1:contentSize、contentInset和contentOffset區別

contentSize 是scrollview中的一個屬性，它代表scrollview中的可顯示區域，假如有一個scrollview，它的frame為(0,0,320,480),而它的contentSize為(320,960).也就是說，這個scrollview整個內容的大小為(320,960),要通過上下滑動scrollview來查看(320,480)後的內容。

contentOffset 是scrollview當前顯示區域頂點相對於frame頂點的偏移量，比如上個例子你拉到最下面，contentoffset就是(0 ,-480)，也就是y偏移了480

contentInset 是scrollview中contentView.frame.origin與scrollview.frame.origin的關系，比如contentView的frame為(0,30,320,480),那麼contentInset則為(0, 30),它也可以設置上下左右


2:IOS虛擬器安裝其它Simulator

下載後的dmg安裝.這裡主要以iOS7.0模擬器的離線安裝為例進行說明，其他版本以此類推：

下載ios_7_0_simulator.dmg後打開dmg文件，可以看到安裝包iPhoneSimulatorSDK7_0.pkg，使用安裝器安裝此安裝包，默認會安裝在所選分區的/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.0.sdk目錄下，完全退出Xcode後將剛才安裝的iPhoneSimulator7.0.sdk整個目錄復制或移動到/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs目錄下即可，(Xcode.app右鍵可以"顯示包內容“)重新啟動Xcode一般就可以使用相應版本的模擬器進行開發和調試了。

離線安裝還有一個簡單的辦法就是將以前安裝過的舊版本的Xcode如Xcode5.0.2下面已經安裝好了的iOS模擬器直接復制過來使用，目錄位置都一樣，都是在Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs裡面。這樣就不用再下載離線安裝包了。


3:輸入框中的inputaccessoryview和inputview

UITextFields和UITextView有一個inputAccessoryView的屬性，當你想在鍵盤上展示一個自定義的view時，你就可以設置該屬性。你設置的view就會自動和鍵盤keyboard一起顯示了。需要注意的是，你所自定義的view既不應該處在其他的視圖層裡，也不應該成為其他視圖的子視圖。其實也就是說，你所自定義的view只需要賦給屬性inputAccessoryView就可以了，不要再做其他多余的操作。

inputview則是鍵盤視圖，當其為nil時則彈出的是系統默認的鍵盤；

實例一(給鍵盤上方設置一個工具條的方式)：

- (void)createKeyboardTool
{
    keyboardTool = [[UIToolbar alloc] initWithFrame: CGRectMake(kZero, kZero, kScreenW, 44.0f)];
    NSMutableArray *myToolBarItems = [NSMutableArray array];

　　//創建鍵盤工具條上面的按鈕,並設置點擊事件
    UIBarButtonItem *cancelBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemReply target:self action:@selector(cancelAction)];
    UIBarButtonItem *space = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:@selector(saveAction)];
    UIBarButtonItem *saveBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(saveAction)];
    
    [myToolBarItems addObject:cancelBtn];
    [myToolBarItems addObject:space];
    [myToolBarItems addObject:saveBtn];
    keyboardTool.items = myToolBarItems;
}

//inputAccessoryView:設置鍵盤頂部顯示的工具條;inputView:自定義鍵盤
    commentTextView = [[UITextView alloc]initWithFrame:CGRectMake(kZero, kZero, kScreenW, 200)];
    [commentTextView becomeFirstResponder];
    commentTextView.inputAccessoryView = keyboardTool;


實例二(修改鍵盤視圖，進行切換自定義視圖跟系統自帶視圖)：


/**
 *  切換鍵盤
 */
- (void)switchKeyboard
{
    // self.textView.inputView == nil : 使用的是系統自帶的鍵盤
    if (self.textView.inputView == nil) {
        // 切換為自定義的表情鍵盤 emtionKeyboard為一個視圖
        self.textView.inputView = self.emotionKeyboard;
        // 顯示鍵盤按鈕
        self.toolbar.showKeyboardButton = YES;
    } else { 
        // 切換為系統自帶的鍵盤
        self.textView.inputView = nil;
        // 顯示表情按鈕
        self.toolbar.showKeyboardButton = NO;
    }
    // 開始切換鍵盤 這個是為固定用的
    self.switchingKeybaord = YES;    
    // 退出鍵盤
    [self.textView endEditing:YES];    
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        // 彈出鍵盤,讓其慢點實現 
        [self.textView becomeFirstResponder];        
        // 結束切換鍵盤
        self.switchingKeybaord = NO;
    });
}


/**
 * 鍵盤的frame發生改變時調用（顯示、隱藏等）
 */
- (void)keyboardWillChangeFrame:(NSNotification *)notification
{
    // 如果正在切換鍵盤，就不要執行後面的代碼
    if (self.switchingKeybaord) return;
    
    NSDictionary *userInfo = notification.userInfo;
    // 動畫的持續時間
    double duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    // 鍵盤的frame
    CGRect keyboardF = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    
    // 執行動畫
    [UIView animateWithDuration:duration animations:^{
        // 工具條的Y值 == 鍵盤的Y值 - 工具條的高度
        if (keyboardF.origin.y > self.view.height) { // 鍵盤的Y值已經遠遠超過了控制器view的高度
            self.toolbar.y = self.view.height - self.toolbar.height;
        } else {
            self.toolbar.y = keyboardF.origin.y - self.toolbar.height;
        }
    }];
}


4:修改UISearchBar中關於cannel取消的文字

-(UISearchBar *)mySearchBar
{
    if (_mySearchBar==nil) {
        _mySearchBar=[[UISearchBar alloc]init];
        _mySearchBar.showsCancelButton=YES;
        _mySearchBar.delegate=self;
        [_mySearchBar sizeToFit];
        [_mySearchBar setPlaceholder:@"請輸入"];
        [_mySearchBar setY:20];
        
        //處理cannel的文字顯示
        for (id item in [_mySearchBar subviews]) {
            for(id cc in [item subviews])
            {
                if ([cc isKindOfClass:[UIButton class]]) {
                    UIButton *btn=(UIButton *)cc;
                    [btn setTitle:@"取消" forState:UIControlStateNormal];
                }
            }
        }
    }
    return _mySearchBar;
}

如果是獲得瞧點才顯示出取消可以在這個委托裡面進行設置:

/**
 *  @author wujunyang, 15-06-24 11:06:44
 *
 *  @brief  修改cancel的顯示文字 必先把showscancelButton設置為yes
 *  @param searchBar <#searchBar description#>
 */
- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
{
    searchBar.showsCancelButton=YES;
    for (id item in [searchBar subviews]) {
        for(id cc in [item subviews])
        {
        if ([cc isKindOfClass:[UIButton class]]) {
            UIButton *btn=(UIButton *)cc;
            [btn setTitle:@"取消" forState:UIControlStateNormal];
        }
        }
    }
}


5:關於navigationController中增加控件時push跳轉及跳回

在子頁navigationController增加控件,回跳時它是沒辦法自個銷除，所以要手動增加一個銷除nav所增加的控件，否則子頁的那個控件會被重疊顯示在父頁的nav上；如下一個實例：

在viewDidLoad裡
//加載控件
    [self.navigationController.view addSubview:self.mySearchBar];

(void)viewWillDisappear:(BOOL)animated {
    //這句也可以寫在回跳前
    [self.mySearchBar removeFromSuperview];
    [super viewWillDisappear:animated];
}
6:整個視圖點擊都對鍵盤進行收縮

- (void)viewDidLoad {
    [super viewDidLoad];
    UITapGestureRecognizer *tapGr=[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(viewTapped:)];
    //如果沒有這句在view中的Button等可能無法觸發ToucheUpInside事件
    tapGr.cancelsTouchesInView=NO;
    [self.view addGestureRecognizer:tapGr];
}
- (IBAction)BtnAction:(id)sender {
    NSLog(@"%@",self.myTextField.text);
}
-(void)viewTapped:(UITapGestureRecognizer *)tapGr
{
    [self.myTextField resignFirstResponder];
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}
@end
7:針對第三方插件為mrc，而工程為arc的調用

對第三方插件的.m文件進行設置，工程targets-build phases－compile sources 設置-fno-objc-arc

有些是雙星如 PLTexture **previewTextures; 
在arc下面則要修改成：PLTexture * __unsafe_unretained *previewTextures;
8:通知的方式實現鍵盤的收縮布局問題

/**
 *  添加工具條
 */
- (void)setupToolbar
{
    // 1.添加工具條
    IWComposeToolbar *toolbar = [[IWComposeToolbar alloc] init];
    toolbar.delegate = self;
    CGFloat toolbarH = 35;
    CGFloat toolbarW = self.view.width;
    CGFloat toolbarY = self.view.height - toolbarH;
    toolbar.frame = CGRectMake(0, toolbarY, toolbarW, toolbarH);
    [self.view addSubview:toolbar];
    self.toolbar = toolbar;
    
    // 2.監聽鍵盤的彈出和隱藏
    // 鍵盤的frame(位置)即將改變, 就會發出UIKeyboardWillChangeFrameNotification
    // 鍵盤即將彈出, 就會發出UIKeyboardWillShowNotification
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    // 鍵盤即將隱藏, 就會發出UIKeyboardWillHideNotification
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}


#pragma mark - 鍵盤處理
/**
 *  鍵盤即將隱藏
 */
- (void)keyboardWillHide:(NSNotification *)note
{
    // 1.鍵盤彈出需要的時間
    CGFloat duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    
    // 2.動畫
    [UIView animateWithDuration:duration animations:^{
        self.toolbar.transform = CGAffineTransformIdentity;
    }];
}

/**
 *  鍵盤即將彈出
 */
- (void)keyboardWillShow:(NSNotification *)note
{
    // 1.鍵盤彈出需要的時間
    CGFloat duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    
    // 2.動畫
    [UIView animateWithDuration:duration animations:^{
        // 取出鍵盤高度
        CGRect keyboardF = [note.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
        CGFloat keyboardH = keyboardF.size.height;
        self.toolbar.transform = CGAffineTransformMakeTranslation(0, - keyboardH);
    }];
}

//通知要銷掉
- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

注意：[self.textView resignFirstResponder];放棄瞧點
還有可以監聽輸入內容的變化：    // 2.監聽textView文字的改變
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textChange) name:UITextViewTextDidChangeNotification object:textView];
9:封裝一個uivew帶有按鍵工具欄的實例

.h文件內容：

#import <UIKit/UIKit.h>

@class IWComposeToolbar;

typedef enum {
    IWComposeToolbarButtonTypeCamera,
    IWComposeToolbarButtonTypePicture,
    IWComposeToolbarButtonTypeMention,
    IWComposeToolbarButtonTypeTrend,
    IWComposeToolbarButtonTypeEmotion
} IWComposeToolbarButtonType;

@protocol IWComposeToolbarDelegate <NSObject>
@optional
- (void)composeToolbar:(IWComposeToolbar *)toolbar didClickButton:(IWComposeToolbarButtonType)butonType;
@end

@interface IWComposeToolbar : UIView
@property (weak, nonatomic) id<IWComposeToolbarDelegate> delegate;
@end


.m文件內容：

#import "IWComposeToolbar.h"

@implementation IWComposeToolbar

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // 1.設置背景
        self.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageWithName:@"compose_toolbar_background"]];
        
        // 2.添加按鈕
        [self addButtonWithIcon:@"compose_camerabutton_background" highIcon:@"compose_camerabutton_background_highlighted" tag:IWComposeToolbarButtonTypeCamera];
        [self addButtonWithIcon:@"compose_toolbar_picture" highIcon:@"compose_toolbar_picture_highlighted" tag:IWComposeToolbarButtonTypePicture];
        [self addButtonWithIcon:@"compose_mentionbutton_background" highIcon:@"compose_mentionbutton_background_highlighted" tag:IWComposeToolbarButtonTypeMention];
        [self addButtonWithIcon:@"compose_trendbutton_background" highIcon:@"compose_trendbutton_background_highlighted" tag:IWComposeToolbarButtonTypeTrend];
        [self addButtonWithIcon:@"compose_emoticonbutton_background" highIcon:@"compose_emoticonbutton_background_highlighted" tag:IWComposeToolbarButtonTypeEmotion];
    }
    return self;
}

- (void)addButtonWithIcon:(NSString *)icon highIcon:(NSString *)highIcon tag:(IWComposeToolbarButtonType)tag
{
    UIButton *button = [[UIButton alloc] init];
    button.tag = tag;
    ;
     forState:UIControlStateNormal];
     forState:UIControlStateHighlighted];
    [self addSubview:button];
}

/**
 *  監聽按鈕點擊
 */
- (void)buttonClick:(UIButton *)button
{
    if ([self.delegate respondsToSelector:@selector(composeToolbar:didClickButton:)]) {
        [self.delegate composeToolbar:self didClickButton:button.tag];
    }
}

- (void)layoutSubviews
{
    [super layoutSubviews];
    
    int count = self.subviews.count;
    CGFloat buttonW = self.width / count;
    CGFloat buttonH = self.height;
    for (int i = 0; i<count; i++) {
        UIButton *button = self.subviews[i];
        CGFloat buttonX = buttonW * i;
        button.frame = CGRectMake(buttonX, 0, buttonW, buttonH);
    }
}

@end