ios学习--iphone 实现下拉菜单

通过网上资料，自己借助资料写的代码，这是完全代码

//****************************************************************************

@interface DropDown1 : UIView <UITableViewDelegate,UITableViewDataSource>
{

UITableView *tv;//下拉列表

NSArray *tableArray;//下拉列表数据

UITextField *textField;//文本输入框

BOOL showList;//是否弹出下拉列表

CGFloat tabheight;//table下拉列表的高度

CGFloat frameHeight;//frame的高度

}

@property (nonatomic,retain) UITableView *tv;

@property (nonatomic,retain) NSArray *tableArray;

@property (nonatomic,retain) UITextField *textField;

@end

//****************************************************************************

@implementation DropDown1

@synthesize tv,tableArray,textField;

- (void)dealloc

{

[tv release];

[tableArray release];

[textField release];

[super dealloc];

}

-(id)initWithFrame:(CGRect)frame

{

if (frame.size.height<200) {

frameHeight = 200;

}else{

frameHeight = frame.size.height;

}

tabheight = frameHeight-30;

frame.size.height = 30.0f;

self=[super initWithFrame:frame];

if(self){

showList = NO; //默认不显示下拉框

tv = [[UITableView alloc] initWithFrame:CGRectMake(0, 30,
frame.size.width, 0)];

tv.delegate = self;

tv.dataSource = self;

tv.backgroundColor = [UIColor grayColor];

tv.separatorColor = [UIColor lightGrayColor];

tv.hidden = YES;

[self addSubview:tv];

textField = [[UITextField alloc] initWithFrame:CGRectMake(0, 0,
frame.size.width, 30)];

textField.borderStyle=UITextBorderStyleRoundedRect;//设置文本框的边框风格

[textField addTarget:self action:@selector(dropdown) forControlEvents:UIControlEventAllTouchEvents];

[self addSubview:textField];

}

return self;

}

-(void)dropdown{

[textField resignFirstResponder];

if (showList) {//如果下拉框已显示，什么都不做

return;

}else {//如果下拉框尚未显示，则进行显示

CGRect sf = self.frame;

sf.size.height = frameHeight;

//把dropdownList放到前面，防止下拉框被别的控件遮住

[self.superview bringSubviewToFront:self];

tv.hidden = NO;

showList = YES;//显示下拉框

CGRect frame = tv.frame;

frame.size.height = 0;

tv.frame = frame;

frame.size.height = tabheight;

[UIView beginAnimations:@"ResizeForKeyBoard" context:nil];

[UIView setAnimationCurve:UIViewAnimationCurveLinear];

self.frame = sf;

tv.frame = frame;

[UIView commitAnimations];

}

}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView

{

return 1;

}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

return [tableArray count];

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (cell == nil) {

cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];

}

cell.textLabel.text = [tableArray objectAtIndex:[indexPath row]];

cell.textLabel.font = [UIFont systemFontOfSize:16.0f];

cell.accessoryType = UITableViewCellAccessoryNone;

cell.selectionStyle = UITableViewCellSelectionStyleGray;

return cell;

}

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

{

return 35;

}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath

{

textField.text = [tableArray objectAtIndex:[indexPath row]];

showList = NO;

tv.hidden = YES;

CGRect sf = self.frame;

sf.size.height = 30;

self.frame = sf;

CGRect frame = tv.frame;

frame.size.height = 0;

tv.frame = frame;

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

// Return YES for supported orientations

return (interfaceOrientation == UIInterfaceOrientationPortrait);

}

@end

//****************************************************************************

上面的是实现方法，下面是使用：

DropDown1 *dd1 = [[DropDown1 alloc] initWithFrame:CGRectMake(10, 10, 140, 100)];

dd1.textField.placeholder = @"请输入联系方式";

NSArray* arr=[[NSArray alloc]initWithObjects:@"电话",@"email",@"手机",@"aaa",@"bbb",@"ccc",nil];

dd1.tableArray = arr;

[arr release];

[self.view addSubview:dd1];

[dd1 release];