This article shares the specific code for iOS to realize simple drawer effect for your reference. The specific content is as follows
Implementation ideas and steps:
1. First prepare the view to slide
#warning Step 1- (void)addChildView
{
// left
UIView *leftView = [[UIView alloc] initWithFrame:];
= [UIColor greenColor];
[ addSubview:leftView];
_leftView = leftView;
// right
UIView *rightView = [[UIView alloc] initWithFrame:];
= [UIColor blueColor];
[ addSubview:rightView];
_rightView = rightView;
// mainView
UIView *mainView = [[UIView alloc] initWithFrame:];
= [UIColor redColor];
[ addSubview:mainView];
_mainView = mainView;
}2. Monitor the touch event and record the offset in the horizontal axis direction. With the offset, the position of the view can be changed by the offset.
#warning Second Cloth- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
// Get UITouch object UITouch *touch = [touches anyObject];
// Get the current point CGPoint currentPoint = [touch locationInView:];
// Get the previous point CGPoint prePoint = [touch previousLocationInView:];
// x-axis offset: how much does x offset when the finger moves a little CGFloat offsetX = - ;
// Set the frame of the current main view _mainView.frame = [self getCurrentFrameWithOffsetX:offsetX];
_isDraging = YES;
}
How to listen for an object's properties in real time(Only listen to objects，Can't monitor structures)?kvo
// 1. Listen 2, implement: observeValueForKeyPath method /**
* Add an observer to _mainView
*
* KeyPath: Listen to the frame property
*
* options: Listen to the changes in new values
*/
[_mainView addObserver:self forKeyPath:@"frame" options:NSKeyValueObservingOptionNew context:nil]; //Read the frame of mainview in real time
// It will be called when the frame property of _mainView is changed- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
NSLog(@"%@", NSStringFromCGRect(_mainView.frame));//The current frame
if (_mainView. < 0) { // The x<0 of the main interface, move to the left // Show the right _rightView.hidden = NO;
// Hide the left _leftView.hidden = YES;
}else if (_mainView. > 0){ // Move to the right // Show left _rightView.hidden = YES;
// Hide the right _leftView.hidden = NO;
}
} How to scale the height when the x-axis is offset?
When x is offset, the y-axis shrinks to: the offset of x/
#define HMMaxY 60
// When the finger is offset a little, calculate the frame of the current main view based on the offset of the X-axis- (CGRect)getCurrentFrameWithOffsetX:(CGFloat)offsetX
{
CGFloat screenW = [UIScreen mainScreen].;
CGFloat screenH = [UIScreen mainScreen].;
// Get the y-axis offset, every point of the finger moves, how much does the y-axis offset CGFloat offsetY = offsetX * HMMaxY / screenW;//HMMaxY The maximum Y of the zoom
CGFloat scale = (screenH - 2 * offsetY) / screenH;//Proportion
if (_mainView. < 0) { // Slide to the left scale = (screenH + 2 * offsetY) / screenH;
}
// Get the previous frame CGRect frame = _mainView.frame;
+= offsetX;
= *scale;
= *scale;
= (screenH - ) * 0.5;
return frame;
}position:
#define HMRTarget 250
#define HMLTarget -220
/*
_mainView. > screenW * 0.5 Position to the right
CGRectGetMaxX(_mainView.frame) < screenW * 0.5 Position to the left -220
*/
// position- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
// Reset if (_isDraging == NO && _mainView. != 0) {
[UIView animateWithDuration:0.25 animations:^{
_mainView.frame = ;
}];
}
CGFloat screenW = [UIScreen mainScreen].;
CGFloat target = 0;
if (_mainView. > screenW * 0.5) { // Position to the right target = HMRTarget;
}else if (CGRectGetMaxX(_mainView.frame) < screenW * 0.5) { // Position to the left target = HMLTarget;
}
[UIView animateWithDuration:0.25 animations:^{
if (target) { // If you need to locate the left or right
// Get the x-axis offset CGFloat offsetX = target - _mainView.;
// Set the frame of the current main view _mainView.frame = [self getCurrentFrameWithOffsetX:offsetX];
}else{ // Restore _mainView.frame = ;
}
}];
_isDraging = NO;
}Complete:
@interface HMDrawViewController ()
@property (nonatomic, assign) BOOL isDraging;
@end
@implementation HMDrawViewController
- (void)viewDidLoad
{
// UIViewController
[super viewDidLoad];
// Do any additional setup after loading the view.
// 1. Add child controls [self addChildView];
#warning Step 3 Observe the frame changes of _mainView // 2. Monitor /**
* Add an observer to _mainView
*
* KeyPath: Listen to the frame property
*
* options: Listen to the changes in new values
*/
[_mainView addObserver:self forKeyPath:@"frame" options:NSKeyValueObservingOptionNew context:nil];
}
// It will be called when the frame property of _mainView is changed- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
NSLog(@"%@", NSStringFromCGRect(_mainView.frame));
if (_mainView. < 0) { // Move left // Show the right _rightView.hidden = NO;
// Hide the left _leftView.hidden = YES;
}else if (_mainView. > 0){ // Move to the right // Show left _rightView.hidden = YES;
// Hide the right _leftView.hidden = NO;
}
}
#warning Step 1- (void)addChildView
{
// left
UIView *leftView = [[UIView alloc] initWithFrame:];
= [UIColor greenColor];
[ addSubview:leftView];
_leftView = leftView;
// right
UIView *rightView = [[UIView alloc] initWithFrame:];
= [UIColor blueColor];
[ addSubview:rightView];
_rightView = rightView;
// mainView
UIView *mainView = [[UIView alloc] initWithFrame:];
= [UIColor redColor];
[ addSubview:mainView];
_mainView = mainView;
}
#warning Second Cloth- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
// Get UITouch object UITouch *touch = [touches anyObject];
// Get the current point CGPoint currentPoint = [touch locationInView:];
// Get the previous point CGPoint prePoint = [touch previousLocationInView:];
// x-axis offset: how much does x offset when the finger moves a little CGFloat offsetX = - ;
// Set the frame of the current main view _mainView.frame = [self getCurrentFrameWithOffsetX:offsetX];
_isDraging = YES;
}
#warning Step 4#define HMMaxY 60
// When the finger is offset a little, calculate the frame of the current main view based on the offset of the X-axis- (CGRect)getCurrentFrameWithOffsetX:(CGFloat)offsetX
{
CGFloat screenW = [UIScreen mainScreen].;
CGFloat screenH = [UIScreen mainScreen].;
// Get the y-axis offset, every point of the finger moves, how much does the y-axis offset CGFloat offsetY = offsetX * HMMaxY / screenW;
CGFloat scale = (screenH - 2 * offsetY) / screenH;
if (_mainView. < 0) { // Slide to the left scale = (screenH + 2 * offsetY) / screenH;
}
// Get the previous frame CGRect frame = _mainView.frame;
+= offsetX;
= *scale;
= *scale;
= (screenH - ) * 0.5;
return frame;
}
#define HMRTarget 250
#define HMLTarget -220
/*
_mainView. > screenW * 0.5 Position to the right
CGRectGetMaxX(_mainView.frame) < screenW * 0.5 Position to the left -220
*/
// position- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
// Reset if (_isDraging == NO && _mainView. != 0) {
[UIView animateWithDuration:0.25 animations:^{
_mainView.frame = ;
}];
}
CGFloat screenW = [UIScreen mainScreen].;
CGFloat target = 0;
if (_mainView. > screenW * 0.5) { // Position to the right target = HMRTarget;
}else if (CGRectGetMaxX(_mainView.frame) < screenW * 0.5) { // Position to the left target = HMLTarget;
}
[UIView animateWithDuration:0.25 animations:^{
if (target) { // If you need to locate the left or right
// Get the x-axis offset CGFloat offsetX = target - _mainView.;
// Set the frame of the current main view _mainView.frame = [self getCurrentFrameWithOffsetX:offsetX];
}else{ // Restore _mainView.frame = ;
}
}];
_isDraging = NO;
}The above is all the content of this article. I hope it will be helpful to everyone's study and I hope everyone will support me more.