一些小技巧

記錄下一些不常用的技巧，以防忘記，複製用。

1、獲取當前的View在Window的frame：

UIWindow * window=[[[UIApplication sharedApplication] delegate] window];  
CGRect rect=[_myButton convertRect:_myButton.bounds toView:window];

2、UIImageView 和UILabel 等一些控制項，需要加這句才能setCorn

_myLabel.layer.masksToBounds = YES;

3、手機上的沙盒路徑要加"Documents"，不然存儲寫入失敗！mac上不用！

[_myArray writeToFile:[[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"]  stringByAppendingPathComponent:@"shopCategory.plist"] atomically:YES];
 
NSArray *tempAllData = [NSArray arrayWithContentsOfFile:[[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"]  stringByAppendingPathComponent:@"shopCategory.plist"]];

4、圖片拉伸不失真，如聊天軟體對話氣泡

1）、方法1，比較老的，

UIImage *tempImage2 = [UIImage imageNamed:@"sub.png"];
tempImage2 = [tempImage2 stretchableImageWithLeftCapWidth:tempImage2.size.width/2 topCapHeight:0];

 2）、方法2，比較新的

UIImage *tempImage3 = [UIImage imageNamed:@"sub"];

CGFloat tempH = tempImage3.size.height/2;
CGFloat tempW = tempImage3.size.width/2;
    
UIEdgeInsets tempEdg = UIEdgeInsetsMake(tempH, tempW, tempH, tempW);
    
tempImage3 = [tempImage3 resizableImageWithCapInsets:tempEdg resizingMode:UIImageResizingModeStretch];

 5、視頻截取縮略圖，其中CMTimeMakeWithSeconds(5,1)，調整截圖幀數/秒數，一般不用特意去修改，不做參數傳入，除非片頭一段時間都一樣的視頻。

#import <AVFoundation/AVFoundation.h>

-(UIImage *)getThumbnailImage:(NSString *)videoURL
{
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:[NSURL fileURLWithPath:videoURL] options:nil];
    
    AVAssetImageGenerator *gen = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    
    gen.appliesPreferredTrackTransform = YES;
    //控制截取時間
    CMTime time = CMTimeMakeWithSeconds(5, 1);
    
    NSError *error = nil;
    
    CMTime actualTime;
    
    CGImageRef image = [gen copyCGImageAtTime:time actualTime:&actualTime error:&error];
    
    UIImage *thumb = [[UIImage alloc] initWithCGImage:image];
    
    CGImageRelease(image);
    
    return thumb;
}

 6、cell下劃線左邊頂住屏幕左邊。

cell.preservesSuperviewLayoutMargins = NO;
cell.layoutMargins = UIEdgeInsetsZero;
cell.separatorInset = UIEdgeInsetsZero;

7、去除xcode8冗餘信息，雖然已經記住了。

OS_ACTIVITY_MODE    disable

8、播放音頻

1）工程內音頻

1-1)、獲取音頻路徑

NSString *path = [[NSBundle mainBundle] pathForResource:@"shakebell" ofType:@"wav"];
    
NSURL *url = [NSURL fileURLWithPath:path];

 1-2)、創建音頻播放ID

SystemSoundID soundID;
AudioServicesCreateSystemSoundID((__bridge CFURLRef _Nonnull)(url), &soundID);

1-3)、Play

AudioServicesPlaySystemSound(soundID);

2）系統音頻，參數為1000-1351，具體查表，如1007為“sms-received1”

AudioServicesPlaySystemSound(1007);

9、字體自適應

1）、固定的Frame，自適應Font大小，如數量增減，1和1000。

[label1 setAdjustsFontSizeToFitWidth:YES];

2）、固定的Font，自適應Frame，用於信息類顯示

[label2 sizeToFit]; 

3）、固定的Font，獲取自適應Frame值，反過來設置Label的Frame，用於信息類顯示。這裡的100是等下設置Label的width，也是返回的rect.frame.size.width

CGRect rect = [templabel.text boundingRectWithSize:CGSizeMake(100, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName:templabel.font} context:nil];

10、AFNetworking 檢測網路連接狀態

[[AFNetworkReachabilityManager sharedManager]startMonitoring];

[[AFNetworkReachabilityManager sharedManager]setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        NSLog(@"%ld",status);
    }];

11、編輯相關

1）鍵盤事件通知

1-1）、彈出鍵盤可能蓋住TextField。監聽鍵盤的通知

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(moveView:) name:UIKeyboardDidChangeFrameNotification object:nil];

1-2）、moveView方法里接收通知，tempTime是鍵盤動畫時間，tempY是鍵盤當前的y軸位置。（接著要移動評論框或者移動後面的ScrollView都可以）

CGFloat tempTime = [[noti.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue];
CGFloat tempY = [[noti.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey]CGRectValue].origin.y

//重置約束條件
//self.theBottomSpace.constant = ？;

[UIView animateWithDuration:duration animations:^{
        //更新約束
        [self.view layoutIfNeeded];

    }];

2）dealloc記得移除

[[NSNotificationCenter defaultCenter]removeObserver:self];

3）touchesBegan:withEvent && scrollViewDidScroll -->屏幕點擊&&屏幕滑動要取消編輯狀態

[self.view endEditing:YES];

12、上傳圖片（頭像）

1-1）、把Image打成NSData

NSData *imagedata = UIImageJPEGRepresentation(tempImage, 1.0);

1-2）、AFNetworking的POST方法填如下。formData：POST方法里的Block參數，name：跟伺服器有關，filename：隨意填，mimeType：就image/jpg。

[formData appendPartWithFileData:imagedata name:@"imgFile" fileName:@"idontcare.jpg" mimeType:@"image/jpg"];

13、強制佈局

[self.view layoutIfNeeded];

14、圖片雙擊縮放

1)scrollView才可以縮放，所以要把ImageView加在scrollView，給scrollView（這裡的 self ）添加手勢識別。要設最大/小縮放比例！

UITapGestureRecognizer *imageTwoTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(twoTapAction:)];

imageTwoTap.numberOfTapsRequired = 2;

[self addGestureRecognizer: imageTwoTap];

2)第一次點哪放大哪，第二次恢複原來大小

#define SCALE_WIDTH  60    		//要放大的局部寬度大小
#define SCALE_HEIGHT 60    		//要放大的局部高度大小

-(void)twoTapAction:(UITapGestureRecognizer *)tempTap
{
    if (self.zoomScale != 1.0)
    {
        [self setZoomScale:1.0 animated:YES];
    }
    else
    {
        CGPoint tempPoint = [tempTap locationInView:self];
        [self zoomToRect:CGRectMake(tempPoint.x-SCALE_WIDTH/2, tempPoint.y-SCALE_HEIGHT/2, SCALE_WIDTH, SCALE_HEIGHT) animated:YES];
    }
}