IOS小技巧

淡淡的烟草味﹌ 2022-08-06 02:09 223阅读 0赞

1.通过下面方式可以获取图片的像素颜色点：  
\- (void\*)getImageData:(UIImage\*)image  
\{  
void\* imageData;  
if (imageData == NULL)  
imageData = malloc(4 \* image.size.width \* image.size.height);  
  
CGColorSpaceRef cref = CGColorSpaceCreateDeviceRGB();  
CGContextRef gc = CGBitmapContextCreate(imageData,  
image.size.width,image.size.height,  
8,image.size.width\*4,  
cref,kCGImageAlphaPremultipliedFirst);  
CGColorSpaceRelease(cref);  
UIGraphicsPushContext(gc);  
  
\[image drawAtPoint:CGPointMake(0.0f, 0.0f)\];  
  
UIGraphicsPopContext();  
CGContextRelease(gc);  
return imageData;  
\}

2.UILabel和UITextField的小应用

UILabel \*LY\_Label = \[\[UILabel alloc\] initWithFrame:CGRectMake(60, 180, 60, 30)\];  
\[self.view addSubview:LY\_Label\];  
LY\_Label.backgroundColor = \[UIColor clearColor\];  
LY\_Label.text = @"密 码";  
LY\_Label.font= \[UIFont fontWithName:@"zapfino" size:(15.0f)\]; //字体设置  
\[\[LY\_Label layer\] setBorderWidth:2.0f\]; //边框设置  
  
UITextField \*LY\_Text = \[\[UITextField alloc\] initWithFrame:CGRectMake(143, 180, 80, 30) \];  
\[self.view addSubview:LY\_Text\];  
LY\_Text.backgroundColor = \[UIColor whiteColor\];  
\[LY\_Text setBorderStyle:UITextBorderStyleLine\]; //边框设置  
LY\_Text.placeholder = @"password"; //默认显示的字  
LY\_Text.font = \[UIFont fontWithName:@"helvetica" size:12\]; //字体和大小设置  
LY\_Text.textColor = \[UIColor redColor\]; //设置字体的颜色  
LY\_Text.clearButtonMode = UITextFieldViewModeWhileEditing; //清空功能x  
LY\_Text.returnKeyType = UIReturnKeyDone; //键盘有done

LY\_Text.secureTextEntry = YES; //密码输入时

\[LY\_Text becomeFirstResponder\]; //自动弹出软键盘

LY\_Text.delegate = self; //托管

3.navigatrionbar 导航条设置颜色

UINavigationBar \*bar = \[\[UINavigationBar alloc\] initWithFrame:CGRectMake(0, 0, 320,44)\];

bar.tintColor = \[UIColor blackColor\];

UINavigationItem \*barItem = \[\[UINavigationItem alloc\] initWithTitle:@""\];

\[bar setItems:\[NSArray arrayWithObjects:barItem,nil\]\];

\[baseView addSubview:bar\];

4.AnnotationView的一些操作

\- (MKAnnotationView \*)mapView:(MKMapView \*)aMapView viewForAnnotation:(id <MKAnnotation>)annotation \{ if(!\[annotation isKindOfClass:\[MyAnnotation class\]\]) //Don't mess user location return nil; MKAnnotationView \*annotationView = \[aMapView dequeueReusableAnnotationViewWithIdentifier:@"spot"\]; if(!annotationView) \{ annotationView = \[\[MKAnnotationView alloc\] initWithAnnotation:annotation reuseIdentifier:@"spot"\]; annotationView.rightCalloutAccessoryView = \[UIButton buttonWithType:UIButtonTypeDetailDisclosure\]; \[(UIButton \*)annotationView.rightCalloutAccessoryView addTarget:self action:@selector(openSpot:) forControlEvents:UIControlEventTouchUpInside\]; annotationView.enabled = YES; annotationView.canShowCallout = YES; annotationView.centerOffset =CGPointMake(7,-15); annotationView.calloutOffset = CGPointMake(-8,0); \} // Setup annotation view annotationView.image = \[UIImage imageNamed:@"pinYellow.png"\];// Or whatever return annotationView; \}

\- (MKAnnotationView \*)mapView:(MKMapView \*)mapView viewForAnnotation:(id )annotation \{

if (annotation == mapView.userLocation) \{

return nil;

MKPinAnnotationView \*pinView = \[\[\[MKPinAnnotationView alloc\]initWithAnnotation:annotation reuseIdentifier:@"Pin"\] autorelease\];

pinView.pinColor = MKPinAnnotationColorRed;

pinView.canShowCallout = YES;

pinView.rightCalloutAccessoryView = \[UIButtonbuttonWithType:UIButtonTypeDetailDisclosure\];

pinView.animatesDrop = YES;

UIButton \*button = \[UIButton buttonWithType:UIButtonTypeDetailDisclosure\];

button.frame = CGRectMake(0, 0, 25, 25);

\[button setTitle:\[NSStringstringWithFormat:@"%f,%f",self.touchCordinate.latitude,self.touchCordinate.longitude\]forState:UIControlStateNormal\];

pinView.rightCalloutAccessoryView = button;

return pinView;

5.iphone开发----计算MKMapView的zoomlevel

计算地图的zoom level，如下：

\#define MERCATOR\_RADIUS 85445659.44705395

\- (int)getZoomLevel:(MKMapView\*)\_mapView \{

return 21-round(log2(\_mapView.region.span.longitudeDelta \* MERCATOR\_RADIUS \* M\_PI / (180.0 \* \_mapView.bounds.size.width)));

我们可以写一个MKMapView的委托方法打印出zoom level

\- (void)mapView:(MKMapView \*)\_mapView regionDidChangeAnimated:(BOOL)animated \{

NSLog(@"zoom level %d", \[self getZoomLevel:\_mapView\]);

结果范围在1-19之间，1就是全球地图。

6.在固定位置画一定大小的圈

UILongPressGestureRecognizer \*lpress = \[\[UILongPressGestureRecognizer alloc\]initWithTarget:self

action:@selector(longPress:)\];

lpress.minimumPressDuration = 0.3;//按0.5秒响应longPress方法

lpress.allowableMovement = 10.0;

//给MKMapView加上长按事件

\[self.\_mapView addGestureRecognizer:lpress\];//mapView是MKMapView的实例

\[lpress release\];

return self;

\- (void)longPress:(UIGestureRecognizer\*)gestureRecognizer \{

if (gestureRecognizer.state == UIGestureRecognizerStateBegan)\{ //这个状态判断很重要

//坐标转换

CGPoint touchPoint = \[gestureRecognizer locationInView:self.\_mapView\];

CLLocationCoordinate2D touchMapCoordinate =

\[self.\_mapView convertPoint:touchPoint toCoordinateFromView:self.\_mapView\];

self.touchCoordinate = touchMapCoordinate;

NSLog(@"location:%f,%f",touchMapCoordinate.latitude,touchMapCoordinate.longitude);

if (nil != self.newAnnotation) \{

\[self.\_mapView removeAnnotation:self.newAnnotation\];

self.newAnnotation = \[Annotation annotationWithCoordinate:self.touchCoordinate\];

self.newAnnotation.title = \[NSStringstringWithFormat:@"%f,%f",self.touchCoordinate.latitude,self.touchCoordinate.longitude\];

if (nil != self.newAnnotation) \{

\[self.\_mapView addAnnotation:self.newAnnotation\];

\[self locationcircle:self.touchCoordinate radius:\[circleScaleText.text doubleValue\]\];

//这里的touchMapCoordinate.latitude和touchMapCoordinate.longitude就是需要的经纬度，

//NSString \*url = \[NSString stringWithFormat:@"http://maps.google.com/maps/api/geocode/json?latlng=%f,%f&sensor=false&region=sh&language=zh-CN", touchMapCoordinate.latitude, touchMapCoordinate.longitude\];

//\[NSThread detachNewThreadSelector:@selector(loadMapDetailByUrl:) toTarget:self withObject:url\];

//在鼠标点击位置添加固定大小的圈

\-(void)locationcircle:(CLLocationCoordinate2D)coordinate radius:(CLLocationDistance)circleradius \{

if (nil != self.locCircle) \{

\[self.\_mapView removeOverlay:locCircle\];

locCircle = \[MKCircle circleWithCenterCoordinate:coordinate radius:circleradius\];

\[self.\_mapView addOverlay:locCircle\];

//改变位置圈的大小

\- (IBAction)changecircleScale\{

\[self dismissWithClickedButtonIndex:0 animated:YES\];

\[self locationcircle:self.touchCoordinate radius:\[circleScaleText.text doubleValue\]\];

\- (MKAnnotationView \*)mapView:(MKMapView \*)mapView viewForAnnotation:(id<MKAnnotation>)annotation \{

if (annotation == mapView.userLocation) \{

return nil;

MKPinAnnotationView \*pinView = \[\[\[MKPinAnnotationView alloc\]initWithAnnotation:annotation reuseIdentifier:@"Pin"\] autorelease\];

pinView.pinColor = MKPinAnnotationColorRed;

pinView.canShowCallout = YES;

pinView.rightCalloutAccessoryView = \[UIButtonbuttonWithType:UIButtonTypeDetailDisclosure\];

pinView.animatesDrop = YES;

UIButton \*button = \[UIButton buttonWithType:UIButtonTypeDetailDisclosure\];

button.frame = CGRectMake(0, 0, 25, 25);

\[button setTitle:\[NSStringstringWithFormat:@"%f,%f",self.touchCoordinate.latitude,self.touchCoordinate.longitude\]forState:UIControlStateNormal\];

pinView.rightCalloutAccessoryView = button;

return pinView;

\- (MKOverlayView \*)mapView:(MKMapView \*)mapView viewForOverlay:(id <MKOverlay>)overlay

if (\[overlay isKindOfClass:\[MKCircle class\]\])

MKCircleView\* circleView = \[\[\[MKCircleView alloc\] initWithOverlay:overlay\]autorelease\];

circleView.fillColor = \[\[UIColor cyanColor\] colorWithAlphaComponent:0.2\];

circleView.strokeColor = \[\[UIColor blueColor\] colorWithAlphaComponent:0.7\];

circleView.lineWidth = 3.0;

return circleView;

return nil;

\- (int)getZoomLevel:(MKMapView\*)mapView \{

return 21-round(log2(mapView.region.span.longitudeDelta \* MERCATOR\_RADIUS \* M\_PI / (180.0 \* mapView.bounds.size.width)));

//一个MKMapView的委托方法控制zoomlevel

\- (void)mapView:(MKMapView \*)mapView regionDidChangeAnimated:(BOOL)animated \{

//NSLog(@"zoom level %d", \[self getZoomLevel:\_mapView\]);

\- (void)setFrame:(CGRect)rect \{

//\[super setFrame:CGRectMake((320-rect.size.width)/2, 130, rect.size.width, 150)\];

//self.center = CGPointMake(320/2, 480/2);

\[super setFrame:CGRectMake(0, 20, 320, 460)\];

\- (void)layoutSubviews \{

CGFloat buttonTop;

for (UIView \*view in self.subviews) \{

if (\[\[\[view class\] description\] isEqualToString:@"UIThreePartButton"\]) \{

view.frame = CGRectMake(view.frame.origin.x,

self.bounds.size.height - view.frame.size.height - 15,

view.frame.size.width,

view.frame.size.height);

buttonTop = view.frame.origin.y+200;

buttonTop -= 40;

NSLog(@"buttontop:%f",buttonTop);

circleLb.frame = CGRectMake(12, 50, 80, 30);

circleScaleText.frame = CGRectMake(100, 52, 150, 25);

changeBtn.frame = CGRectMake(260, 50, 40, 30);

7.mapView 定位当前位置使用CLLocationManager

\#import "UserLoactionTestViewController.h"

@implementation UserLoactionTestViewController

\- (void)loadView \{

\[super loadView\];

mapView = \[\[MKMapView alloc\] initWithFrame:CGRectMake(0, 10, 320, 400)\];

\[mapView setDelegate:self\];

\[mapView setMapType:MKMapTypeStandard\];

\[self.view addSubview:mapView\];

\[mapView release\];

mapView.showsUserLocation=YES;

CLLocationManager \*locationManager = \[\[CLLocationManager alloc\] init\];//创建位置管理器

locationManager.delegate=self;//设置代理

locationManager.desiredAccuracy=kCLLocationAccuracyBest;//指定需要的精度级别

//locationManager.distanceFilter=1000.0f;//设置距离筛选器

\[locationManager startUpdatingLocation\];//启动位置管理器

MKCoordinateSpan theSpan;

//地图的范围 越小越精确

theSpan.latitudeDelta= 0.05f;

theSpan.longitudeDelta=0.05f;

MKCoordinateRegion theRegion;

CLLocationCoordinate2D cr = locationManager.location.coordinate;

theRegion.center = cr; //\[\[locationManager location\] coordinate\];

theRegion.span = theSpan;

\[mapView setRegion:theRegion\];

//NSLog(@"%f %f",mapView.userLocation.location.coordinate.latitude,

// mapView.userLocation.location.coordinate.longitude);

\- (void)locationManager:(CLLocationManager \*)manager didUpdateToLocation:(CLLocation \*)newLocation fromLocation:(CLLocation \*)oldLocation \{

//NSLog(@"dfdfdfd");

mapView.region = MKCoordinateRegionMake(newLocation.coordinate, MKCoordinateSpanMake(0.005f, 0.005f));

\[manager stopUpdatingHeading\];

\- (void)didReceiveMemoryWarning \{

\[super didReceiveMemoryWarning\];

\- (void)viewDidUnload \{

\- (void)dealloc \{

\[super dealloc\];

@end

8.手指控制放大缩小(转的 没自己测验过,以后有需求的时候可以参考下)

CGRect scrollFrame = CGRectMake(20,90,280,280);

UIScrollView \*scrollView = \[\[UIScrollView alloc\] initWithFrame:scrollFrame\];

scrollView.minimumZoomScale = 0.5;

scrollView.maximumZoomScale = 2.0;

scrollView.delegate = self;

UIImage \*bigImage = \[UIImage imageNamed:@"appleLogo.jpg"\];

largeImageView = \[\[UIImageView alloc\] initWithImage:bigImage\];

\[scrollView addSubview:largeImageView\];

scrollView.contentSize = largeImageView.frame.size; //important!

\[self.view addSubview:scrollView\];

\[scrollView release\];

9.长按操作(转) (没尝试过,看到了,先收着)(跟上面地图的长按有点相似)

UILongPressGestureRecognizer \*longpressGesture = \[\[UILongPressGestureRecognizer alloc\] init\];

longpressGesture.minimumPressDuration = 1;

longpressGesture.cancelsTouchesInView = NO;

\[longpressGesture addTarget:self action:@selector(buttonLongPressed:)\];

\[boxButton addGestureRecognizer:longpressGesture\];

\[longpressGesture release\];

11 resizeImage

http://www.iphonedevsdk.com/forum/iphone-sdk-development/7307-resizing-photo-new-uiimage.html

12 在mapview的特定位置上添加图片

CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(latitude, longitude);

MapAnnotation \*annotation = \[\[MapAnnotationalloc\] initWithcoordiante:coordinate\];

\[map\_view addAnnotations: annotation\];

\[annotation release\];

3.写文件的一种方法

NSData \*dataToWrite = \[s dataUsingEncoding: NSUTF8StringEncoding\];

NSFileHandle\* outputFile = \[NSFileHandle fileHandleForWritingAtPath:Log\_FilePath\];

\[outputFile seekToEndOfFile\]; //可以在文件的末尾继续写下去

\[outputFile writeData:dataToWrite\];

实现pushViewController的自定义动画效果

CATransition \*transition = \[CATransition animation\];

transition.duration = 1.0f;  
transition.timingFunction = \[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut\];  
transition.type = @"cube";  
transition.subtype = kCATransitionFromRight;  
transition.delegate = self;  
\[self.navigationController.view.layer addAnimation:transition forKey:nil\];  
  
  
DemoViewController \*demoViewController =  
\[\[DemoViewController alloc\]  
initWithNibName:@"DemoViewController"  
bundle:\[NSBundle mainBundle\]\];  
\[self.navigationController pushViewController: demoViewController animated:YES\];  
  
  
\[demoViewController release\];