iOS開發的22個奇谲巧技
轉載:http://www.csdn.net/article/2014-12-29/2823348-ios-dev-tricks/2
本文作者@葉孤城___,他結合自身的實踐開發經驗總結出了22個iOS開發的小技巧,以非常歡樂的語調輕松解決開發過程中所遇到的各種苦逼難題,光讀着便已忍俊不禁。
1. TableView不顯示沒内容的Cell怎麼辦?
類似于圖1,我不想讓下面的那些空顯示。很簡單,添加“self.tableView.tableFooterView = [[UIView alloc] init];”試過都說好,加完這句之後就變成了圖2的樣子。

2. 自定義了leftBarbuttonItem左滑傳回手勢失效了怎麼辦?
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]
initWithImage:img
style:UIBarButtonItemStylePlain
target:self
action:@selector(onBack:)];
self.navigationController.interactivePopGestureRecognizer.delegate = (id<UIGestureRecognizerDelegate>)self;
3. ScrollView莫名其妙不能在viewController劃到頂怎麼辦?
self.automaticallyAdjustsScrollViewInsets = NO;
4. 鍵盤事件寫得好煩躁,都想摔鍵盤了怎麼辦?
- 買個結實的鍵盤;
- 使用IQKeyboardManager(GitHub上可搜尋),用完之後腰也不疼了,腿也不酸了。
5. 為什麼我的App老是不流暢,到底哪裡出了問題?
如圖:
這個神器叫做:KMCGeigerCounter ,快去GitHub上搬運吧。
6. 怎麼在不建立一個Cell的情況下調整separaLine的位置?
_myTableView.separatorInset = UIEdgeInsetsMake(0, 100, 0, 0);
7. 怎麼點選self.view就讓鍵盤收起,需要添加一個tapGestures麼?
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[self.view endEditing:YES];
}
8. 怎麼給每個ViewController設定預設的背景圖檔?
使用基類啊,少年。
9. 想在代碼裡改在xib裡添加的layoutAttributes,但該怎麼用代碼找?
像拉Button一樣地拉你的限制,nslayoutattribute也是可以拉線的。
10. 怎麼像Safari一樣滑動的時候隐藏navigationbar?
navigationController.hidesBarsOnSwipe = Yes
11. 導覽列傳回鍵帶的title太讨厭了,怎麼讓它消失?
[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)
forBarMetrics:UIBarMetricsDefault];
12. CoreData用起來好煩,文法又臭又長怎麼辦?
MagicRecord
13. CollectionView怎麼實作tableview那種懸停的header?
CSStickyHeaderFlowLayout
14. 能不能隻用一個pan手勢來代替UISwipegesture的各個方向?
[cpp] view plain copy
- - (void)pan:(UIPanGestureRecognizer *)sender
- {
- typedef NS_ENUM(NSUInteger, UIPanGestureRecognizerDirection) {
- UIPanGestureRecognizerDirectionUndefined,
- UIPanGestureRecognizerDirectionUp,
- UIPanGestureRecognizerDirectionDown,
- UIPanGestureRecognizerDirectionLeft,
- UIPanGestureRecognizerDirectionRight
- };
- static UIPanGestureRecognizerDirection direction = UIPanGestureRecognizerDirectionUndefined;
- switch (sender.state) {
- case UIGestureRecognizerStateBegan: {
- if (direction == UIPanGestureRecognizerDirectionUndefined) {
- CGPoint velocity = [sender velocityInView:recognizer.view];
- BOOL isVerticalGesture = fabs(velocity.y) > fabs(velocity.x);
- if (isVerticalGesture) {
- if (velocity.y > 0) {
- direction = UIPanGestureRecognizerDirectionDown;
- } else {
- direction = UIPanGestureRecognizerDirectionUp;
- }
- }
- else {
- if (velocity.x > 0) {
- direction = UIPanGestureRecognizerDirectionRight;
- } else {
- direction = UIPanGestureRecognizerDirectionLeft;
- }
- }
- }
- break;
- }
- case UIGestureRecognizerStateChanged: {
- switch (direction) {
- case UIPanGestureRecognizerDirectionUp: {
- [self handleUpwardsGesture:sender];
- break;
- }
- case UIPanGestureRecognizerDirectionDown: {
- [self handleDownwardsGesture:sender];
- break;
- }
- case UIPanGestureRecognizerDirectionLeft: {
- [self handleLeftGesture:sender];
- break;
- }
- case UIPanGestureRecognizerDirectionRight: {
- [self handleRightGesture:sender];
- break;
- }
- default: {
- break;
- }
- }
- break;
- }
- case UIGestureRecognizerStateEnded: {
- direction = UIPanGestureRecognizerDirectionUndefined;
- break;
- }
- default:
- break;
- }
- }
15. 拉伸圖檔的時候怎麼才能讓圖檔不變形?
方法一:
[cpp] view plain copy
- UIImage *image = [[UIImage imageNamed:@"xxx"] stretchableImageWithLeftCapWidth:10 topCapHeight:10];
注:有開發者提醒這個已經棄用,現在的方法叫resizableImageWithCapInsets。
方法二,如圖:
16. 怎麼播放GIF的時候這麼卡,有沒有好點的庫?
FlipBoard出品的FLAnimatedImage太适合你了。
17. 怎麼一句話添加上拉重新整理?
使用SVPullToRefresh庫:
[cpp] view plain copy
- [tableView addPullToRefreshWithActionHandler:^{
- // prepend data to dataSource, insert cells at top of table view
- // call [tableView.pullToRefreshView stopAnimating] when done
- } position:SVPullToRefreshPositionBottom];
18. 怎麼把tableview裡Cell的小對勾顔色改成别的顔色?
[cpp] view plain copy
- _mTableView.tintColor = [UIColor redColor];
19. 本來我的statusbar是lightcontent的,結果用UIImagePickerController會導緻我的statusbar的樣式變成黑色,怎麼辦?
[cpp] view plain copy
- - (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
- {
- [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
- }
20. 怎麼把我的navigationbar弄成透明的而不是帶模糊的效果?
[cpp] view plain copy
- [self.navigationBar setBackgroundImage:[UIImage new]
- forBarMetrics:UIBarMetricsDefault];
- self.navigationBar.shadowImage = [UIImage new];
- self.navigationBar.translucent = YES;
21. 怎麼改變uitextfield placeholder的顔色和位置?
繼承uitextfield,重寫這個方法:
[cpp] view plain copy
- - (void) drawPlaceholderInRect:(CGRect)rect {
- [[UIColor blueColor] setFill];
- [self.placeholder drawInRect:rect withFont:self.font lineBreakMode:UILineBreakModeTailTruncation alignment:self.textAlignment];
- }
22. 你為什麼知道這麼多奇怪的花招?
去Stack Overflow刷問題啊,少年!
iOS開發UITableViewCell的選中時的顔色設定
1.系統預設的顔色設定
- //無色
- cell.selectionStyle = UITableViewCellSelectionStyleNone;
- //藍色
- cell.selectionStyle = UITableViewCellSelectionStyleBlue;
- //灰色
- cell.selectionStyle = UITableViewCellSelectionStyleGray;
2.自定義顔色和背景設定
改變UITableViewCell選中時背景色:
- UIColor *color = [[UIColoralloc]initWithRed:0.0green:0.0blue:0.0alpha:1];//通過RGB來定義自己的顔色
- cell.selectedBackgroundView = [[[UIView alloc] initWithFrame:cell.frame] autorelease];
- cell.selectedBackgroundView.backgroundColor = [UIColor xxxxxx];
3.自定義UITableViewCell選中時背景
- cell.selectedBackgroundView = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"cellart.png"]] autorelease];
- 還有字型顔色
- cell.textLabel.highlightedTextColor = [UIColor xxxcolor]; [cell.textLabel setTextColor:color]
4.設定tableViewCell間的分割線的顔色
- [theTableView setSeparatorColor:[UIColor xxxx ]];
5、設定cell中字型的顔色
Prettyprint代碼
- <span style="color: #888888;" class="com">// Customize the appearance of table view cells.</span><span style="color: #000000;" class="pun">-</span><span style="color: #000000;" class="pun">(</span><span style="color: #000088;" class="typ">UITableViewCell</span><span style="color: #000000;" class="pun">*)</span><span style="color: #000000;" class="pln">tableView</span><span style="color: #000000;" class="pun">:(</span><span style="color: #000088;" class="typ">UITableView</span><span style="color: #000000;" class="pun">*)</span><span style="color: #000000;" class="pln">tableView cellForRowAtIndexPath</span><span style="color: #000000;" class="pun">:(</span><span style="color: #000088;" class="typ">NSIndexPath</span><span style="color: #000000;" class="pun">*)</span><span style="color: #000000;" class="pln">indexPath
- </span><span style="color: #000000;" class="pun">{</span><span style="color: #000000;" class="pln">
- </span><span style="color: #880000;" class="kwd">if</span><span style="color: #000000;" class="pun">(</span><span style="color: #006666;" class="lit">0</span><span style="color: #000000;" class="pun">==</span><span style="color: #000000;" class="pln"> indexPath</span><span style="color: #000000;" class="pun">.</span><span style="color: #000000;" class="pln">row</span><span style="color: #000000;" class="pun">)</span><span style="color: #000000;" class="pln">
- </span><span style="color: #000000;" class="pun">{</span><span style="color: #000000;" class="pln">
- cell</span><span style="color: #000000;" class="pun">.</span><span style="color: #000000;" class="pln">textLabel</span><span style="color: #000000;" class="pun">.</span><span style="color: #000000;" class="pln">textColor </span><span style="color: #000000;" class="pun">=</span><span style="color: #000000;" class="pun">...;</span><span style="color: #000000;" class="pln">
- cell</span><span style="color: #000000;" class="pun">.</span><span style="color: #000000;" class="pln">textLabel</span><span style="color: #000000;" class="pun">.</span><span style="color: #000000;" class="pln">highlightedTextColor </span><span style="color: #000000;" class="pun">=</span><span style="color: #000000;" class="pun">...;</span><span style="color: #000000;" class="pln">
- </span><span style="color: #000000;" class="pun">}</span><span style="color: #000000;" class="pln">
- </span><span style="color: #000000;" class="pun">...</span><span style="color: #000000;" class="pun">}</span>
轉載:http://mobile.51cto.com/hot-404900.htm