IOS开发基础知识--碎片17
1:contentSize、contentInset和contentOffset区别
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480 contentInset 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
2:IOS虚拟器安装其它Simulator
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。
3:输入框中的inputaccessoryview和inputview
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; } }]; }
4:修改UISearchBar中关于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:@"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]; } } } }
还有另外一种方式：
- (BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar { searchController.searchBar.showsCancelButton = YES; UIButton *canceLBtn = [searchController.searchBar valueForKey:@"cancelButton"]; [canceLBtn setTitle:@"取消" forState:UIControlStateNormal]; [canceLBtn setTitleColor:[UIColor colorWithRed:14.0/255.0 green:180.0/255.0 blue:0.0/255.0 alpha:1.00] forState:UIControlStateNormal]; searchBar.showsCancelButton = YES; return YES; }
5:关于navigationController中增加控件时push跳转及跳回
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]; }
6:整个视图点击都对键盘进行收缩
- (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
7:针对第三方插件为mrc，而工程为arc的调用
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;
8:通知的方式实现键盘的收缩布局问题
/** * 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];
9:封装一个uivew带有按键工具栏的实例
.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
