileManager defaultManager] fileExistsAtPath:imagePath]) {

[[NSFileManager defaultManager] createDirectoryAtPath:imagePath withIntermediateDirectories:YES attributes:nil error:nil];

}

return imagePath;

}

/*

* 把图片存入本地并返回

* @param : image 选中的image

* @param : imageName 图片的名称

* @return : UIImage

*/

- (UIImage *)writeToCachesWithImage:(UIImage *)image imageName:(NSString *)imageName

{

NSString *imagePath = [[self postImagePathWithFileName:certificationFileName] stringByAppendingPathComponent:imageName];

BOOL isResult = [UIImageJPEGRepresentation(image, 1.0f) writeToFile:imagePath atomically:YES];

if (isResult) {

// 写入成功，把图片取出来

UIImage *certificationImage = [UIImage imageWithContentsOfFile:imagePath];

return certificationImage;

} else {

// 写入失败，直接返回原始图片

return image;

}

}