UIImage相关

设置尺寸

imageView.frame = CGRectMake(0, 0, 100, 100);

设置图片资源

• 方式一

/**
加载Assets.xcassets这里面的图片:
    1> 打包后变成Assets.car
    2> 拿不到路径
    3> 只能通过imageNamed:来加载图片
    4> 不能通过imageWithContentsOfFile:来加载图片
*/
imageView.image = [UIImage imageNamed:@"1"];

• 方式二

/**
放到项目中的图片:
    1> 可以拿到路径
    2> 能通过imageNamed:来加载图片
    3> 也能通过imageWithContentsOfFile:来加载图片
*/
NSString *path = [[NSBundle mainBundle] pathForResource:@"1" ofType:@"png"];
imageView.image = [UIImage imageWithContentsOfFile:path];

设置图片的内容模式

/**
    UIViewContentModeScaleToFill,
    UIViewContentModeScaleAspectFit,      // contents scaled to fit with fixed aspect. remainder is transparent
    UIViewContentModeScaleAspectFill,     // contents scaled to fill with fixed aspect. some portion of content may be clipped.
    UIViewContentModeRedraw,              // redraw on bounds change (calls -setNeedsDisplay)
    UIViewContentModeCenter,              // contents remain same size. positioned adjusted.
    UIViewContentModeTop,
    UIViewContentModeBottom,
    UIViewContentModeLeft,
    UIViewContentModeRight,
    UIViewContentModeTopLeft,
    UIViewContentModeTopRight,
    UIViewContentModeBottomLeft,
    UIViewContentModeBottomRight,
*/
imageView.contentMode = UIViewContentModeScaleAspectFill;

裁剪多余的部分

imageView.clipsToBounds = YES;

设置frame的方式

• 方式一

UIImageView *imageView = [[UIImageView alloc] init];
imageView.image = [UIImage imageNamed:@"1"];
imageView.frame = CGRectMake(100, 100, 267, 400);
imageView.frame = (CGRect){{100, 100},{267, 400}};

• 方式二

UIImageView *imageView = [[UIImageView alloc] init];
// 创建一个UIImage对象
UIImage *image = [UIImage imageNamed:@"1"];
// 设置frame
imageView.frame = CGRectMake(100, 10, image.size.width, image.size.height);
// 设置图片
imageView.image = image;

• 方式三

UIImage *image = [UIImage imageNamed:@"1"];
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 10, image.size.width, image.size.height)];
imageView.image = image;

• 方式四

// 创建一个UIimageview对象
// 注意: initWithImage 默认就有尺寸--->图片的尺寸
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"1"]];

创建帧动画

NSMutableArray<UIImage *> *imageArr = [NSMutableArray array];
for (int i=0; i<20; i++) {
    // 获取图片的名称
    NSString *imageName = [NSString stringWithFormat:@"%d", i+1];
    // 创建UIImage对象
    UIImage *image = [UIImage imageNamed:imageName];
    // 加入数组
    [imageArr addObject:image];
}
// 设置动画图片
imageView.animationImages = imageArr;

设置动画的播放次数

imageView.animationRepeatCount = 0;

设置播放时长

// 1秒30帧, 一张图片的时间 = 1/30 = 0.03333 20 * 0.0333
imageView.animationDuration = 1.0;

开始动画

[self.imageView startAnimating];

结束动画

[self.imageView stopAnimating];

九宫格缩放图片（用于类似微信，短信的气泡框）

//创建UIImage对象
UIImage *image = [UIImage imageNamed:@"chat_send_nor"];

//创建UIImage对象
CGFloat imageWidth = image.size.width;
CGFloat imageHeight = image.size.height;

// 方式一

UIImage *resizableImage = [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageHeight * 0.5, imageWidth * 0.5, imageHeight * 0.5 -1, imageWidth * 0.5 - 1)];

//UIImageResizingModeTile, 平铺
//UIImageResizingModeStretch, 拉伸(伸缩)
UIImage *resizableImage = [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageHeight * 0.5, imageWidth * 0.5, imageHeight * 0.5 -1, imageWidth * 0.5 - 1) resizingMode:UIImageResizingModeTile];

// 方式二

// 右边需要保护的区域 = 图片的width - leftCapWidth - 1
UIImage *resizableImage = [image stretchableImageWithLeftCapWidth:imageWidth * 0.5 topCapHeight:imageHeight * 0.5];