如何在ios中点击圈内圈时检测区域
我想在圈内点击时找到该区域。实际上我做了一次计算，但那不准确。
检查我编写的代码段，以便在循环视图中找到选项卡的位置。
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event" this method
float dx = touchLocation.x -160;
float dy = touchLocation.y - 240;
double angle = atan2(touchLocation.x,touchLocation.y);
/* Device is iPad */
if (count==4) {
if(angle>-1.639&&angle<=0.775)
{
area=1;
NSLog(@"touched here 1 ********************************** ");
}
else if(angle>0.775&&angle<=1.579)
{
area=2;
NSLog(@"touched here 2********************************** ");
}
else if(angle>1.579&&angle<=2.466)
{
area=3;NSLog(@"touched here 3********************************** ");
}
else
{
area=4;NSLog(@"touched here 4 ********************************** ");
}
}
else if (count==5) {
if(angle>-1.520&&angle<=0.553)
{
area=1;
NSLog(@"touched here 1 ********************************** ");
}
else if(angle>0.553&&angle<=1.262)
{
area=2;
NSLog(@"touched here 2********************************** ");
}
else if(angle>1.262&&angle<=1.884)
{
area=3;NSLog(@"touched here 3********************************** ");
}
else if(angle>1.884&&angle<=2.644)
{
area=4;NSLog(@"touched here 4 ********************************** ");
}
else
{
area=5;NSLog(@"touched here 5 ********************************** ");
}
}
else if (count==6) {
if(angle>-1.5707&&angle<=0.4692)
{
area=1;
NSLog(@"touched here 1 ********************************** ");
}
else if(angle>0.4692&&angle<=1.0219)
{
area=2;
NSLog(@"touched here 2********************************** ");
}
else if(angle>1.0219&&angle<=1.5707)
{
area=3;NSLog(@"touched here 3********************************** ");
}
else if(angle>1.5707&&angle<=2.1147)
{
area=4;NSLog(@"touched here 4 ********************************** ");
}
else if(angle>2.1147&&angle<=2.7245)
{
area=5;NSLog(@"touched here 5 ********************************** ");
}
else
{
area=6;NSLog(@"touched here 6 ********************************** ");
}
}
else if (count==7) {
if(angle>-1.5707&&angle<=0.3992)
{
area=1;
NSLog(@"touched here 1 ********************************** ");
}
else if(angle>0.3992&&angle<=0.8602)
{
area=2;
NSLog(@"touched here 2********************************** ");
}
else if(angle>0.8602&&angle<=1.346)
{
area=3;NSLog(@"touched here 3********************************** ");
}
else if(angle>1.346&&angle<=1.812)
{
area=4;NSLog(@"touched here 4 ********************************** ");
}
else if(angle>1.812&&angle<=2.304)
{
area=5;NSLog(@"touched here 5 ********************************** ");
}
else if(angle>2.304&&angle<=2.828)
{
area=6;NSLog(@"touched here 6 ********************************** ");
}
else
{
area=7;NSLog(@"touched here 7 ********************************** ");
}
}
else if (count==8){
if(angle>-1.40&&angle<=0.45)
{
area=1;
NSLog(@"touched here 1 ********************************** ");
}
else if(angle>.45&&angle<=.73)
{
area=2;
NSLog(@"touched here 2********************************** ");
}
else if(angle>.73&&angle<=1.15)
{
area=3;NSLog(@"touched here 3********************************** ");
}
else if(angle>1.15&&angle<=1.55){
area=4;NSLog(@"touched here 4 ********************************** ");
}
else if(angle>-1.55&&angle<=1.95){
area=5;NSLog(@"touched here 5 ********************************** ");
}
else if(angle>-1.95&&angle<=2.43){
area=6;NSLog(@"touched here 6 ********************************** ");
}
else if(angle>2.43&&angle<=2.98){
area=7;NSLog(@"touched here 7********************************** ");
}
// else if(angle>2.98&&angle<=-1.40){
else
{
area=8;NSLog(@"touched here 8 ********************************** ");
}
}
3 个答案:
答案 0 :(得分：7)
更新：已添加完整的工作代码
这是一些伪代码，可以帮助您找出您点击的位置。这是参考最顶层的数字。 （我假设你的圆圈的中心与视图的中心重合）：
（1）找到从圆心到触摸点的线段方向：
dx = touchPoint.x - circleCenter.x;
dy = touchPoint.y - circleCenter.y;
t = atan2(dy, dx); // some offsetting/direction adjustment might be required
（2）弄清楚触点位于哪个八分圆中。
octant = floor(4 * t/M_PI); // will return a number between 0 and 7.
如果您的扇区大小不均匀（但您知道每个扇区的单元格大小），则可以使用if-else序列。
（3）右手侧的八分圆分别具有“内部扇形”和环形。如果要测试触摸发生的两个部分中的哪一个，可以先计算触点与圆心的距离：
dist = sqrtf(dx * dx + dy * dy);
显然你需要知道每个八分圆的内半径，然后测试
if ( dist < innerRadius[i]) ... // again, you might need to adjust the angle calculations to ensure that the right indices correspond to the right sector. See (working) code below...
innerRadius[8]是一个包含每个八分圆的内半径的数组。
这是一些实际工作代码，它以编程方式生成饼图并正确检测分接位置。只需使用以下内容替换“单一视图应用程序”模板中ViewController.m的内容：
#import "ViewController.h"
static float innerRadii[] = {50, 75, 100, 125, 150, 175, 200, 225};
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
float side = 600; // square view
CGPoint center = CGPointMake(side/2, side/2);
CGFloat radius = side/2 * 0.9;
UIGraphicsBeginImageContextWithOptions(CGSizeMake(side, side), YES, 0.0);
UIBezierPath *bgPath = [UIBezierPath bezierPathWithRect:CGRectMake(0, 0, side, side)];
[[UIColor lightGrayColor] setFill];
[bgPath fill];
for (int i = 0; i < 8; i++)
{
UIBezierPath *sector = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:M_PI/4 * i endAngle:M_PI/4 * (i+1) clockwise:YES];
[sector addLineToPoint:center];
[sector closePath];
#define VAL(x) x/2 + 0.25
[[UIColor colorWithRed:VAL((float)(i % 2)) green:VAL((float)((i >> 1) % 2)) blue:VAL((float)((i >> 2) % 2)) alpha:1.0] setFill];
[sector fill];
UIBezierPath *innerSector = [UIBezierPath bezierPathWithArcCenter:center radius:innerRadii[i] startAngle:M_PI/4 * i endAngle:M_PI/4 * (i+1) clockwise:YES];
[innerSector addLineToPoint:center];
[innerSector closePath];
#define VAL1(x) (1- x)/3 + 0.5
[[UIColor colorWithRed:VAL1((float)(i % 2)) green:VAL1((float)((i >> 1) % 2)) blue:VAL1((float)((i >> 2) % 2)) alpha:1.0] setFill];
[innerSector fill];
}
UIImage *pieChartImg = UIGraphicsGetImageFromCurrentImageContext();
UIImageView *pieChartView = [[UIImageView alloc] initWithImage:pieChartImg];
pieChartView.center = self.view.center;
[self.view addSubview:pieChartView];
UITapGestureRecognizer *gr = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(identifyTappedSector:)];
pieChartView.userInteractionEnabled = YES;
[pieChartView addGestureRecognizer:gr];
}
- (void)identifyTappedSector:(UITapGestureRecognizer *)tgr
{
CGPoint touchPoint = [tgr locationInView:tgr.view];
CGPoint circleCenter = CGPointMake(tgr.view.bounds.size.width/2, tgr.view.bounds.size.height/2);
float dx = circleCenter.x - touchPoint.x;
float dy = circleCenter.y - touchPoint.y;
float t = atan2f(dy, dx) + M_PI;
NSLog(@"angle = %f", t * 180.0/M_PI);
int octant = floorf(4 * t/M_PI);
NSLog(@"You tapped octant number: %d!", octant);
float dist = sqrtf(dx * dx + dy * dy);
if (dist <= innerRadii[octant])
NSLog(@"\tYou tapped the inner sector!");
else
NSLog(@"\tYou tapped the annulus!");
}
@end
答案 1 :(得分：3)
以下是一些想法，凯文的回答很好，但没有更多的切片。
假设你在圆圈上有n个相等的切片。每个切片2 * PI / n度。要找到相应的切片，你必须从三角学中获得一些帮助，特别是我们将使用arctangents。
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [[event allTouches] anyObject];
CGPoint touchLocation = [touch locationInView:cycleView];
double radius = self.bounds.size.width;
double sliceAngle = M_PI*2 / n;
double deltaAngle = atan2(radius - touchLocation.y,touchLocation.x - radius);
//Here you might get a negative value for delta angle,
//just keep adding 2*M_PI to the result until you get a deltaAngle between 0 and 2*M_PI
//also notice that we are normalizing the aran values for the center of our frame, which is
//the origin of the circle (keep in mind that origin is the upper left corner in UIKit)
NSInteger sliceNumber = ((NSInteger)floor(deltaAngle/sliceAngle))
}
还有一件事你可以做，因为你有一个圆圈，但UIView应该有矩形形状，你可以覆盖pointInside方法只捕捉圆圈内的触摸。它看起来像这样：
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
//Assuming you have a circle, not an ellipse. And also that your frame is a square.
//Get the length of the touch point from the origin and make sure it's smaller than
//your circles radius
CGFloat length = sqrtf(point.x * point.x + point.y * point.y);
return (length < self.bounds.size.width);
//could have used height as well since you have a square
}
这些代码段未经过测试，如果它们无法按预期工作，请告诉我。
答案 2 :(得分：2)
假设你的周期UIView是cycleView。那么这可能是你的解决方案：
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [[event allTouches] anyObject];
CGPoint touchLocation = [touch locationInView:cycleView];
if(touchLocation.y < cycleView.frame.size.height/2 && touchLocation.x < cycleView.frame.size.width/2){
//touch is in upper left corner
} else if(touchLocation.y < cycleView.frame.size.height/2 && touchLocation.x >= cycleView.frame.size.width/2){
//touch is in upper right corner
} else if(touchLocation.y >= cycleView.frame.size.height/2 && touchLocation.x < cycleView.frame.size.width/2){
//touch is in lower left corner
} else if(touchLocation.y >= cycleView.frame.size.height/2 && touchLocation.x >= cycleView.frame.size.width/2){
//touch is in upper left corner
}
}
如果每个饼图都是单个UIView，这样会更容易，你可以将它们分别调用。
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