UITableViewCell 自定义绘制 性能高

//

//  FoodListTableViewCellB.m

//  BabyFood

//

//  Created by zhuang chaoxiao on 16/3/7.

//  Copyright © 2016年 zhuang chaoxiao. All rights reserved.

//

#import "FoodListTableViewCellB.h"

#import "NSString+Additions.h"

#import "CommData.h"

@interface FoodListTableViewCellB()

{

UIImageView * postImgView;

BOOL drawed;

}

@end

@implementation FoodListTableViewCellB

-(id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier

{

self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];

if( self )

{

postImgView = [[UIImageView alloc]initWithFrame:CGRectZero];

[self.contentView addSubview:postImgView];

}

return self;

}

- (void)awakeFromNib {

// Initialization code

}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated {

[super setSelected:selected animated:animated];

// Configure the view for the selected state

}

-(void)draw

{

if( drawed )

{

NSLog(@"drawed~~~");

return;

}

drawed = YES;

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

CGRect rect = CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width,70);

UIGraphicsBeginImageContextWithOptions(rect.size, YES, 0);

CGContextRef context = UIGraphicsGetCurrentContext();

[[UIColor whiteColor]set];

CGContextFillRect(context, rect);

[self.model.title drawInContext:context withPosition:CGPointMake(FOOD_CELL_TITLE_X, FOOD_CELL_TITLE_Y) andFont:FontWithSize(15) andTextColor:[UIColor blackColor] andHeight:FOOD_CELL_TITLE_H andWidth:FOOD_CELL_TITLE_W];

[self.model.detail[0][@"text"] drawInRect:CGRectMake(FOOD_CELL_DESC_X, FOOD_CELL_DESC_Y, FOOD_CELL_DESC_W, FOOD_CELL_DESC_H) withAttributes:@{NSFontAttributeName: [UIFont systemFontOfSize:14],NSForegroundColorAttributeName: [UIColor grayColor]}];

//[self.model.image drawInRect:CGRectMake(FOOD_CELL_IMG_X_GAP, FOOD_CELL_IMG_Y_GAP, FOOD_CELL_IMG_W, FOOD_CELL_IMG_W)];

[[self createRoundedRectImage:self.model.image size:CGSizeMake(FOOD_CELL_IMG_W, FOOD_CELL_IMG_W)] drawInRect:CGRectMake(FOOD_CELL_IMG_X_GAP, FOOD_CELL_IMG_Y_GAP, FOOD_CELL_IMG_W, FOOD_CELL_IMG_W)];

UIImage * t = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

dispatch_async(dispatch_get_main_queue(), ^{

postImgView.frame = rect;

postImgView.image = nil;

postImgView.image = t;

});

});

}

- (void)clear{

if (!drawed) {

return;

}

NSLog(@"clear~~~");

postImgView.frame = CGRectZero;

postImgView.image = nil;

drawed = NO;

}

void addRoundedRectToPath(CGContextRef context, CGRect rect, float ovalWidth,

float ovalHeight)

{

float fw, fh;

if (ovalWidth == 0 || ovalHeight == 0) {

CGContextAddRect(context, rect);

return;

}

CGContextSaveGState(context);

CGContextTranslateCTM(context, CGRectGetMinX(rect), CGRectGetMinY(rect));

CGContextScaleCTM(context, ovalWidth, ovalHeight);

fw = CGRectGetWidth(rect) / ovalWidth;

fh = CGRectGetHeight(rect) / ovalHeight;

CGContextMoveToPoint(context, fw, fh/2);  // Start at lower right corner

CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1);  // Top right corner

CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1); // Top left corner

CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1); // Lower left corner

CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); // Back to lower right

CGContextClosePath(context);

CGContextRestoreGState(context);

}

-(id) createRoundedRectImage:(UIImage*)image size:(CGSize)size

{

// the size of CGContextRef

int w = size.width;

int h = size.height;

UIImage *img = image;

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);

CGRect rect = CGRectMake(0, 0, w, h);

CGContextBeginPath(context);

addRoundedRectToPath(context, rect, 10, 10);

CGContextClosePath(context);

CGContextClip(context);

CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);

CGImageRef imageMasked = CGBitmapContextCreateImage(context);

CGContextRelease(context);

CGColorSpaceRelease(colorSpace);

return [UIImage imageWithCGImage:imageMasked];

}

@end