IOS开发基础知识--碎片17

contentSize 是scrollview中的一个属性，它代表scrollview中的可显示区域，假如有一个scrollview，它的frame为(0,0,320,480),而它的contentSize为(320,960).也就是说，这个scrollview整个内容的大小为(320,960),要通过上下滑动scrollview来查看(320,480)后的内容。contentOffset 是scrollview当前显示区域顶点相对于frame顶点的偏移量，比如上个例子你拉到最下面，contentoffset就是(0 ,-480)，也就是y偏移了480contentInset 是scrollview中contentView.frame.origin与scrollview.frame.origin的关系，比如contentView的frame为(0,30,320,480),那么contentInset则为(0, 30),它也可以设置上下左右

下载后的dmg安装.这里主要以iOS7.0模拟器的离线安装为例进行说明，其他版本以此类推：下载ios_7_0_simulator.dmg后打开dmg文件，可以看到安装包iphoneSimulatorSDK7_0.pkg，使用安装器安装此安装包，默认会安装在所选分区的/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.0.sdk目录下，完全退出Xcode后将刚才安装的iPhoneSimulator7.0.sdk整个目录复制或移动到/applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs目录下即可，(Xcode.app右键可以"显示包内容“)重新启动Xcode一般就可以使用相应版本的模拟器进行开发和调试了。离线安装还有一个简单的办法就是将以前安装过的旧版本的Xcode如Xcode5.0.2下面已经安装好了的iOS模拟器直接复制过来使用，目录位置都一样，都是在Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs里面。这样就不用再下载离线安装包了。

UITextFields和UITextView有一个inputAccessoryView的属性，当你想在键盘上展示一个自定义的view时，你就可以设置该属性。你设置的view就会自动和键盘keyboard一起显示了。需要注意的是，你所自定义的view既不应该处在其他的视图层里，也不应该成为其他视图的子视图。其实也就是说，你所自定义的view只需要赋给属性inputAccessoryView就可以了，不要再做其他多余的操作。inputview则是键盘视图，当其为nil时则弹出的是系统默认的键盘；实例一(给键盘上方设置一个工具条的方式)：- (void)createKeyboardTool{    keyboardTool = [[UIToolbar alloc] initWithFrame: CGRectMake(kZero, kZero, kScreenW, 44.0f)];    NSMutableArray *myToolBarItems = [NSMutableArray array];　　//创建键盘工具条上面的按钮,并设置点击事件    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:设置键盘顶部显示的工具条;inputView:自定义键盘    commentTextView = [[UITextView alloc]initWithFrame:CGRectMake(kZero, kZero, kScreenW, 200)];    [commentTextView becomeFirstResponder];    commentTextView.inputAccessoryView = keyboardTool;实例二(修改键盘视图，进行切换自定义视图跟系统自带视图)：/** *  切换键盘 */- (void)switchKeyboard{    // self.textView.inputView == nil : 使用的是系统自带的键盘    if (self.textView.inputView == nil) {        // 切换为自定义的表情键盘 emtionKeyboard为一个视图        self.textView.inputView = self.emotionKeyboard;        // 显示键盘按钮        self.toolbar.showKeyboardButton = YES;    } else {         // 切换为系统自带的键盘        self.textView.inputView = nil;        // 显示表情按钮        self.toolbar.showKeyboardButton = NO;    }    // 开始切换键盘 这个是为固定用的    self.switchingKeybaord = YES;        // 退出键盘    [self.textView endEditing:YES];        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{        // 弹出键盘,让其慢点实现         [self.textView becomeFirstResponder];                // 结束切换键盘        self.switchingKeybaord = NO;    });}/** * 键盘的frame发生改变时调用（显示、隐藏等） */- (void)keyboardWillChangeFrame:(NSNotification *)notification{    // 如果正在切换键盘，就不要执行后面的代码    if (self.switchingKeybaord) return;        NSDictionary *userInfo = notification.userInfo;    // 动画的持续时间    double duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];    // 键盘的frame    CGRect keyboardF = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];        // 执行动画    [UIView animateWithDuration:duration animations:^{        // 工具条的Y值 == 键盘的Y值 - 工具条的高度        if (keyboardF.origin.y > self.view.height) { // 键盘的Y值已经远远超过了控制器view的高度            self.toolbar.y = self.view.height - self.toolbar.height;        } else {            self.toolbar.y = keyboardF.origin.y - self.toolbar.height;        }    }];}

-(UISearchBar *)mySearchBar{    if (_mySearchBar==nil) {        _mySearchBar=[[UISearchBar alloc]init];        _mySearchBar.showsCancelButton=YES;        _mySearchBar.delegate=self;        [_mySearchBar sizeToFit];        [_mySearchBar setPlaceholder:@"请输入"];        [_mySearchBar setY:20];                //处理cannel的文字显示        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;}如果是获得瞧点才显示出取消可以在这个委托里面进行设置:/** *  @author wujunyang, 15-06-24 11:06:44 * *  @brief  修改cancel的显示文字 必先把showscancelButton设置为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];        }        }    }}

在子页navigationController增加控件,回跳时它是没办法自个销除，所以要手动增加一个销除nav所增加的控件，否则子页的那个控件会被重叠显示在父页的nav上；如下一个实例：在viewDidLoad里//加载控件    [self.navigationController.view addSubview:self.mySearchBar];(void)viewWillDisappear:(BOOL)animated {    //这句也可以写在回跳前    [self.mySearchBar removeFromSuperview];    [super viewWillDisappear:animated];}

- (void)viewDidLoad {    [super viewDidLoad];    UITapGestureRecognizer *tapGr=[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(viewTapped:)];    //如果没有这句在view中的Button等可能无法触发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

对第三方插件的.m文件进行设置，工程targets-build phases－compile sources 设置-fno-objc-arc有些是双星如 PLTexture **PReviewTextures; 在arc下面则要修改成：PLTexture * __unsafe_unretained *previewTextures;

/** *  添加工具条 */- (void)setupToolbar{    // 1.添加工具条    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.监听键盘的弹出和隐藏    // 键盘的frame(位置)即将改变, 就会发出UIKeyboardWillChangeFrameNotification    // 键盘即将弹出, 就会发出UIKeyboardWillShowNotification    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];    // 键盘即将隐藏, 就会发出UIKeyboardWillHideNotification    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];}#pragma mark - 键盘处理/** *  键盘即将隐藏 */- (void)keyboardWillHide:(NSNotification *)note{    // 1.键盘弹出需要的时间    CGFloat duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];        // 2.动画    [UIView animateWithDuration:duration animations:^{        self.toolbar.transform = CGAffineTransformIdentity;    }];}/** *  键盘即将弹出 */- (void)keyboardWillShow:(NSNotification *)note{    // 1.键盘弹出需要的时间    CGFloat duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];        // 2.动画    [UIView animateWithDuration:duration animations:^{        // 取出键盘高度        CGRect keyboardF = [note.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];        CGFloat keyboardH = keyboardF.size.height;        self.toolbar.transform = CGAffineTransformMakeTranslation(0, - keyboardH);    }];}//通知要销掉- (void)dealloc{    [[NSNotificationCenter defaultCenter] removeObserver:self];}注意：[self.textView resignFirstResponder];放弃瞧点还有可以监听输入内容的变化：    // 2.监听textView文字的改变    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textChange) name:UITextViewTextDidChangeNotification object:textView];

.h文件内容：#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文件内容：#import "IWComposeToolbar.h"@implementation IWComposeToolbar- (id)initWithFrame:(CGRect)frame{    self = [super initWithFrame:frame];    if (self) {        // 1.设置背景        self.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageWithName:@"compose_toolbar_background"]];                // 2.添加按钮        [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;    [button addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];    [button setImage:[UIImage imageWithName:icon] forState:UIControlStateNormal];    [button setImage:[UIImage imageWithName:highIcon] forState:UIControlStateHighlighted];    [self addSubview:button];}/** *  监听按钮点击 */- (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