iOS面向过程，面向对象一则实例
//面向过程编程：其中有iOS枚举和结构实例，这段能很好解释iOS中的结构和枚举：
#import
// --------------------------------------------------
// constants for the different kinds of shapes and their colors
typedef enum {
kCircle,
kRectangle,
kOblateSpheroid
} ShapeType;
typedef enum {
kRedColor,
kGreenColor,
kBlueColor
} ShapeColor;
// --------------------------------------------------
// Shape bounding rectangle
typedef struct {
int x, y, width, height;
} ShapeRect;
// --------------------------------------------------
// The Shape
typedef struct {
ShapeType type;
ShapeColor fillColor;
ShapeRect bounds;
} Shape;
// --------------------------------------------------
// convert from the ShapeColor enum value to a human-readable name
NSString *colorName (ShapeColor colorName)
{
switch (colorName) {
case kRedColor:
return @"red";
break;
case kGreenColor:
return @"green";
break;
case kBlueColor:
return @"blue";
break;
}
return @"no clue";
} // colorName
void drawCircle (ShapeRect bounds,
ShapeColor fillColor)
{
NSLog (@"drawing a circle at (%d %d %d %d) in %@",
bounds.x, bounds.y,
bounds.width, bounds.height,
colorName(fillColor));
} // drawCircle
void drawRectangle (ShapeRect bounds,
ShapeColor fillColor)
{
NSLog (@"drawing a rectangle at (%d %d %d %d) in %@",
bounds.x, bounds.y,
bounds.width, bounds.height,
colorName(fillColor));
} // drawRectangle
void drawEgg (ShapeRect bounds,
ShapeColor fillColor)
{
NSLog (@"drawing an egg at (%d %d %d %d) in %@",
bounds.x, bounds.y,
bounds.width, bounds.height,
colorName(fillColor));
} // drawEgg
// --------------------------------------------------
// Draw the shapes
void drawShapes (Shape shapes[], int count)
{
int i;
for (i = 0; i < count; i++) {
switch (shapes[i].type) {
case kCircle:
drawCircle (shapes[i].bounds,
shapes[i].fillColor);
break;
case kRectangle:
drawRectangle (shapes[i].bounds,
shapes[i].fillColor);
break;
case kOblateSpheroid:
drawEgg (shapes[i].bounds,
shapes[i].fillColor);
break;
}
}
} // drawShapes
// --------------------------------------------------
// The main function. Make the shapes and draw them
int main (int argc, const char * argv[])
{
Shape shapes[3];
ShapeRect rect0 = { 0, 0, 10, 30 };
shapes[0].type = kCircle;
shapes[0].fillColor = kRedColor;
shapes[0].bounds = rect0;
ShapeRect rect1 = { 30, 40, 50, 60 };
shapes[1].type = kRectangle;
shapes[1].fillColor = kGreenColor;
shapes[1].bounds = rect1;
ShapeRect rect2 = { 15, 18, 37, 29 };
shapes[2].type = kOblateSpheroid;
shapes[2].fillColor = kBlueColor;
shapes[2].bounds = rect2;
drawShapes (shapes, 3);
return (0);
} // main
面向对象的编程：
#import
// --------------------------------------------------
// constants for the different kinds of shapes and their colors
typedef enum {
kRedColor,
kGreenColor,
kBlueColor
} ShapeColor;
// --------------------------------------------------
// Shape bounding rectangle
typedef struct {
int x, y, width, height;
} ShapeRect;
// --------------------------------------------------
// convert from the ShapeColor enum value to a human-readable name
NSString *colorName (ShapeColor color)
{
NSString *colorName;
switch (color) {
case kRedColor:
colorName = @"red";
break;
case kGreenColor:
colorName = @"green";
break;
case kBlueColor:
colorName = @"blue";
break;
default:
colorName = @"oops! Unexpected color";
break;
}
return (colorName);
} // colorName
// --------------------------------------------------
// Shapes base class
@interface Shape : NSObject
{
ShapeColor fillColor;
ShapeRect bounds;
}
- (void) setFillColor: (ShapeColor) fillColor;
- (void) setBounds: (ShapeRect) bounds;
- (void) draw;
@end // Shape
@implementation Shape
- (void) setFillColor: (ShapeColor) c
{
fillColor = c;
} // setFillColor
- (void) setBounds: (ShapeRect) b
{
bounds = b;
} // setBounds
- (void) draw
{
} // draw
@end // Shape
// --------------------------------------------------
// All about Triangles
@interface Triangle : Shape
@end // Triangle
@implementation Triangle
- (void) draw
{
NSLog (@"drawing a triangle at (%d %d %d %d) in %@",
bounds.x, bounds.y,
bounds.width, bounds.height,
colorName(fillColor));
} // draw
@end // Triangle
// --------------------------------------------------
// All about Circles
@interface Circle : Shape
@end // Circle
@implementation Circle
// I'm new!
- (void) setFillColor: (ShapeColor) c
{
if (c == kRedColor) {
c = kGreenColor;
}
[super setFillColor: c];
} // setFillColor
- (void) draw
{
NSLog (@"drawing a circle at (%d %d %d %d) in %@",
bounds.x, bounds.y,
bounds.width, bounds.height,
colorName(fillColor));
} // draw
@end // Circle
// --------------------------------------------------
// All about Rectangles
@interface Rectangle : Shape
@end // Rectangle
@implementation Rectangle
- (void) draw
{
NSLog (@"drawing a rectangle at (%d %d %d %d) in %@",
bounds.x, bounds.y,
bounds.width, bounds.height,
colorName(fillColor));
} // draw
@end // Rectangle
// --------------------------------------------------
// All about OblateSphereoids
@interface OblateSphereoid : Shape
@end // OblateSphereoid
@implementation OblateSphereoid
- (void) draw
{
NSLog (@"drawing an egg at (%d %d %d %d) in %@",
bounds.x, bounds.y,
bounds.width, bounds.height,
colorName(fillColor));
} // draw
@end // OblateSphereoid
// --------------------------------------------------
// Draw the shapes
void drawShapes (id shapes[], int count)
{
int i;
for (i = 0; i < count; i++) {
id shape = shapes[i];
[shape draw];
}
} // drawShapes
// --------------------------------------------------
// The main function. Make the shapes and draw them
int main (int argc, const char * argv[])
{
id shapes[4]; // I'm different!
ShapeRect rect0 = { 0, 0, 10, 30 };
shapes[0] = [Circle new];
[shapes[0] setBounds: rect0];
[shapes[0] setFillColor: kRedColor];
ShapeRect rect1 = { 30, 40, 50, 60 };
shapes[1] = [Rectangle new];
[shapes[1] setBounds: rect1];
[shapes[1] setFillColor: kGreenColor];
ShapeRect rect2 = { 15, 19, 37, 29 };
shapes[2] = [OblateSphereoid new];
[shapes[2] setBounds: rect2];
[shapes[2] setFillColor: kBlueColor];
ShapeRect rect3 = { 47, 32, 80, 50 }; // I'm new!
shapes[3] = [Triangle new];
[shapes[3] setBounds: rect3];
[shapes[3] setFillColor: kRedColor];
drawShapes (shapes, 4); // I'm different!
return (0);
} // main