腾讯sdk学到了
1. 获取文本的高度和宽度
+ (CGFloat)heightForContent:(MyMsgTextModel *)content withWidth:(CGFloat)width { CGSize contentSize; if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) { NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc]init]; paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping; // NSDictionary *attributes = @{NSFontAttributeName:CELL_CONTENT_FONT_SIZE, NSParagraphStyleAttributeName:paragraphStyle.copy}; NSDictionary *attributes = @{NSFontAttributeName:CELL_CONTENT_FONT_SIZE}; contentSize = [content.textMsg boundingRectWithSize:CGSizeMake(width, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin attributes:attributes context:nil].size; } else{ contentSize = [content.textMsg sizeWithFont:CELL_CONTENT_FONT_SIZE constrainedToSize:CGSizeMake(width, CGFLOAT_MAX) lineBreakMode:NSLineBreakByWordWrapping]; } return contentSize.height; }
2. autolayout中一直确定不了设备的高度和宽度
可以使用 layoutSubviews, 但是这个方法会被调用多次, 所以这个方法里只能用于控制frame
3. sizeToFit
这个方法是让uiview 根据子视图 来确定size
常用与UIlabel, 根据文本来确定UILabel的size
3. - (UIImage *)stretchableImageWithLeftCapWidth:(NSInteger)leftCapWidth topCapHeight:
让uiimageview left和top方向某个范围内不被拉伸, 用于做气泡