ios 对图像不变形的处理

// 2，  stretchableImageWithLeftCapWidth拉伸不变形

UIImage*image=[[UIImageimageNamed:@"leader1"]stretchableImageWithLeftCapWidth:10topCapHeight:10];

//1， 初始化一个imageview

UIImageView*imageView=[[UIImageViewalloc]initWithImage:image];

//3，等比率缩放

[selfscaleImage:imageView.imagetoScale:1/8];

imageView.frame=CGRectMake(10,nameTextField.bottom,ScreenWidth-20,headVIew.height-nameTextField.bottom);

[headVIewaddSubview:imageView];

//1.等比率缩放

- (UIImage*)scaleImage:(UIImage*)image toScale:(float)scaleSize

{

UIGraphicsBeginImageContext(CGSizeMake(image.size.width* scaleSize, image.size.height* scaleSize));

[imagedrawInRect:CGRectMake(0,0, image.size.width* scaleSize, image.size.height* scaleSize)];

UIImage*scaledImage =UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

returnscaledImage;

}

#pragma mark ----图片剪切到指定大小

- (UIImage*)cutImage:(UIImage*)image viewsize:(CGSize)viewsize

{

//压缩图片

CGSizenewSize;

CGImageRefimageRef =nil;

if((image.size.width/ image.size.height) < (viewsize.width/ viewsize.height)) {

newSize.width= image.size.width;

newSize.height= image.size.width* viewsize.height/ viewsize.width;

imageRef =CGImageCreateWithImageInRect([imageCGImage],CGRectMake(0,fabs(image.size.height- newSize.height) /2, newSize.width, newSize.height));

}else{

newSize.height= image.size.height;

newSize.width= image.size.height* viewsize.width/ viewsize.height;

imageRef =CGImageCreateWithImageInRect([imageCGImage],CGRectMake(fabs(image.size.width- newSize.width) /2,0, newSize.width, newSize.height));

}

return[UIImageimageWithCGImage:imageRef];

}

#pragma mark ----图片压缩到指定大小

- (UIImage*)scaleToSize:(UIImage*)img size:(CGSize)size

{

//创建一个bitmap的context,并把它设置成为当前正在使用的context

UIGraphicsBeginImageContext(size);

//绘制改变大小的图片

[imgdrawInRect:CGRectMake(0,0, size.width, size.height)];

//从当前context中创建一个改变大小后的图片

UIImage* scaledImage =UIGraphicsGetImageFromCurrentImageContext();

//使当前的context出堆栈

UIGraphicsEndImageContext();

//返回新的改变大小后的图片

returnscaledImage;

}