iPhone起步-2:iPhone常用控件、UIActionSheet、UIAlertView (转)

一、UILabel

二、UIButton

常用事件：Touch Up Inside

三、UITextField

常用属性：

Text:要显示的文本。

Placeholder:指定将要在文本字段中以灰色显示的占位符文本。

Clear When Editing Begins:用户触摸此字段时是否删除字段中的值。

Text Input Traits:文本输入特征。

四、UIImageView

常用属性：

image:指定图像文件

Mode:图像在视图内部的对齐方式以及是否缩放图像以适应视图。选择任何图像缩放的选项都会潜在地增加处理开销，因此最好避开这些选项，并在导入图像之前调整好图像大小。通常Mode属性为Center。

Alpha：图像透明度。一般设置为1.0

Background:该属性继承自UIView，但它不会影响图像视图的外观，请忽略此属性。

Drawing复选框：选中Opaque表示视图后面的任何内容都不应该绘制，并且允许iPhone都绘图方法通过一些优化来加速绘图。

Clear Context Before Drawing:选中它之后，iPhone将使用透明黑色绘制控件覆盖都所有区域，然后才实际绘制控件。考虑到性能问题，并且适用情况很少，通常很少需要选中ClearContext Before Drawing。

Interaction复选框：

User Interaction Enabled:指定用户能否对此对象进行操作。

Multiple Touch：是否能够接收多点触摸事件。

五：UISlider(滑块)

常用属性：Value Changed

示例：

// 将silder的值反映到sliderLabel

- (IBAction) sliderValueChanged: (id)sender

{

　　　　UISlider *slider = (UISlider *)sender;

　　　　int progressAsInt = (int)(slider.value + 0.5f);

　　　　NSString *newText = [[NSStringalloc] initWithFormat:@"%d", progressAsInt];

　　　　sliderLabel.text = newText;

　　　　[newText release];

}

六：UISwitch(开关)

代码

// 属性on：获取开关的状态是否为on
// 方法setOn：设置开关的状态
- (IBAction) switchChanged: (id)sender
{
UISwitch *whichSwitch = (UISwitch *)sender;
BOOL setting = whichSwitch.on;
[leftSwitch setOn:setting animated:YES];
[rightSwitch setOn:setting animated:YES];
}

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七、UISegmentedControl

#define kSegmentIndex_Switches 0
#define kSegmentIndex_Button 1

- (IBAction) segmentChanged: (id)sender
{
switch ([sender selectedSegmentIndex])
{
case kSegmentIndex_Switches:
leftSwitch.hidden = NO;
rightSwitch.hidden = NO;
doSomethingButton.hidden = YES;
break;
case kSegmentIndex_Button:
leftSwitch.hidden = YES;
rightSwitch.hidden = YES;
doSomethingButton.hidden = NO;
break;

}

}

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八、UIActionSheet（操作表）和UIAlertView（警报）

UIActionSheet用于迫使用户在两个或更多选项之间进行选择都模式视图。操作表从屏幕底部弹出，显示一系列按钮供用户选择，用户只有单击了一个按钮后才能继续使用使用应用程序。

UIAlertView（警报）以蓝色圆角矩形都形式出现在屏幕的中部，警报可显示一个或多个按钮。

为了让控制器类充当操作表的委托，控制器类需要遵从UIActionSheetDelegate协议。我们通过在类声明都超类之后都尖括号中添加协议名称来实现。

@interface UntitledViewController : UIViewController
<UIActionSheetDelegate>
{
// ....
}

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// 创建操作表：
- (IBAction) buttonPressed: (id)sender
{
UIActionSheet *actionSheet = [[UIActionSheet alloc]
initWithTitle:@"Are you sure?"
delegate:self
cancelButtonTitle:@"Cancel"
destructiveButtonTitle:@"Yes,I'm sure."
otherButtonTitles:nil];

[actionSheet showInView:self.view];
[actionSheet release];
}

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// 实现方法：
#pragma mark ActionSheet Delegate Methods
- (void) actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex
{

if (buttonIndex != [actionSheet cancelButtonIndex])
{
NSString *text = [[NSString alloc] initWithFormat:@"test alert"];
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:@"Something was done."
message:text
delegate:self
cancelButtonTitle:@"OK!"
otherButtonTitles:nil];
[alert show];
[alert release];
[text release];
}
}

//- (void) actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
//{
// NSLog(@"%d",buttonIndex);
//}

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示例：

视图有一个UISegmentedControl,"Switches"下有两个UISwitch

"Button"下有一个“Do Something"的UIButton

触摸"Do Something"Button时弹出UIActionSheet

触摸选择"Yes,I'm sure."时弹出 UIAlertView

//
//  UntitledViewController.h
//  Untitled
//
//  Created by Elf Sundae on 11/10/10.
//  Copyright 2010 www.cnBlogs.com/ElfSundae. All rights reserved.
//

#import <UIKit/UIKit.h>

#define kSegmentIndex_Switches		0
#define kSegmentIndex_Button		　　  1


@interface UntitledViewController : UIViewController
	<UIActionSheetDelegate>
{
	UISwitch	* leftSwitch;
	UISwitch	* rightSwitch;
	UIButton	* doSomethingButton;
}

@property (retain, nonatomic) IBOutlet UISwitch *leftSwitch;
@property (retain, nonatomic) IBOutlet UISwitch *rightSwitch;
@property (retain, nonatomic) IBOutlet UIButton *doSomethingButton;

- (IBAction) switchChanged: (id)sender;
- (IBAction) segmentChanged: (id)sender;
- (IBAction) buttonPressed: (id)sender;

@end

//
//  UntitledViewController.m
//  Untitled
//
//  Created by Elf Sundae on 11/10/10.
//  Copyright 2010 www.cnBlogs.com/ElfSundae. All rights reserved.
//

#import "UntitledViewController.h"

@implementation UntitledViewController

@synthesize leftSwitch;
@synthesize rightSwitch;
@synthesize doSomethingButton;

// 属性on：获取开关的状态是否为on
// 方法setOn：设置开关的状态
- (IBAction) switchChanged: (id)sender
{
	UISwitch *whichSwitch = (UISwitch *)sender;
	BOOL setting = whichSwitch.on;
	[leftSwitch setOn:setting animated:YES];
	[rightSwitch setOn:setting animated:YES];
}


- (IBAction) segmentChanged: (id)sender
{
	switch ([sender selectedSegmentIndex]) 
	{
		case kSegmentIndex_Switches:
			leftSwitch.hidden = NO;
			rightSwitch.hidden = NO;
			doSomethingButton.hidden = YES;
			break;
		case kSegmentIndex_Button:
			leftSwitch.hidden = YES;
			rightSwitch.hidden = YES;
			doSomethingButton.hidden = NO;
			break;		
			
	}


}


- (IBAction) buttonPressed: (id)sender
{
	UIActionSheet *actionSheet = [[UIActionSheet alloc] 
				      initWithTitle:@"Are you sure?"
				      delegate:self 
				      cancelButtonTitle:@"Cancel" 
				      destructiveButtonTitle:@"Yes,I'm sure." 
				      otherButtonTitles:nil];
	
	[actionSheet showInView:self.view];
	[actionSheet release];
}

- (void)didReceiveMemoryWarning {
	// Releases the view if it doesn't have a superview.
	[super didReceiveMemoryWarning];
	
	// Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
	// Release any retained subviews of the main view.
	// e.g. self.myOutlet = nil;
	self.leftSwitch = nil;
	self.rightSwitch = nil;
	self.doSomethingButton = nil;
	[super viewDidUnload];
}


- (void)dealloc {
	[leftSwitch release];
	[rightSwitch release];
	[doSomethingButton release];
	[super dealloc];
}


#pragma mark -
#pragma mark ActionSheet Delegate Methods
- (void) actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex
{
	
	if (buttonIndex != [actionSheet cancelButtonIndex])
	{
		NSString *text = [[NSString alloc] initWithFormat:@"test alert"];
		UIAlertView *alert = [[UIAlertView alloc] 
				      initWithTitle:@"Something was done." 
				      message:text 
				      delegate:self 
				      cancelButtonTitle:@"OK!" 
				      otherButtonTitles:nil];
		[alert show];
		[alert release];
		[text release];
	}
}

//- (void) actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
//{
//	NSLog(@"%d",buttonIndex);
//}

@end