本文主要给大家介绍了利用iOS实现一个可以在屏幕中自由移动的按钮的相关内容，分享出来供大家参考学习，下面话不多说，来一起看看详细的介绍。
效果图如下：
其实实现很简单，只需要写.m就可以了
示例代码
#import "CrossBtnVC.h"
@interface CrossBtnVC ()
{
CGPoint beginPoint;
CGFloat rightMargin;
CGFloat leftMargin;
CGFloat topMargin;
CGFloat bottomMargin;
CGMutablePathRef pathRef;
}
@property (nonatomic,strong) UIButton *crossBtn;//聊天移动
@end
@implementation CrossBtnVC
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
_crossBtn = [UIButton buttonWithType:UIButtonTypeCustom];
[_crossBtn setImage:[UIImage imageNamed:@"移动聊天"] forState:UIControlStateNormal];
_crossBtn.frame = CGRectMake(UI_View_Width-54*UI_Width_Scale, UI_View_Height-103, 40, 40);
[self.view addSubview:_crossBtn];
[_crossBtn addTarget:self action:@selector(btnAction:) forControlEvents:UIControlEventTouchUpInside];
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(handlePan:)];
[_crossBtn addGestureRecognizer:pan];
rightMargin = [UIScreen mainScreen].bounds.size.width-30;
leftMargin = 30;
bottomMargin = [UIScreen mainScreen].bounds.size.height-30-50;
topMargin = 30+64;
pathRef=CGPathCreateMutable();
CGPathMoveToPoint(pathRef, NULL, leftMargin, topMargin);
CGPathAddLineToPoint(pathRef, NULL, rightMargin, topMargin);
CGPathAddLineToPoint(pathRef, NULL, rightMargin, bottomMargin);
CGPathAddLineToPoint(pathRef, NULL, leftMargin, bottomMargin);
CGPathAddLineToPoint(pathRef, NULL, leftMargin, topMargin);
CGPathCloseSubpath(pathRef);
}
#pragma mark - 事件
- (void)btnAction:(UIButton*)sender{
}
#pragma mark - 手势
- (void)handlePan:(UIPanGestureRecognizer *)pan
{
if (pan.state == UIGestureRecognizerStateBegan) {
beginPoint = [pan locationInView:self.view];
}else if (pan.state == UIGestureRecognizerStateChanged){
CGPoint nowPoint = [pan locationInView:self.view];
float offsetX = nowPoint.x - beginPoint.x;
float offsetY = nowPoint.y - beginPoint.y;
CGPoint centerPoint = CGPointMake(beginPoint.x + offsetX, beginPoint.y + offsetY);
if (CGPathContainsPoint(pathRef, NULL, centerPoint, NO))
{
_crossBtn.center = centerPoint;
}else{
if (centerPoint.y>bottomMargin)
{
if (centerPoint.x<rightMargin&¢erPoint.x>leftMargin) {
_crossBtn.center = CGPointMake(beginPoint.x + offsetX, bottomMargin);
}
}
else if (centerPoint.y<topMargin)
{
if (centerPoint.x<rightMargin&¢erPoint.x>leftMargin) {
_crossBtn.center = CGPointMake(beginPoint.x + offsetX, topMargin);
}
}
else if (centerPoint.x>rightMargin)
{
_crossBtn.center = CGPointMake(rightMargin, beginPoint.y + offsetY);
}
else if (centerPoint.x<leftMargin)
{
_crossBtn.center = CGPointMake(leftMargin, beginPoint.y + offsetY);
}
}
}else if (pan.state == UIGestureRecognizerStateEnded || pan.state == UIGestureRecognizerStateFailed){
}
}
@end
以上就是这篇文章的全部内容了，希望本文的内容对各位iOS开发者们能带来一定的帮助，如果有疑问大家可以留言交流，谢谢大家对的支持。
