iOS 處理鍵盤遮擋TextField、TextView問題

　　之前處理鍵盤遮擋問題都是在每一個控制器進行單獨處理，這樣做真的是非常的費事，今天在做項目的時候就想到自己封裝一個，記錄一下這個“跌宕起伏”的過程。

　　思路是這樣的：計算文本編輯控件Frame與鍵盤Frame，如果遮擋則移動控制器View。

　　創建控制器類：WKAvoidKeyboardViewController

　　

#import <UIKit/UIKit.h>

@interface WKAvoidKeyboardViewController : UIViewController

@property (nonatomic, strong) UITextField *editTextField;
@property (nonatomic, strong) UITextView *editTextView;

- (void)hideKeyboard:(NSNotification *)noti;
- (void)showKeyboard:(NSNotification *)noti;


@end


#import "WKAvoidKeyboardViewController.h"

#define GetOSVersion [[UIDevice currentDevice].systemVersion floatValue]

#define GetTransformDistance(Distance) (GetOSVersion < 7.1 ? Distance / 2 : Distance)

@interface WKAvoidKeyboardViewController ()<UITextFieldDelegate, UITextViewDelegate>

@end

@implementation WKAvoidKeyboardViewController
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    [self.view endEditing:YES];
}
@end

 

　　步驟1：通過通知獲取當前編輯的文本控件

//注冊通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(showKeyboard:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(hideKeyboard:) name:UIKeyboardWillHideNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textFieldBeginEditing:) name:UITextFieldTextDidBeginEditingNotification object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textFieldBeginEditing:) name:UITextViewTextDidBeginEditingNotification object:nil];

- (void)textFieldBeginEditing:(NSNotification *)noti
{
    self.editTextField = noti.object;
    self.editTextView = nil; 
}
- (void)textViewBeginEditing:(NSNotification *)noti
{
    self.editTextView = noti.object;
    self.editTextField = nil;
}

 

　　步驟2：通知獲取鍵盤高度

　　步驟3：計算是否需要移動

　　

#pragma mark - 鍵盤躲避

- (void)showKeyboard:(NSNotification *)noti
{
    self.view.transform = CGAffineTransformIdentity;
    UIView *editView = _editTextView ? _editTextView : _editTextField;
    
    CGRect tfRect = [editView.superview convertRect:editView.frame toView:self.view];
    NSValue *value = noti.userInfo[@"UIKeyboardFrameEndUserInfoKey"];
    NSLog(@"%@", value);
    CGRect keyBoardF = [value CGRectValue];
    
    CGFloat animationTime = [noti.userInfo[@"UIKeyboardAnimationDurationUserInfoKey"] floatValue];
    CGFloat _editMaxY = CGRectGetMaxY(tfRect);
    CGFloat _keyBoardMinY = CGRectGetMinY(keyBoardF);
    NSLog(@"%f %f", _editMaxY, _keyBoardMinY);
    if (_keyBoardMinY < _editMaxY) {
        CGFloat moveDistance = _editMaxY - _keyBoardMinY;
        [UIView animateWithDuration:animationTime animations:^{
            self.view.transform = CGAffineTransformTranslate(self.view.transform, 0, -moveDistance);
        }];
        
    }
}

- (void)hideKeyboard:(NSNotification *)noti
{
    //    NSLog(@"%@", noti);
    self.view.transform = CGAffineTransformIdentity;
}

　　初步試驗：UITextFiled成功，然后到了UITextView，坑爹的問題粗線了=.=， UITextViewTextDidBeginEditingNotification 發送時間是在鍵盤彈出通知之后的，導致第一次點擊TextView沒有用，點擊第二次才能產生效果。於是乎，我又開始嘗試用TextView的Delegate來做，想當然的使用的代理方法

- (void)textViewDidBeginEditing:(UITextView *)textView

- (void)textViewDidBeginEditing:(UITextView *)textView
{
    
}

　　令人失望的是textViewDidBeginEditing:方法調用依然是在鍵盤通知彈出后再調用，此時心中想的是：嗶了狗了，讓人怎么玩！還是看看其他方法吧。於是在代理方法中看到了

- (BOOL)textViewShouldBeginEditing:(UITextView *)textView

　　嘗試之后，此方法的確在鍵盤彈出前調用，大功告成，接下來就是設置代理的問題了

　　設置代理方法如下：

- (void)searchTextViewWithView:(UIView *)view
{
    for (UIView *subview in view.subviews)
    {
        if ([subview isKindOfClass:[UITextView class]]) {
            ((UITextView *)subview).delegate = self;
        }
        if ([subview isKindOfClass:[UITextField class]]) {
            ((UITextField *)subview).delegate = self;
        }
        [self searchTextViewWithView:subview];
    }
}

　　至此大功告成,使用方法：繼承WKAvoidKeyboardViewController,如果是用故事版創建的文本控件，啥都不用做，如果是用代碼創建的，則需要在ViewDidLoad中調用searchTextViewWithView方法

　　完整代碼下載地址：https://github.com/WuKongCoo1/AvoidKeyboardDemo.git