iOS编写一个画板,可以变化颜色,字体大小

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#import "DrawView.h"

@implementation DrawView

- (id)initWithFrame:(CGRect)frame

{

self = [superinitWithFrame:frame];

if (self) {

// Initialization code

self.lineArray = [NSMutableArrayarrayWithCapacity:1];

self.array = [NSMutableArrayarrayWithCapacity:1];

self.arraySize = [NSMutableArrayarrayWithCapacity:1];

UIButton *button = [UIButtonbuttonWithType:UIButtonTypeSystem];

button.frame =CGRectMake(20,400, 60, 40);

button.backgroundColor = [UIColorgreenColor];

[selfaddSubview:button];

[button setTitle:@"撤消"forState:UIControlStateNormal];

[button addTarget:selfaction:@selector(buttonPress:)forControlEvents:UIControlEventTouchUpInside];

self.slider = [[UISlideralloc]initWithFrame:CGRectMake(100,400, 200, 40)];

[selfaddSubview:_slider];

_slider.minimumValue =1.0;

_slider.maximumValue =9.0;

[_sliderrelease];

NSMutableArray *array = [NSMutableArrayarrayWithObjects:@"红",

@"橙",

@"黄",

@"绿",

@"青",

@"蓝",

@"紫",nil];

self.segControl = [[UISegmentedControlalloc]initWithItems:array];

_segControl.frame =CGRectMake(10,460, 300, 20);

_segControl.selectedSegmentIndex =0;

[selfaddSubview:_segControl];

[_segControlrelease];

}

return self;

}

- (void)dealloc

{

self.lineArray =nil;

[superdealloc];

}

- (void)buttonPress:(UIButton *)button

{

[_lineArrayremoveLastObject];

[_arrayremoveLastObject];

[_arraySizeremoveLastObject];

[selfsetNeedsDisplay];

}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

NSMutableArray *pointarray = [NSMutableArrayarrayWithCapacity:1];

[_lineArrayaddObject:pointarray];

NSInteger temp =_segControl.selectedSegmentIndex;

[self.arrayaddObject:[NSNumbernumberWithInt:temp]];

[self.arraySizeaddObject:[NSNumbernumberWithFloat:_slider.value]];

}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event

{

UITouch *touch = [touches anyObject];

CGPoint point = [touch locationInView:self];

NSValue *pointvalue = [NSValuevalueWithCGPoint:point];

[[_lineArraylastObject] addObject:pointvalue];

[selfsetNeedsDisplay];

}

- (CGColorRef)choice:(NSInteger)temp

{

CGColorRef color = [UIColorwhiteColor].CGColor;

switch (temp) {

case 0:

color = [UIColorredColor].CGColor;

break;

case 1:

color = [UIColororangeColor].CGColor;

break;

case 2:

color = [UIColoryellowColor].CGColor;

break;

case 3:

color = [UIColorgreenColor].CGColor;

break;

case 4:

color = [UIColorcyanColor].CGColor;

break;

case 5:

color = [UIColorblueColor].CGColor;

break;

case 6:

color = [UIColorpurpleColor].CGColor;

break;

default:

break;

}

return color;

}

// Only override drawRect: if you perform custom drawing.

// An empty implementation adversely affects performance during animation.

- (void)drawRect:(CGRect)rect

{

// Drawing code

CGContextRef context =UIGraphicsGetCurrentContext();

//设置画笔颜色

for (int i =0 ; i < _lineArray.count; i++) {

NSMutableArray *point = [_lineArrayobjectAtIndex:i];

NSInteger temp = [[self.arrayobjectAtIndex:i] intValue];

CGContextSetStrokeColorWithColor(context, [selfchoice:temp]);

CGContextSetLineWidth(context, [[_arraySizeobjectAtIndex:i] floatValue]);

for (int j =0; j < (int)point.count -1; j++) {

NSValue *firstValue = [point objectAtIndex:j];

NSValue *secondValue = [point objectAtIndex:j + 1];

CGPoint firstPoint = [firstValue CGPointValue];

CGPoint secondPoint = [secondValue CGPointValue];

CGContextMoveToPoint(context, firstPoint.x, firstPoint.y);

CGContextAddLineToPoint(context, secondPoint.x, secondPoint.y);

}

CGContextStrokePath(context);

}

@end

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