［IOS］textField被虚拟键盘挡住解决方法

转载自：http://www.cnblogs.com/iphone520/archive/2011/10/11/2207616.html

      

经常会遇到以下情况，textField被虚拟键盘挡住的情况，解决。

RootViewController.h  中：

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController<UITextFieldDelegate> {

    UITextField *textField1;
    UITextField *textField2;
    
}
@property (nonatomic,retain) UITextField *textField1;
@property (nonatomic ,retain) UITextField *textField2;

-(IBAction)backgroundTap:(id)sender;


@end

RootViewController.m  中：

#import "RootViewController.h"

@implementation RootViewController
@synthesize textField1;
@synthesize textField2;

// The designated initializer.  Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
/*
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization.
    }
    return self;
}
*/

/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
    
    UIView *back = [[UIView alloc] initWithFrame:[[UIScreen mainScreen]bounds]];
    back.backgroundColor = [UIColor grayColor];
    self.view = back;
    [back release];
}
*/

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
    
    UIControl *_back = [[UIControl alloc] initWithFrame:self.view.frame];
    _back.backgroundColor = [UIColor grayColor];
    self.view = _back;
    [_back release];
    [(UIControl *)self.view addTarget:self action:@selector(backgroundTap:) forControlEvents:UIControlEventTouchDown];
    
    
    textField1 = [[UITextField alloc] initWithFrame:CGRectMake(20, 300, 200, 30)];
    textField1.backgroundColor = [UIColor clearColor];
    textField1.borderStyle = UITextBorderStyleRoundedRect;
    textField1.textColor = [UIColor redColor];
    textField1.delegate = self;
    [self.view addSubview:textField1];
    
    textField2 = [[UITextField alloc] initWithFrame:CGRectMake(20, 30, 200, 30)];
    textField2.backgroundColor = [UIColor clearColor];
    textField2.borderStyle = UITextBorderStyleRoundedRect;
    textField2.textColor = [UIColor redColor];
    textField2.delegate = self;
    [self.view addSubview:textField2];
    
    
}

#pragma mark -
#pragma mark 解决虚拟键盘挡住UITextField的方法
- (void)keyboardWillShow:(NSNotification *)noti
{       
    //键盘输入的界面调整       
    //键盘的高度
    float height = 216.0;               
    CGRect frame = self.view.frame;       
    frame.size = CGSizeMake(frame.size.width, frame.size.height - height);       
    [UIView beginAnimations:@"Curl"context:nil];//动画开始         
    [UIView setAnimationDuration:0.30];          
    [UIView setAnimationDelegate:self];         
    [self.view setFrame:frame];        
    [UIView commitAnimations];
}

-(BOOL)textFieldShouldReturn:(UITextField *)textField
{       
    // When the user presses return, take focus away from the text field so that the keyboard is dismissed.       
    NSTimeInterval animationDuration = 0.30f;       
    [UIView beginAnimations:@"ResizeForKeyboard" context:nil];       
    [UIView setAnimationDuration:animationDuration];       
    CGRect rect = CGRectMake(0.0f, 20.0f, self.view.frame.size.width, self.view.frame.size.height);       
    self.view.frame = rect;
    [UIView commitAnimations];
    [textField resignFirstResponder];
    return YES;       
}

- (void)textFieldDidBeginEditing:(UITextField *)textField
{       
    CGRect frame = textField.frame;
    int offset = frame.origin.y + 32 - (self.view.frame.size.height - 216.0);//键盘高度216
    NSTimeInterval animationDuration = 0.30f;               
    [UIView beginAnimations:@"ResizeForKeyBoard" context:nil];               
    [UIView setAnimationDuration:animationDuration];
    float width = self.view.frame.size.width;               
    float height = self.view.frame.size.height;       
    if(offset > 0)
    {
        CGRect rect = CGRectMake(0.0f, -offset,width,height);               
        self.view.frame = rect;       
    }       
    [UIView commitAnimations];               
}
#pragma mark -

#pragma mark -
#pragma mark 触摸背景来关闭虚拟键盘
-(IBAction)backgroundTap:(id)sender
{
    // When the user presses return, take focus away from the text field so that the keyboard is dismissed.       
    NSTimeInterval animationDuration = 0.30f;       
    [UIView beginAnimations:@"ResizeForKeyboard" context:nil];       
    [UIView setAnimationDuration:animationDuration];       
    CGRect rect = CGRectMake(0.0f, 20.0f, self.view.frame.size.width, self.view.frame.size.height);       
    self.view.frame = rect;
    [UIView commitAnimations];
    
    [textField1 resignFirstResponder];
    [textField2 resignFirstResponder];
}

#pragma mark -

/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations.
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/

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


- (void)dealloc {
    [textField1 release];
    [textField2 release];
    [super dealloc];
}

RootViewController.m 中的backgroundTap:方法，用来实现触摸背景来关闭虚拟键盘。

这个方法用的时候首先把RootViewController上的view改成UIControl，然后通过UIControl的事件UIControlEventTouchDown来触发上面的方法backgroundTap: 。

注意下面的代码：

UIControl *_back = [[UIControl alloc] initWithFrame:self.view.frame];
    _back.backgroundColor = [UIColor grayColor];
    self.view = _back;
    [_back release];
    [(UIControl *)self.view addTarget:self action:@selector(backgroundTap:) forControlEvents:UIControlEventTouchDown];

解决textField被键盘挡住的问题的方法有三个：

- (void)keyboardWillShow:(NSNotification *)noti;//调整虚拟键盘与self.view之间的关系。

-(BOOL)textFieldShouldReturn:(UITextField *)textField;//触摸键盘上的return键时关闭虚拟键盘

- (void)textFieldDidBeginEditing:(UITextField *)textField;//当编辑文本的时候，如果虚拟键盘挡住了textField，整个view就会向上移动。移动范围是一个键盘的高度216。