UIButton 控制UIImage自由改变大小

1.0 使用

UIButton *btn = [UIButton alloc] init];
[btn setContentMode:UIViewContentModeScaleAspectFit];
 
UIImage *selectedImage = [UIImage imageNamed:@"heart_highlighted.png"];

[btn setImage:[selectedImage
 transformWidth:90 height:125] forState:UIControlStateSelected];
//设置内容垂直或水平显示位置
 
[btn setContentHorizontalAlignment:UIControlContentHorizontalAlignmentCenter];
[btn setContentVerticalAlignment:UIControlContentVerticalAlignmentTop];

 

//

//  UIImageCategory.m

//  CategorySample

//

//  Created by yile on 3/29/09.

//  Copyright 2009 Quoord. All rights reserved.

//

#import <UIKit/UIKit.h>

@interface UIImage (Category)

- (UIImage *)transformWidth:(CGFloat)width height:(CGFloat)height;

@end

#import "UIImageCategory.h"

@implementation UIImage (Category)

// --------------------------------------------------

// Resize an image

// --------------------------------------------------

- (UIImage*)transformWidth:(CGFloat)width 

height:(CGFloat)height {

 

CGFloat destW = width;

CGFloat destH = height;

CGFloat sourceW = width;

CGFloat sourceH = height;

 

CGImageRef imageRef = self.CGImage;

CGContextRef bitmap = CGBitmapContextCreate(NULL, 

destW, 

destH,

CGImageGetBitsPerComponent(imageRef), 

4*destW, 

CGImageGetColorSpace(imageRef),

(kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst));

 

CGContextDrawImage(bitmap, CGRectMake(0, 0, sourceW, sourceH), imageRef);

 

CGImageRef ref = CGBitmapContextCreateImage(bitmap);

UIImage *resultImage = [UIImage imageWithCGImage:ref];

CGContextRelease(bitmap);

CGImageRelease(ref);

 

return resultImage;

}

@end