iPhone SDK:从UIImageViewClass调用方法到ViewController

在.m ImageView类文件中有此函数

- (UIColor*) getPixelColorAtLocation:(CGPoint)point {

如何从视图控制器调用此函数？我试过了`

    - (void)viewDidLoad
{
    CGPoint point = CGPointMake(100, 100);
    UIColor* color = [ImageView getPixelColorAtLocation:point];
}`

但这给了我一个警告：“扇区‘getPixelColorAtLocation:’没有已知的类方法（我确实将ImageView类文件导入了view控制器）

ImageView中的My.h文件

    #import <Foundation/Foundation.h>
@interface ImageView : UIImageView {
UIColor* lastColor;
//id pickedColorDelegate;
}

@property (nonatomic, retain) UIColor* lastColor;
//@property (nonatomic, retain) id pickedColorDelegate;


- (UIColor*) getPixelColorAtLocation:(CGPoint)point;
- (CGContextRef) createARGBBitmapContextFromImage:(CGImageRef)inImage;
@end

    #import "ImageView.h"
#import "ViewController.h"
#import <CoreGraphics/CoreGraphics.h>
#import <QuartzCore/CoreAnimation.h>
@implementation ImageView

@synthesize lastColor;
//@synthesize pickedColorDelegate;
- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

- (void) touchesEnded:(NSSet*)touches withEvent:(UIEvent*)event {
    if (self.hidden==YES) {
        //color wheel is hidden, so don't handle  this as a color wheel event.
        [[self nextResponder] touchesEnded:touches withEvent:event];
        return;
    }

    UITouch* touch = [touches anyObject];
   // ColorPickerAppDelegate *mainDelegate = (ColorPickerAppDelegate *)[[UIApplication sharedApplication] delegate];
    CGPoint point = [touch locationInView:self]; //where image was tapped

    self.lastColor = [self getPixelColorAtLocation:point];
    NSLog(@"color %@",lastColor);
    //[pickedColorDelegate pickedColor:(UIColor*)self.lastColor];
}


- (UIColor*) getPixelColorAtLocation:(CGPoint)point {
    UIColor* color = nil;
    CGImageRef inImage = self.image.CGImage;
    // Create off screen bitmap context to draw the image into. Format ARGB is 4 bytes for each pixel: Alpa, Red, Green, Blue
    CGContextRef cgctx = [self createARGBBitmapContextFromImage:inImage];
    if (cgctx == NULL) { return nil; /* error */ }

    size_t w = CGImageGetWidth(inImage);
    size_t h = CGImageGetHeight(inImage);
    CGRect rect = {{0,0},{w,h}};

    // Draw the image to the bitmap context. Once we draw, the memory
    // allocated for the context for rendering will then contain the
    // raw image data in the specified color space.
    CGContextDrawImage(cgctx, rect, inImage);

    // Now we can get a pointer to the image data associated with the bitmap
    // context.
    unsigned char* data = CGBitmapContextGetData (cgctx);
    if (data != NULL) {
        //offset locates the pixel in the data from x,y.
        //4 for 4 bytes of data per pixel, w is width of one row of data.
        int offset = 4*((w*round(point.y))+round(point.x));
        int alpha =  data[offset];
        int red = data[offset+1];
        int green = data[offset+2];
        int blue = data[offset+3];
        NSLog(@"offset: %i colors: RGB A %i %i %i  %i",offset,red,green,blue,alpha);
        color = [UIColor colorWithRed:(red/255.0f) green:(green/255.0f) blue:(blue/255.0f) alpha:(alpha/255.0f)];
    }

    // When finished, release the context
    CGContextRelease(cgctx);
    // Free image data memory for the context
    if (data) { free(data); }

    return color;
}



- (CGContextRef) createARGBBitmapContextFromImage:(CGImageRef) inImage {

    CGContextRef    context = NULL;
    CGColorSpaceRef colorSpace;
    void *          bitmapData;
    int             bitmapByteCount;
    int             bitmapBytesPerRow;

    // Get image width, height. We'll use the entire image.
    size_t pixelsWide = CGImageGetWidth(inImage);
    size_t pixelsHigh = CGImageGetHeight(inImage);

    // Declare the number of bytes per row. Each pixel in the bitmap in this
    // example is represented by 4 bytes; 8 bits each of red, green, blue, and
    // alpha.
    bitmapBytesPerRow   = (pixelsWide * 4);
    bitmapByteCount     = (bitmapBytesPerRow * pixelsHigh);

    // Use the generic RGB color space.
    colorSpace = CGColorSpaceCreateDeviceRGB();

    if (colorSpace == NULL)
    {
        fprintf(stderr, "Error allocating color space\n");
        return NULL;
    }

    // Allocate memory for image data. This is the destination in memory
    // where any drawing to the bitmap context will be rendered.
    bitmapData = malloc( bitmapByteCount );
    if (bitmapData == NULL)
    {
        fprintf (stderr, "Memory not allocated!");
        CGColorSpaceRelease( colorSpace );
        return NULL;
    }

    // Create the bitmap context. We want pre-multiplied ARGB, 8-bits
    // per component. Regardless of what the source image format is
    // (CMYK, Grayscale, and so on) it will be converted over to the format
    // specified here by CGBitmapContextCreate.
    context = CGBitmapContextCreate (bitmapData,
                                     pixelsWide,
                                     pixelsHigh,
                                     8,      // bits per component
                                     bitmapBytesPerRow,
                                     colorSpace,
                                     kCGImageAlphaPremultipliedFirst);
    if (context == NULL)
    {
        free (bitmapData);
        fprintf (stderr, "Context not created!");
    }

    // Make sure and release colorspace before returning
    CGColorSpaceRelease( colorSpace );

    return context;
}

#导入
@接口ImageView:UIImageView{
UIColor*lastColor；
//id pickedColorDelegate；
}
@属性（非原子，保留）UIColor*lastColor；
//@属性（非原子，保留）id pickedColorDelegate；
-（UIColor*）获取像素颜色定位：（CGPoint）点；
-（CGContextRef）在图像中创建argbbitMapContextFromImage:（CGImageRef）；
@结束

ImageView中的My.m文件

    #import <Foundation/Foundation.h>
@interface ImageView : UIImageView {
UIColor* lastColor;
//id pickedColorDelegate;
}

@property (nonatomic, retain) UIColor* lastColor;
//@property (nonatomic, retain) id pickedColorDelegate;


- (UIColor*) getPixelColorAtLocation:(CGPoint)point;
- (CGContextRef) createARGBBitmapContextFromImage:(CGImageRef)inImage;
@end

    #import "ImageView.h"
#import "ViewController.h"
#import <CoreGraphics/CoreGraphics.h>
#import <QuartzCore/CoreAnimation.h>
@implementation ImageView

@synthesize lastColor;
//@synthesize pickedColorDelegate;
- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

- (void) touchesEnded:(NSSet*)touches withEvent:(UIEvent*)event {
    if (self.hidden==YES) {
        //color wheel is hidden, so don't handle  this as a color wheel event.
        [[self nextResponder] touchesEnded:touches withEvent:event];
        return;
    }

    UITouch* touch = [touches anyObject];
   // ColorPickerAppDelegate *mainDelegate = (ColorPickerAppDelegate *)[[UIApplication sharedApplication] delegate];
    CGPoint point = [touch locationInView:self]; //where image was tapped

    self.lastColor = [self getPixelColorAtLocation:point];
    NSLog(@"color %@",lastColor);
    //[pickedColorDelegate pickedColor:(UIColor*)self.lastColor];
}


- (UIColor*) getPixelColorAtLocation:(CGPoint)point {
    UIColor* color = nil;
    CGImageRef inImage = self.image.CGImage;
    // Create off screen bitmap context to draw the image into. Format ARGB is 4 bytes for each pixel: Alpa, Red, Green, Blue
    CGContextRef cgctx = [self createARGBBitmapContextFromImage:inImage];
    if (cgctx == NULL) { return nil; /* error */ }

    size_t w = CGImageGetWidth(inImage);
    size_t h = CGImageGetHeight(inImage);
    CGRect rect = {{0,0},{w,h}};

    // Draw the image to the bitmap context. Once we draw, the memory
    // allocated for the context for rendering will then contain the
    // raw image data in the specified color space.
    CGContextDrawImage(cgctx, rect, inImage);

    // Now we can get a pointer to the image data associated with the bitmap
    // context.
    unsigned char* data = CGBitmapContextGetData (cgctx);
    if (data != NULL) {
        //offset locates the pixel in the data from x,y.
        //4 for 4 bytes of data per pixel, w is width of one row of data.
        int offset = 4*((w*round(point.y))+round(point.x));
        int alpha =  data[offset];
        int red = data[offset+1];
        int green = data[offset+2];
        int blue = data[offset+3];
        NSLog(@"offset: %i colors: RGB A %i %i %i  %i",offset,red,green,blue,alpha);
        color = [UIColor colorWithRed:(red/255.0f) green:(green/255.0f) blue:(blue/255.0f) alpha:(alpha/255.0f)];
    }

    // When finished, release the context
    CGContextRelease(cgctx);
    // Free image data memory for the context
    if (data) { free(data); }

    return color;
}



- (CGContextRef) createARGBBitmapContextFromImage:(CGImageRef) inImage {

    CGContextRef    context = NULL;
    CGColorSpaceRef colorSpace;
    void *          bitmapData;
    int             bitmapByteCount;
    int             bitmapBytesPerRow;

    // Get image width, height. We'll use the entire image.
    size_t pixelsWide = CGImageGetWidth(inImage);
    size_t pixelsHigh = CGImageGetHeight(inImage);

    // Declare the number of bytes per row. Each pixel in the bitmap in this
    // example is represented by 4 bytes; 8 bits each of red, green, blue, and
    // alpha.
    bitmapBytesPerRow   = (pixelsWide * 4);
    bitmapByteCount     = (bitmapBytesPerRow * pixelsHigh);

    // Use the generic RGB color space.
    colorSpace = CGColorSpaceCreateDeviceRGB();

    if (colorSpace == NULL)
    {
        fprintf(stderr, "Error allocating color space\n");
        return NULL;
    }

    // Allocate memory for image data. This is the destination in memory
    // where any drawing to the bitmap context will be rendered.
    bitmapData = malloc( bitmapByteCount );
    if (bitmapData == NULL)
    {
        fprintf (stderr, "Memory not allocated!");
        CGColorSpaceRelease( colorSpace );
        return NULL;
    }

    // Create the bitmap context. We want pre-multiplied ARGB, 8-bits
    // per component. Regardless of what the source image format is
    // (CMYK, Grayscale, and so on) it will be converted over to the format
    // specified here by CGBitmapContextCreate.
    context = CGBitmapContextCreate (bitmapData,
                                     pixelsWide,
                                     pixelsHigh,
                                     8,      // bits per component
                                     bitmapBytesPerRow,
                                     colorSpace,
                                     kCGImageAlphaPremultipliedFirst);
    if (context == NULL)
    {
        free (bitmapData);
        fprintf (stderr, "Context not created!");
    }

    // Make sure and release colorspace before returning
    CGColorSpaceRelease( colorSpace );

    return context;
}

#导入“ImageView.h”
#导入“ViewController.h”
#进口
#进口
@实现图像视图
@合成lastColor；
//@综合挑选颜色代表；
-（id）initWithFrame:（CGRect）帧
{
self=[super initWithFrame:frame]；
如果（自我）{
//初始化代码
}
回归自我；
}
-（void）touchesend:（NSSet*）toucheevent:（UIEvent*）event{
如果（self.hidden==是）{
//颜色控制盘是隐藏的，因此不要将其作为颜色控制盘事件处理。
[[self nextResponder]touchesend:toucheevent:event]；
返回；
}
UITouch*touch=[触摸任何对象]；
//ColorPickerAppDelegate*mainDelegate=（ColorPickerAppDelegate*）[[UIApplication sharedApplication]委托]；
CGPoint=[touch locationInView:self]；//点击图像的位置
self.lastColor=[self-getPixelColorAtLocation:point]；
NSLog（@“颜色%@”，lastColor）；
//[pickedColorDelegate pickedColor:（UIColor*）self.lastColor]；
}
-（UIColor*）获取像素颜色定位：（CGPoint）点{
UIColor*color=nil；
CGImageRef inImage=self.image.CGImage；
//创建屏幕外位图上下文以绘制图像。格式ARGB为每个像素4个字节：Alpa、红色、绿色、蓝色
CGContextRef cgctx=[self-createARGBBitmapContextFromImage:inImage]；
如果（cgctx==NULL）{返回nil；/*error*/}
尺寸w=CGImageGetWidth（InImages）；
大小\u t h=CGImageGetHeight（InImages）；
CGRect rect={{0,0}，{w，h}；
//将图像绘制到位图上下文。一旦绘制，内存
//然后，为渲染上下文分配的将包含
//指定颜色空间中的原始图像数据。
CGContextDrawImage（cgctx、rect、inImage）；
//现在我们可以得到一个指向与位图关联的图像数据的指针
//上下文。
无符号字符*数据=CGBitmapContextGetData（cgctx）；
如果（数据！=NULL）{
//偏移量从x，y定位数据中的像素。
//4对于每像素4字节的数据，w是一行数据的宽度。
整数偏移=4*（（w*圆（点y））+圆（点x））；
int alpha=数据[偏移量]；
int red=数据[偏移量+1]；
int绿色=数据[偏移量+2]；
蓝色整数=数据[偏移量+3]；
NSLog（@“偏移量：%i颜色：RGB A%i%i%i”，偏移量，红色，绿色，蓝色，alpha）；
颜色=[UIColor color WITHRED:（红色/255.0f）绿色：（绿色/255.0f）蓝色：（蓝色/255.0f）阿尔法（阿尔法/255.0f）]；
}
//完成后，释放上下文
CGContextRelease（cgctx）；
//为上下文释放图像数据内存
if（data）{free（data）；}
返回颜色；
}
-（CGContextRef）在图像中创建argbbitMapContextFromImage:（CGImageRef）{
CGContextRef context=NULL；
CGCOLORSPACTEREF色彩空间；
void*位图数据；
int位映射字节计数；
int bitmapBytesPerRow；
//获取图像宽度和高度。我们将使用整个图像。
大小\u t像素宽度=CGImageGetWidth（inImage）；
大小\u t像素H=CGImageGetHeight（inImage）；
//声明每行的字节数。此对话框中位图中的每个像素
//示例由4个字节表示；红色、绿色、蓝色和蓝色各8位
//阿尔法。
bitmapBytesPerRow=（像素宽度*4）；
bitmapByteCount=（bitmapBytesPerRow*pixelsHigh）；
//使用通用RGB颜色空间。
colorSpace=CGColorSpaceCreateDeviceRGB（）；
if（colorSpace==NULL）
{
fprintf（stderr，“分配颜色空间时出错”）；
返回NULL；
}
//为图像数据分配内存。这是内存中的目标
//将渲染位图上下文中的任何图形。
bitmapData=malloc（bitmapByteCount）；
if（bitmapData==NULL）
{
fprintf（stderr，“内存未分配！”）；
CGCOLORSPACTERELEASE（色彩空间）；
返回NULL；
}
//创建位图上下文。我们需要预乘的ARGB，8位
//每个组件。无论源图像格式是什么
//（CMYK、灰度等）它将转换为
//此处由CGBitmapContextCreate指定。
上下文=CGBitmapContextCreate（bitmapData，
pixelsWide，
pixelsHigh，
8，//每个组件的位
bitmapBytesPerRow，
色彩空间，
KCGIMAGEAlphaPremultipledFirst）；
if（上下文==NULL）
{
免费（位图数据）；
fprintf（stderr，“未创建上下文！”）；
}
//确保在返回之前释放颜色空间
CGCOLORSPACTERELEASE（色彩空间）；
返回上下文；
}

您必须在实例中调用ImageView（

使用alloc]init]

） 如果你使用

- (UIColor*) getPixelColorAtLocation:(CGPoint)point 

或者让它静止

+ (UIColor*) getPixelColorAtLocation:(CGPoint)point

---

在你的

ImageView

类的

.h

文件中定义你的方法，我知道了！好吧，所以当我创建ImageView类时，它没有连接到我的目标，这就是为什么它没有接收到任何信号，也不允许我调用该类的方法。苹果又一次让你的生活痛苦了！不管怎样，是为了将类文件连接到目标，我遵循以下步骤：