合成UIImageView，改变尺寸

#import "Masonry.h"
#import "QQChating.h"
#import "ContainImageView.h"
#import "ShowImageViewController.h"

@interface ShowImageViewController () <UIAlertViewDelegate>
{
    BOOL clicked;
}

@property (nonatomic, strong) UITextField* textField;
@property (nonatomic, strong) ContainImageView* imageView;

@property (nonatomic, copy) UIImage* tmpImage;

@end

@implementation ShowImageViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    clicked = NO;
    
    UIButton* button0 = [UIButton buttonWithType:UIButtonTypeCustom];
    [button0 setBackgroundColor:[UIColor redColor]];
    [button0 setTitle:@"0击" forState:UIControlStateNormal];
    [button0 addTarget:self action:@selector(buttonClicked:)
      forControlEvents:UIControlEventTouchUpInside];
    [button0 setTag:1000];
    button0.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:button0];
    
    UIButton* button1 = [UIButton buttonWithType:UIButtonTypeCustom];
    [button1 setBackgroundColor:[UIColor blueColor]];
    [button1 setTitle:@"1击" forState:UIControlStateNormal];
    [button1 addTarget:self action:@selector(buttonClicked:)
      forControlEvents:UIControlEventTouchUpInside];
    [button1 setTag:1001];
    button1.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:button1];
    
    UIButton* button2 = [UIButton buttonWithType:UIButtonTypeCustom];
    [button2 setBackgroundColor:[UIColor greenColor]];
    [button2 setTitle:@"2击" forState:UIControlStateNormal];
    [button2 addTarget:self action:@selector(buttonClicked:)
      forControlEvents:UIControlEventTouchUpInside];
    [button2 setTag:1002];
    button2.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:button2];
    
    UIButton* button3 = [UIButton buttonWithType:UIButtonTypeCustom];
    [button3 setBackgroundColor:[UIColor grayColor]];
    [button3 setTitle:@"3击" forState:UIControlStateNormal];
    [button3 addTarget:self action:@selector(buttonClicked:)
      forControlEvents:UIControlEventTouchUpInside];
    [button3 setTag:1003];
    button3.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:button3];
    
    UIView* superview = self.view;
    
    CGFloat padding = 10.0;
    
    [button0 mas_makeConstraints:^(MASConstraintMaker* make){
        
        make.centerY.mas_equalTo(superview);
        make.left.equalTo(superview).with.offset(padding);
        make.right.equalTo(button1.mas_left).with.offset(-padding);
        make.height.mas_equalTo(@50);
        make.width.equalTo(@[button1, button2, button3]);
        
    }];
    
    [button1 mas_makeConstraints:^(MASConstraintMaker* make){
        
        make.centerY.mas_equalTo(superview);
        make.right.mas_equalTo(button2.mas_left).with.offset(-padding);
        make.height.mas_equalTo(button0);
        make.width.equalTo(@[button0, button2, button3]);
        
    }];
    
    [button2 mas_makeConstraints:^(MASConstraintMaker* make){
        
        make.centerY.mas_equalTo(superview);
        make.height.mas_equalTo(button0);
        make.width.equalTo(@[button0, button1, button3]);
        
    }];
    
    [button3 mas_makeConstraints:^(MASConstraintMaker* make){
        
        make.centerY.mas_equalTo(superview);
        make.height.mas_equalTo(button0);
        make.left.equalTo(button2.mas_right).with.offset(padding);
        make.right.equalTo(superview).with.offset(-padding);
        make.height.mas_equalTo(button0);
        make.width.equalTo(@[button0, button1, button2]);
        
    }];

    self.imageView = [ContainImageView new];
    self.imageView.translatesAutoresizingMaskIntoConstraints = NO;
    [self.imageView setImage:[UIImage imageNamed:@"icon.png"]];
    [superview addSubview:self.imageView];
    
    [self.imageView mas_makeConstraints:^(MASConstraintMaker* make){
    
        make.width.mas_equalTo(@100);
        make.height.mas_equalTo(@100);
        make.centerX.mas_equalTo(superview);
        make.top.equalTo(superview).with.offset(10*padding);
        
    }];
    
    
    self.textField = [UITextField new];
    self.textField.translatesAutoresizingMaskIntoConstraints = NO;
    self.textField.borderStyle = UITextBorderStyleLine;
    self.textField.placeholder = @"input the size";
    self.textField.keyboardType = UIKeyboardTypeNumberPad;
    self.textField.textAlignment = NSTextAlignmentCenter;
    [superview addSubview:self.textField];
    
    [self.textField mas_makeConstraints:^(MASConstraintMaker* make){
    
        make.width.mas_equalTo(@150);
        make.height.mas_equalTo(@35);
        make.centerX.mas_equalTo(superview);
        make.bottom.equalTo(superview).with.offset(-160);
    
    }];
    
    
    self.tmpImage = [UIImage new];
    
}

//输入后，上下滑动屏幕可以自动改变
- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    
    UISwipeGestureRecognizer* updown = [[UISwipeGestureRecognizer alloc] initWithTarget:self
                                                                                 action:@selector(updown)];
    [updown setDirection:UISwipeGestureRecognizerDirectionUp | UISwipeGestureRecognizerDirectionDown];
    [self.view addGestureRecognizer:updown];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
    
}

- (void)updown
{
    [self.textField resignFirstResponder];
    
    if (clicked == NO)
    {
        UIAlertView* alert = [[UIAlertView alloc] initWithTitle:nil
                                                        message:@"先添加角标！"
                                                       delegate:nil
                                              cancelButtonTitle:@"确定"
                                              otherButtonTitles:nil, nil];
        [alert show];
        return;
    }
    
    if ([self.textField.text isEqualToString:@""] || [self.textField.text length] == 0 || self.textField.text == NULL)
    {
        UIAlertView* alert = [[UIAlertView alloc] initWithTitle:nil
                                                        message:@"大小不能空！"
                                                       delegate:nil
                                              cancelButtonTitle:@"确定"
                                              otherButtonTitles:nil, nil];
        [alert show];
        return;
    }

    //用一个self.tmpImage来充当 [UIImage imageNamed:@"icon.png"]
    //这种“常量”的中间temp值，这样既可以模糊化又可以清晰化
    UIImage* image = [self.tmpImage copy];
    
    image = [self imageWithImage:image scaledToSize:CGSizeMake([self.textField.text floatValue],
                                                                [self.textField.text floatValue])];
    
    [self.imageView setImage:image];
    
}

//改变尺寸的方法:
- (UIImage*)imageWithImage:(UIImage*)image
                            scaledToSize:(CGSize)newSize;
{
    UIGraphicsBeginImageContext( newSize );
    [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    //这一步很关键，合成图像之后是不会改变当前的UIImageView的结构的
    //所以需要在这里把之前添加的subviews删除掉
    for (id subviews in self.imageView.subviews)
    {
        [((UIView*)subviews) removeFromSuperview];
    }
    
    return newImage;
}

//截屏方法1:
- (UIImage *)snapshot
{
    UIGraphicsBeginImageContextWithOptions(self.imageView.bounds.size, YES, 0);
    [self.imageView drawViewHierarchyInRect:self.imageView.bounds afterScreenUpdates:YES];
    UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return image;
}

//实现方法2:
//- (UIImage* )snapshot
//{
//    UIImage* snapshot = nil;
//    
//    UIGraphicsBeginImageContext(self.imageView.frame.size);
//    {
//        [self.imageView.layer renderInContext:UIGraphicsGetCurrentContext()];
//        snapshot = UIGraphicsGetImageFromCurrentImageContext();
//    }
//    
//    UIGraphicsEndImageContext();
//    
//    return snapshot;
//}

#pragma mark - ButtonClicked:

- (void)changeImageViewSize:(id)sender
{
    NSLog(@"11");
}

- (void)buttonClicked:(UIButton*)button
{
    switch (button.tag)
    {
        case 1000:
        {
            [self.imageView addIconWithImage:[UIImage imageNamed:@"512-橙色右上.png"] andTag:RIGHT_TOP];
            
            break;
        }
            
        case 1001:
        {
            [self.imageView addIconWithImage:[UIImage imageNamed:@"512-橙色右下.png"] andTag:RIGHT_DOWN];
            
            break;
        }
            
        case 1002:
        {
            [self.imageView addIconWithImage:[UIImage imageNamed:@"512-橙色左上.png"] andTag:LEFT_TOP];

            break;
        }
            
        case 1003:
        {
            [self.imageView addIconWithImage:[UIImage imageNamed:@"512-橙色左下.png"] andTag:LEFT_DOWN];

            break;
        }
            
        default:
            break;
    }
    
    //拿一个tmpImage来存添加角标后的原始值，但是不是万能的，因为如果你同时添加多个角标，那就乱定了！
    self.tmpImage = [self snapshot];
    clicked = YES;
}

#pragma mark - Orientation Change:

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
    BOOL isLandscape = NO;
    UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
    
    isLandscape = ((orientation==UIInterfaceOrientationLandscapeRight)||(orientation==UIInterfaceOrientationLandscapeLeft));
    
    if(isLandscape)
    {
        //横屏
        [super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
        
        [self.imageView mas_updateConstraints:^(MASConstraintMaker* make){
            
            make.top.equalTo(self.view).with.offset(10);
            
        }];
        
        
        [self.textField mas_updateConstraints:^(MASConstraintMaker* make){
            
            make.bottom.equalTo(self.view).with.offset(-70);
            
        }];
    }
    else
    {                
        //纵屏
        [super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
        
        [self.imageView mas_updateConstraints:^(MASConstraintMaker* make){
            
            make.top.equalTo(self.view).with.offset(100);
            
        }];
        
        [self.textField mas_updateConstraints:^(MASConstraintMaker* make){
            
            make.bottom.equalTo(self.view).with.offset(-160);
            
        }];
    }

}

@end