最近，看到好多Android上的抽屜效果，也忍不住想要自己寫一個。在Android裡面可以用SlidingDrawer，很方便的實現。IOS上面就只有自己寫了。其實原理很簡單就是 UIView 的移動，和一些手勢的操作。

效果圖：

// 
// DrawerView.h 
// DrawerDemo 
// 
// Created by Zhouhaifeng on 12-3-27. 
// Copyright (c) 2012年 CJLU. All rights reserved. 
// 
 
#import <UIKit/UIKit.h> 
 
typedef enum 
{ 
  DrawerViewStateUp = 0, 
  DrawerViewStateDown 
}DrawerViewState; 
 
@interface DrawerView : UIView<UIGestureRecognizerDelegate> 
{ 
  UIImageView *arrow;     //向上拖拽時顯示的圖片   
  
  CGPoint upPoint;      //抽屜拉出時的中心點 
  CGPoint downPoint;     //抽屜收縮時的中心點 
   
  UIView *parentView;     //抽屜所在的view 
  UIView *contentView;    //抽屜裡面顯示的內容 
   
  DrawerViewState drawState; //當前抽屜狀態 
} 
 
- (id)initWithView:(UIView *) contentview parentView :(UIView *) parentview; 
- (void)handlePan:(UIPanGestureRecognizer *)recognizer; 
- (void)handleTap:(UITapGestureRecognizer *)recognizer; 
- (void)transformArrow:(DrawerViewState) state; 
 
@property (nonatomic,retain) UIView *parentView; 
@property (nonatomic,retain) UIView *contentView; 
@property (nonatomic,retain) UIImageView *arrow;  
@property (nonatomic) DrawerViewState drawState;  
 
@end 

// 
// DrawerView.m 
// DrawerDemo 
// 
// Created by Zhouhaifeng on 12-3-27. 
// Copyright (c) 2012年 CJLU. All rights reserved. 
// 
 
#import "DrawerView.h" 
 
@implementation DrawerView 
@synthesize contentView,parentView,drawState; 
@synthesize arrow; 
 
- (id)initWithView:(UIView *) contentview parentView :(UIView *) parentview; 
{ 
  self = [super initWithFrame:CGRectMake(0,0,contentview.frame.size.width, contentview.frame.size.height+40)]; 
  if (self) { 
    // Initialization code     
    contentView = contentview; 
    parentView = parentview; 
     
    //一定要開啟 
    [parentView setUserInteractionEnabled:YES]; 
     
    //嵌入內容區域的背景 
    UIImage *drawer_bg = [UIImage imageNamed:@"drawer_content.png"]; 
    UIImageView *view_bg = [[UIImageView alloc]initWithImage:drawer_bg]; 
    [view_bg setFrame:CGRectMake(0,40,contentview.frame.size.width, contentview.bounds.size.height+40)]; 
    [self addSubview:view_bg]; 
   
    //頭部拉拽的區域背景 
    UIImage *drawer_handle = [UIImage imageNamed:@"drawer_handlepng.png"]; 
    UIImageView *view_handle = [[UIImageView alloc]initWithImage:drawer_handle]; 
    [view_handle setFrame:CGRectMake(0,0,contentview.frame.size.width,40)]; 
    [self addSubview:view_handle]; 
     
    //箭頭的圖片 
    UIImage *drawer_arrow = [UIImage imageNamed:@"drawer_arrow.png"]; 
    arrow = [[UIImageView alloc]initWithImage:drawer_arrow]; 
    [arrow setFrame:CGRectMake(0,0,28,28)]; 
    arrow.center = CGPointMake(contentview.frame.size.width/2, 20); 
    [self addSubview:arrow]; 
     
    //嵌入內容的UIView 
    [contentView setFrame:CGRectMake(0,40,contentview.frame.size.width, contentview.bounds.size.height+40)]; 
    [self addSubview:contentview]; 
     
    //移動的手勢 
    UIPanGestureRecognizer *panRcognize=[[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)];  
    panRcognize.delegate=self;  
    [panRcognize setEnabled:YES];  
    [panRcognize delaysTouchesEnded];  
    [panRcognize cancelsTouchesInView];  
     
    [self addGestureRecognizer:panRcognize]; 
     
    //單擊的手勢 
    UITapGestureRecognizer *tapRecognize = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(handleTap:)];  
    tapRecognize.numberOfTapsRequired = 1;  
    tapRecognize.delegate = self;  
    [tapRecognize setEnabled :YES];  
    [tapRecognize delaysTouchesBegan];  
    [tapRecognize cancelsTouchesInView];  
     
    [self addGestureRecognizer:tapRecognize]; 
     
    //設置兩個位置的坐標 
    downPoint = CGPointMake(parentview.frame.size.width/2, parentview.frame.size.height+contentview.frame.size.height/2-40); 
    upPoint = CGPointMake(parentview.frame.size.width/2, parentview.frame.size.height-contentview.frame.size.height/2-40); 
    self.center = downPoint; 
     
    //設置起始狀態 
    drawState = DrawerViewStateDown; 
  } 
  return self; 
} 
 
 
#pragma UIGestureRecognizer Handles  
/*   
 * 移動圖片處理的函數 
 * @recognizer 移動手勢 
 */  
- (void)handlePan:(UIPanGestureRecognizer *)recognizer {  
   
   
  CGPoint translation = [recognizer translationInView:parentView];  
  if (self.center.y + translation.y < upPoint.y) { 
    self.center = upPoint; 
  }else if(self.center.y + translation.y > downPoint.y) 
  { 
    self.center = downPoint; 
  }else{ 
    self.center = CGPointMake(self.center.x,self.center.y + translation.y);  
  } 
  [recognizer setTranslation:CGPointMake(0, 0) inView:parentView];  
   
  if (recognizer.state == UIGestureRecognizerStateEnded) {  
    [UIView animateWithDuration:0.75 delay:0.15 options:UIViewAnimationOptionCurveEaseOut animations:^{  
        if (self.center.y < downPoint.y*4/5) { 
          self.center = upPoint; 
          [self transformArrow:DrawerViewStateUp]; 
        }else 
        { 
          self.center = downPoint; 
          [self transformArrow:DrawerViewStateDown]; 
        } 
 
    } completion:nil];  
  
  }   
}  
 
/* 
 * handleTap 觸摸函數 
 * @recognizer UITapGestureRecognizer 觸摸識別器 
 */  
-(void) handleTap:(UITapGestureRecognizer *)recognizer  
{  
    [UIView animateWithDuration:0.75 delay:0.15 options:UIViewAnimationOptionTransitionCurlUp animations:^{  
      if (drawState == DrawerViewStateDown) { 
        self.center = upPoint; 
        [self transformArrow:DrawerViewStateUp]; 
      }else 
      { 
        self.center = downPoint; 
        [self transformArrow:DrawerViewStateDown]; 
      } 
    } completion:nil];  
  
}  
 
/* 
 * transformArrow 改變箭頭方向 
 * state DrawerViewState 抽屜當前狀態 
 */  
-(void)transformArrow:(DrawerViewState) state 
{ 
    //NSLog(@"DRAWERSTATE :%d STATE:%d",drawState,state); 
    [UIView animateWithDuration:0.3 delay:0.35 options:UIViewAnimationOptionCurveEaseOut animations:^{  
      if (state == DrawerViewStateUp){   
          arrow.transform = CGAffineTransformMakeRotation(M_PI); 
        }else 
        { 
           arrow.transform = CGAffineTransformMakeRotation(0); 
        } 
    } completion:^(BOOL finish){ 
        drawState = state; 
    }];  
     
   
} 
 
@end 

以上就是本文的全部內容，希望對大家的學習有所幫助。