多张图片合成大图的三种方式

//图片合成的三种方式：imgSizeArray--图片size数组，imgArray--图片数组，imgPointArray--图片origin数组

//第一种，利用drawInRect,drawAtPoint,CGContextDrawImage合成

- (UIImage*) mergedImage1OnImageSizeArr:(NSArray*)imgSizeArray WithImageArray:(NSArray*)imgArray AndImagePointArray:(NSArray*)imgPointArray

{

    float DW = self.view.frame.size.width;

    float DH = self.view.frame.size.height;

    CGImageRefNewMergeImg;

    CGSizeimageSize =CGSizeMake(DW*8, DH*8);

    UIGraphicsBeginImageContext(imageSize);

    UIImage *img = [[UIImage alloc]init];

    inti =0;

    for(imginimgArray){

        NSValue*tmpVal = imgPointArray[i];

        CGPointtmpPoint = [tmpValCGPointValue];

        [imgdrawAtPoint:CGPointMake(tmpPoint.x, tmpPoint.y)];

        //这两个方法也可以

        // NSValue *tmpVal1 = imgSizeArray[i];

        // CGSize tmpSize = [tmpVal1 CGSizeValue];

        // [img drawInRect:CGRectMake(tmpPoint.x, tmpPoint.y, tmpSize.width, tmpSize.height), img.CGImage)];

        // CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(tmpPoint.x, tmpPoint.y, tmpSize.width, tmpSize.height), img.CGImage);

        i+=1;

    }

    NewMergeImg =CGImageCreateWithImageInRect(UIGraphicsGetImageFromCurrentImageContext().CGImage,

                                               CGRectMake(0,0, DW*8, DH*8));

    UIGraphicsEndImageContext();

    UIImage*image;

    if(NewMergeImg) {

        image = [UIImageimageWithCGImage:NewMergeImg];

        CGImageRelease(NewMergeImg);

        NewMergeImg =nil;

    }

    returnimage;

}

//第二种，利用UIView layer合成

- (UIImage*) mergedImage2OnImageSizeArr:(NSArray*)imgSizeArray WithImageArray:(NSArray*)imgArray AndImagePointArray:(NSArray*)imgPointArray

{

    float DW = self.view.frame.size.width;

    float DH = self.view.frame.size.height;

     CGSizeimageSize =CGSizeMake(DW*8, DH*8);

     UIGraphicsBeginImageContext(imageSize);

     UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0.0);

     UIView*mergedView = [selfgetMergedViewSize2:imageSizepoint:imgPointArrayimage:imgArraysize:imgSizeArray];

     [mergedView.layer renderInContext:UIGraphicsGetCurrentContext()];

     mergedView =nil;

     UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

     UIGraphicsEndImageContext();

    returnimage;

}

//第三种，利用layer合成

- (UIImage*) mergedImage3OnImageSizeArr:(NSArray*)imgSizeArray WithImageArray:(NSArray*)imgArray AndImagePointArray:(NSArray*)imgPointArray

{

    float DW = self.view.frame.size.width;

    float DH = self.view.frame.size.height;

    CGSizeimageSize =CGSizeMake(DW*8, DH*8);

    UIGraphicsBeginImageContext(imageSize);

    UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0.0);

    CALayer*layers = [selfgetMergedViewSize3:imageSizepoint:imgPointArrayimage:imgArraysize:imgSizeArray];

    [layersrenderInContext:UIGraphicsGetCurrentContext()];

    layers =nil;

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    returnimage;

}

-(UIView*)getMergedViewSize2:(CGSize)size point:(NSArray*)pointArr image:(NSArray*)imageArr size:(NSArray*)sizeArr{

    UIView *view = [[UIView alloc]initWithFrame:CGRectMake(0, 0, size.width, size.height)];

    inti =0;

    UIImage *img = [[UIImage alloc]init];

    for(imginimageArr){

        NSValue*tmpVal = pointArr[i];

        CGPointtmpPoint = [tmpValCGPointValue];

        NSValue*sizeVal = sizeArr[i];

        CGSizetmpSize = [sizeValCGSizeValue];

        UIImageView*imageView = [[UIImageViewalloc]initWithFrame:(CGRect){tmpPoint.x, tmpPoint.y, tmpSize.width, tmpSize.height}];

        imageView.image= img;

        [viewaddSubview:imageView];

        imageView =nil;

        img =nil;

        i+=1;

    }

    imageArr =nil;

    returnview;

}

-(CALayer*)getMergedViewSize3:(CGSize)size point:(NSArray*)pointArr image:(NSArray*)imageArr size:(NSArray*)sizeArr{

    inti =0;

    UIImage *img = [[UIImage alloc]init];

    CALayer *layers = [CALayer layer];

    layers.frame=CGRectMake(0,0, size.width, size.height);

    for(imginimageArr){

        NSValue*tmpVal = pointArr[i];

        CGPointtmpPoint = [tmpValCGPointValue];

        NSValue*sizeVal = sizeArr[i];

        CGSizetmpSize = [sizeValCGSizeValue];

        CALayer* imageLayer = [CALayerlayer];

        imageLayer.frame=CGRectMake(tmpPoint.x, tmpPoint.y, tmpSize.width, tmpSize.height);

        imageLayer.contents= (id)img.CGImage;

        [layersaddSublayer:imageLayer];

        imageLayer =nil;

        img =nil;

        i+=1;

    }

    imageArr =nil;

    returnlayers;

}