Chapter 1 and 2 Welcome

• The first app:hello, iOS!
• Xcode
  • groups & Files
• Interface Builder
  • xib window
  • File's Owner
  • add a object and connect it to source code object
  • view window
  • library window
  • inspector
  • attributes
  • connection
  • size
  • identify
• icon $_Info.plist -> Icon File

Chapter 3 Handling Basic Intraction

Xcode project templates

MVC pattern

IBOutlet

@property (nonatomic, retain) IBOutlet Class * object;

@synthesize object;

IBAction

- (IBAction) functionName:(id)sender;

- (IBAction) funtionName:(id) sender {
}

UIApplicationDelegate

ViewController

Chapter 4 More User Interface Fun

UIImageView

UILabel

UITextField

• Return or Done
  • Return:change the another view
  • Done:back to the current view

• Closing the keyboard

  • UITextField, Did End On Exit
  • UIControl, Touch Down
  • resignFirstResponder

• Value Changed

UISwitch

UISegmentedControl

• Value Changed

UIButton

• Touch Up Inside

comment

• //TODO:

Action Sheet

implement action sheet

UIActionSheet a = [[UIActionSheet alloc] initWithTitle:@"title" delegate:self cancelButtonTitle:@"Cancel" destructiveButtonTitle:@"OK" otherButtontitle:nil];
[a showInView:self.view];
[a release];

UIActionSheetDelegate, didDismissWithButtonIndex

Alert

implement alert

UIAlertView a = [[UIAlertView alloc] initWithTitle:@"t" message:@"m" delegate:nil cancelButtonTitle:@"Cancel" otherButtonTitles:nil];

UIAlertViewDelegate

Chapter 5 rotation and resize

iPhone4(iPhone3, iPhone3 GS) pixel: 320x480

- (BOOL) shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation) interfaceOrientation;
- (BOOL) willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation) interfaceOrientatio duration:(NSTimeInterval) duration;

//UIInterfaceOrientationProtrait
//UIInterfaceOrientationProtraitUpsideDown
//UIInterfaceOrientationLandcapeLeft
//UIInterfaceOrientationLandcapeRight
if (interfaceOrientation == UIInterfaceOrientationPortrait)
{
    button.frame = CGRectMake(0,0,100,100);
}

portrait and landscape views

self.view = self.portrait;

Chapter 6 Multiview

subview size by Interface Builder:Attributes - Simulated User Interface Elements

switch view

[self.oldViewController viewWillDisappear:YES];
[self.newViewController viewWillAppear:YES];
[self.oldViewController.view removeFromSuperView];
[self.view insertSubview:self.newViewController.view atIndex:0];
[self.oldViewController viewDidDisappear:YES];
[self.newViewController viewDidAppear:YES];

view animation

[UIView beginAnimations:@"view flip" context:nil];
[UIView setAnimationDuration:1.25];
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
//UIViewAnimationTransitionFlipFromRight
//UIViewAnimationTransitionFlipFromLeft
//UIViewAnimationTransitionFlipCurlUp
//UIViewAnimationTransitionFlipCurlDown
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.view cache:YES];

Chapter 7 Tab bars and Pickers

Tab bars

• View Controllers
• icon 24x24 pixel
• Tab Bar Item

Picker

Date Picker

//set
NSDate * now = [[NSDate alloc] init];
[datePicker setDate: now animated:NO];
[now release];
//get
NSDate d = [datePicker date];

Picker

- (NSInteger) numberOfComponentsInPickerView:(UIPickerView * )pickerView {
    return column_number;
}
- (NSInteger)pickerView:(UIPickerView * )pickerView numberOfRowsInComponent:(NSInteger) component {
    return row_count;
}
- (NSString * )pickerView:(UIPickerView * )pickerView titleForRow:(NSInteger) row forComponent:(NSInteger) component {
    return row_component_string;
}
- (CGFloat)pickerView:(UIPickerView * )pickerView withForComponent:(NSInteger) component {
    return the_width_of_the_component;
}

Custom Picker

- (UIView * )pickerView:(UIPickerView * )pickerView viewForRow:(NSInteger) row forComponent:(NSInteger)component reusingView:(UIView * ) view {
}

UIPickerView rolls and selects row

[picker selectRow:newValue inComponent:i animated:YES];
[picker reloadComponent:i];

Audio

import AudioToolbox.framework - Reference Type:Relative to Current SDK

NSString * path = [[NSBundle mainBundle]pathForResource:@"crunch" ofType:@"wav"];
SystemSoundID s;
AudioServicesCreateSystemSoundID((CFURLRef)[NSURL fileURLWithPath:path], &s);
AudioServicesPlaySystemSound(s);

delay to perform

[self performSelector:@selector(function-name) withObject:nil afterDelay:.5];

pragma

bundle

NSBundle * b = [NSBudle mainBundle];
NSString * p = [b pathForResource:@"name", ofType:@"suffix"];

Chapter 8 Table Views

Grouped and Plain tables

data source and delegate

- (NSInteger) tableView:(UITableView * )tableView numberOfRowsInSection:(NSInteger)section {
    return count_of_rows_in_section;
}
- (UITableViewCell * )tableView:(UITableView * )tableView cellForRowAtIndexPath:(NSIndexPath * )indexPath {
    static NSString tableId = @"";
    UITableViewCell * c = [tableView dequeueReusableCellWithIdentifier:tableId];
    if (c == nil) {
        //UITableViewCellStyleSubtitle
        //UITableViewCellStyleValue1
        //UITableViewCellStyleValue2
        c = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:tableId] autorelease];
    }
    c.imageView.image = [UIImage imageNamed:@"name.png"];
    c.textLabel.text = [String stringWithFormat:@"%d", [indexPath row]];
    c.detailTextLabel.text = @"detail";
    return c;
}
- (NSInteger) tableView:(UITableView * )table indentationLevelForRowAtIndexPath:(NSIndexPath * )indexPath {
    return indentation_level;
}
- (NSIndexPath * ) tableView:(UITableView * )table willSelectRowAtIndexPath:(NSIndexPath * )indexPath {
    return indexPath;
}
- (void) tableView:(UITableView * )table didSelectRowAtIndexPath:(NSIndexPath * )indexPath {
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
}

- (CGFloat) tableView:(UITableView * )tableView heightForRowAtIndexPath:(NSIndexPath * )indexPath {
    return height;
}

Custom

child view

- (UITableViewCell * )tableView:(UITableView * )tableView cellForRowAtIndexPath:(NSIndexPath * )indexPath {
    static NSString tableId = @"";
    UITableViewCell * c = [tableView dequeueReusableCellWithIdentifier:tableId];
    if (c == nil) {
        c = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:tableId] autorelease];
    }
    CGRect rc = CGRectMake(0, 16, 70, 15);
    UILabel * l = [[UILabel alloc] initWithFrame:rc];
    [c.contentView addSubview:l];
    return c;

inherit UITableViewCell

- (UITableViewCell * )tableView:(UITableView * )tableView cellForRowAtIndexPath:(NSIndexPath * )indexPath {
    static NSString tableId = @"";
    CustomCell * c = (CustomCell * )[tableView dequeueReusableCellWithIdentifier:tableId];
    if (c == nil) {
        NSArray * nib = [[NBundle mainBundle] loadNibNamed:@"CustomCell" owner self options:nil];
        for (id obj in nib) {
            if ([obj isKindOfClass:[CustomCell class]]) {
                c = (CustomCell * )obj;
            }
        }
    }
    return c;
}

Section

- (NSInteger) numberOfSectionsInTableView:(UITableView * )tableView {
    return count_of_section;
}
- (NSString * )tableView:(UITableView * )table titleForHeaderInSection:(NSInteger)section {
    return [NSString stringWithFormat(@"%@", section)];
}

Indexed

- (NSArray * )sectionIndexTitlesForTableView:(UITableView * )tableView {
    return ;
}

search

• earch bar
  • searchBarTextDidBeginEditing:
  • searchBar:textDidChange
  • searchBarCancelButtonClicked

Chapter 9 Navigation Controllers and Table Views

Navigation

1. add nav(UINavigationController) in window(NSWindow)

[window addSubview:nav];

2. set firstView(UITableViewController) as nav rootViewController

Root View Controller identify is firstCtrller

3. title

firstCtrller.title = @"title"

4. navigate a view

[nav pushViewController:subController animated:YES];

5. back to view

[nav popViewControllerAnimated:YES];

Table view

accessory

//UITableVieCellAccessoryDisclosureIndicator
//UITableVieCellAccessoryDisclosureButton
//UITableViewCellAccessoryCheckmark
//UITableViewCellAccessoryNone
accessoryType = UITableViewCellAccessoryDisclosureIndicator;

- (void) tableView:(UITableView * )tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath * )indexPath {
}

UIButton * btn = [UIButton buttonWIthType:UIButtonTypeCustom];
btn addTarget:self action:@selector(function_name:) forControlEvents:UIControlEventTouchUpInside];
cell.accessoryView = btn;

edit mode

[self.tableView setEditing:!self.tableView.editing animated:YES];

UIBarButtonItem * b = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStyleBordered target:self action:@selector(fun)];
self.navigationItem.rightBarButton Item = b
[b release];

- (UITableViewCell * )tableView:(UITableView * )tableView cellForRowAtIndexPath:(NSIndexPath * )indexPath {
    cell.showsRecorderControl = YES;
}

- (UITableViewCellEditingStyle)tableView:(UITableView * )tableView editingStyleForRowAtIndexPath:(NSIndexPath * )indexPath {
    return UITableViewCellEditingStyleNone;
}
- (BOOL)tableView:(UITableView * )tableView canMoveRowAtIndexPath:(NSIndexPath * )indexPath {
    return YES;
}
- (void)tableView:(UITableView * )tableView moveRowAtIndexPath:(NSIndexPath * )fromIndexPath toIndexPath:(NSIndexPath * )toIndexPath {
}
- (void)tableView:(UITableView * )tableView commitEditingStyle:(UITableViewCellEditingStyle) editingStyle forRowAtIndexPath:(NSIndexPath * )indexPath {
    [tableView deleteRowsAtInexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}

[self.tableView reloadData];

Chapter 10 Setting and Defaults

Setting

Resource - Settings Bundle: Settings.bundle - Root.plist

Root Dictionary
    PreferenceSpecifiers Array
        Item 1 Dictionary
            Type PSGroupSpecifier
            Tile General Info
        Item 2 Dictionary
            Type String PSTextFieldSpecifier
            Title String Username
            Key String username
            AutocapitalizationType String None
            AutocorrectionType String No
        Item 3 Dictionary
            Type String PSTextFieldSpecifier
            Title String Password
            Key String password
            AutocapitalizationType String None
            AutocorrectionType String No
            IsSecure Boolean Yes 
        Item 4 Dictionary
            Type String PSMultiValueSpecifier
            Title String Protocol
            Key String protocol
            DefaultValue String SMTP
            Titles Array
                Item 1 String HTTP
                Item 2 String SMTP
                Item 3 String NNTP
                Item 4 String IMAP
                Item 5 String POP3
            Values Array
                Item 1 String HTTP
                Item 2 String SMTP
                Item 3 String NNTP
                Item 4 String IMAP
                Item 5 String POP3
        Item 5 Dictionary
            Type String PSToggleSwitchpecifier
            Title String WarpDriver
            Key String warp
            TrueValue String Engaged
            FalseValue String Disabled
            DefaultValue String Engaged
        Item 6 Dictionary
            Type PSGroupSpecifier
            Tile Warp Factor
        Item 7 Dictionary
                Type String PSSliderSpecifier
                Key String warpfactor
                DefaultValue String 5
                MinimumValue String 1
                MaximumValue String 10
                MinimumValueImage String min.png
                MaximumValueImage String max.png
        Item 8 Dictionary
            Type PSGroupSpecifier
            Tile Additional Info
        Item 9 Dictionary
            Type String PSSchildPaneSpecifier
            Tile String More Settings
            File String More

Defaults

NSUserDefaults d = [NSUserDefaults standardUserDefaults];
[d setObject:@"value" forKey:@"key"];
[d objectForKey:@"key"];

Chapter 11 Data Persistence

File

usr
    tmp
    Root
    Media
    Libary
        Preferences -- NSUserDefaults
    Applications
        Documents
        Library
        tmp

Applications/Documents

NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDoumentDirectory, NSUserDomainMask, YES);
NSString * directory = paths[0]
NSString * file = [directory stringByAppendingPathComponent:@"filename"];

Applications/tmp

NSString * tmp = NSTemporaryDirectory();
NSString * f = [tmp stringByAppendingComponent:@"filename"];

Property List

Array Dictionary Data String Number Date

//write
[obj writeToFile:@"path":atomically:YES];
//read
if ([NSFileManager defaultManager] fileExistsAtPath:filePath]) {
    obj = [[class alloc]initWithContentFile:filePath];
}

Archives

protocol

- (void) encodeWithCoder:(NSCoder * )encoder {
    [super encodeWithCoder:encode];
    [encode encodeObject: self.obj forKey: @"key"];
}

- (id) initWithCode: (NSCoder * )decoder {
    if (self = [super init]) {
        self.obj = [decoder decodeObjectForKey:@"key"];
    }
    return self;
}
- (id) copyWithZone:(NSZone * ) zone {
    Class * copy = [[self class] allocWithZone:zone] init];
    copy.obj = [[self.obj copyWithZone:zone] autorelease];
    return copy;
}

write

NSMutableData * data = [[NSMutableData alloc] init];
NSKeyedArchiver * archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[archiver encodeObject:obj forKey:@"root"];
[archiver finishEncoding];
[data finishEncoding];
[data writeToFile: [self dataFilePath] atomically:YES];
[obj release];
[archiver release];
[data release];

read

NSData * data = [[NSMutableData alloc] initWithContentsOfFile: [self path]];
NSKeyedUnarchiver * unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData: data];
Class * obj = [unarchiver decodeObjectForKey:@"root"];
[unarchiver finishDecoding];
//do something ...
[unarchiver release];
[data release];

SQLite3

sqlite3 * db;
sqlite3_open([path UTF8String]);
char* err;
sqlite3_exec(db, sql, NUL, NULL, &err);
sqlite3_stmt * statement;
char * sql = "select id, value from tb";
sqlite3_prepare_v2(db, sql, -1, &statement, 0);
while (sqlite3_step(statement) == SQLITE_ROM) {
    int id = sqlite3_column_int(statement, 0);
    char* d = (char*)sqlite3_column_text(statement, 1);
    NSString value = [[NSString alloc] initWithUTF8String:d];
    //do something...
    [value release];
}

char * sql = "insert into tb values (?, ?);";
sqlite3_stmt * stmt;
if (sqlite3_prepare_v2(database, sql, -1, &stmt, nil) == SQLITE_OK) {
    sqlite3_bind_int(stmt, 1, 235);
    sqlite3_bind_text(stmt, 2, "value", -1, NULL);
}
if (sqlite3_step(stmt) != SQLITE_DONE) {
    //error to do something ...
}
sqlite3_finalize(stmt);
sqlite3_close(db);

Core Data

use core data storage

CoreData.xcdatamodel

Entity

Managed Object

Attribute

Relationship

Fetched property

persistent store (backing store)

• SQLite3, XML, memory store can be implemented for backing store
• backing store is created and configured in BIDAppDelegate

NSManagedObjectContext ctx = [[[UIApplication sharedApplication] delegate] managedObjectContext];

Create

NSManagedObject * t = [NSEntityDescription insertNewObjectForEntityForName:@"s" inManagedObjectContext:ctx];

Retrieve

NSFetchRequest * r = [[NSFetchRequest alloc] init];
NSEntityDescription * ed= [NSEntityDescription entityForName:@"s" inManagedObjectContext:ctx];
[r setEntity:ed];
[ctx save:&e];

NSPredicate * pred = [NSPredicate predicateWithFormat:@"(s = %@)", s];
[r setPredicate: pred];
NSError * e;
NSArray * objs = [ctx executeFetchRequest:r error: &e];
if (objs == nil) {
    //error...
}

observer pattern

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillTerminate:) name:UIApplicationWillTerminateNotification object:app];

Chapter 12 Quartz and OpenGL

Quartz 2D

The Quartz 2D API is part of the Core Graphics framework, so you may see Quartz referred to as Core Graphics or, simply, CG.

coordinate

CGPoint CGSize CGRect

struct CGPoint {
    float x;
    float y;
};
struct CGSize {
    float width;
    float height;
};
struct CGRect {
    CGPoint origin;
    CGSize size;
};

UIColor

Mode:RGBA HSV HSL CMYK

Create and CGColor

UIColor c = [UIColor colorWithRed:1.0f green:0.0f blue:0.0f alpha:1.0f];
c.CGColor;

Draw

[self setNeedsDisplay];
- (void)drawRect:(CGRect)rect {
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(ctx, 2.0);
CGContextSetStrokeColorWithColor(ctx, clr.CGColor);
//draw line
CGContextMoveToPoint(ctx, p1.x, p1.y);
CGContextAddLineToPoint(ctx, p2.x, p2.x);
CGContextStrokePath(ctx);

CGContextSetFillColorWithColor(ctx, clr.CGColor);
CGRect rc = CGRectMake(x, y, w, h);

//draw rect
CGContextAddRect(ctx, rc);
CGContextDrawPath(ctx, kCGPathFillStroke);
//draw ellipse
CGContextAddEllipseInRect(ctx, rc);
CGContextDrawPath(ctx, kCGPathFillStroke);
//draw image
[[UIImage imagedNamed:@"image.png"]drawAtPoint:p];
}

Optimizing

CGRect dirty_rc = CRectUnion(old_rc, current_rc)
[self setNeedsDisplayInRect:dirty_rc];

OpenGL ES

OpenGL ES = OpenGL Embeded System

OpenGL 3D coordinate to View 2D coordinate

Texture2D creates opengl 2d textures from images or text

draw

//reset virtual world
glLoadIdentity();
//clean background
glClearColor(r, g, b, a);
glClear(GL_COLOR_BUFFER_BIT);
//set color
CGFloat c = CGColorGetComponents((CGColorRef)color.GCColor);
CGFloat * r = c[0];
CGFloat * g = c[1];
CGFloat * b = c[2];
glColor4f(r, g, b, 1.0);
//disable texture
gDisable(GL_TEXTURE_2D);
//convert to vertex point and draw vertex points
GLfloat vec[4];
vec[0] = p1.x;
vec[1] = self.frame.size.height - p1.y;
vec[2] = p2.x;
vec[3] = self.frame.size.height - p2.y;
gLineWidth(2.0);
glVertexPointer(2, GL_FLOAT, 0, vec);
glDrawArray(GL_LINES, 0, 2);
//render
glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);
[context presentRenderbuffer:GL_RENDERBUFFER_OES];

//draw image
s = [[Texture2D alloc] initWithImage:[UIImage imaged:@"picture.png"]];
glBindTexture(GL_TEXTURE_2D, s.name);
glEnable(GL_TEXTURE_2D);
[s drawAtPoint:CGPointMake(x, self.fram.size.height - y)];

Chapter 13 Taps, Touches and Gestures

responder chain

touches:the starting phase of the event

event:representing the event.

- (void) touchesBegan:(NSSet * )touches withEvent:(UIEvent * ) event {

    [event touchesForView:self.view];
    UITouch t = [touches andObject];
    [t tapCount];
    CGPoint p = [t locationInView:self];
}
- (void) touchesCancelled:(NSSet * )touches withEvent:(UIEvent * ) event {
}
- (void) touchesEnded:(NSSet * )touches withEvent:(UIEvent * ) event {
}
- (void) touchesMoved:(NSSet * )touches withEvent:(UIEvent * ) event {
}

Chapter 14 Core Location

three technologies: * GPS * cell ID location * Wi-Fi

start

self.lmgr = [[CLLocationManger alloc] init];
locationManager.delegate = self;
//kCLLocationAccuracyNearestTenMeters
//kCLLocationAccuracyNearestHundredMeters
//kCLLocationAccuracyNearestKilometers
//kCLLocationAccuracyNearestThreeKilometers
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
//float
locationManager.distanceFilter = kCLDistanceFilterNone;
[locationMnager startUpdatingLocation];

CLLocation

CLLocationDegrees latitude = l.coordinate.latitude;
CLLocationDegrees longitude = l.coordinate.longitude;
CLLocationDistance altitude = l.altitude;
CLLocationAccuracy hAccuracy = l.horizontalAccuracy
CLLocationAccuracy vAccuracy = l.verticalAccuracy
CLLocationDistance distance = [from getDistanceFrom:to];
CLLocationDistance distance = [from getDistanceFrom:to];

delegate

@interface where:UIViewController  {
    CLLocationManager * lmgr;
}
@end

@implementation where
- (void) locationManager:(CLLocationManager * )manager didUpdateToLocation:(CLLocation * )newLocation fromLocation:(CLLocation * ) oldLocation {

}
- (void) locationManager:(CLLocationManager * )manager didFailWithError:(NSError * )error {
    error.code;
}
@end

Chapter 15 Accelerometer

Hide status Bar

Info.plist UIStatusBarHidden Boolean

Accelerometer

• portrait:y = -1.0
• upside down:y = 1.0
• landscape left:x = 1.0
• landscape right:x= -1.0
• laying with back:z = -1.0
• laying with front:z = 1.0

UIAccelerometer * a = [UIAccelermeter sharedAccelerometer];
a.delegate = self;
a.updateInterval = 1.0f/6.0f;

@interface VCer:UIViewController  {
}

- (void) accelerometer:(UIAccelerometer * ) accelerometer 
didAccelerate:(UIAcceleration * ) acceleration {
    //acceleration.x;
    //acceleration.y;
    //acceleration.z;

}
if ([UIIMagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypePhotoLibrary]) {
    UIImagePickerController * picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;
    //UIImagePickerControllerSourceTypeCamera
    //UIImagePickerControllerSourceTypeSavedPhotosAlbum
    picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    [self presentModalViewController:picker animated:YES];
    [picker release];
}


@interface VCer:NSObject 
< UIIMagePickerControllerDelegate, UINavigationControllerDelegate > {
}


- (void)imagePickerController:(UIImagePickerController * )picker
didFinishPickingImage:(UIImage * )image
editingInfo:(NSDictionary * )editingInfo {
    UIImage * selectedImage = image;
    UIImage * originalImage = [editingInfo objectForKey: UIImagePickerControllerOriginalImage];
    //
    NSValue * cropRect = [editingInfo objectForKey:UIIMagePickerControllerCropRect];
    CGRect theRect = [cropRect CGRectValue];
    //TODO:
    [picker dismissModalViewControllerAnimated:YES];
}
- (void)imagePickerControllerDidCancel {
    [picker dismissModalViewControllerAnimated:YES];
}


Chapter 17 Localization

Localiztion project (.lproj)

The Localized String Macro(NSLocalizedString)

NSLocale * locale = [NSLocale currentLocale];
NSString * displayNameString = [locale displayNameForKey:NSLocaleIdentifier value:[locale localeIdentifier]];


Localizing xib

generating and localizing a string file

genstring paths/all m files


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日期: 2015-09-28 17:30:06, 9 years and 110 days ago

• syntax files loading procedurce
  • 1 $VIM/vimfiles/syntax/type.vim (~/.vim/syntax/type.vim)
  • 2 $VIMRUNTIME/syntax/type.vim
  • 3 $VIM/vimfiles/after/syntax/type.vim (~/.vim/after/syntax/type.vim)

create markdown.vim in after/syntax

• priority When several syntax items may match, these rules are used:
  • 1 When multiple Match or Region items start in the same position, the item defined last has priority.
  • 2 A Keyword has priority over Match and Region items.
  • 3 An item that starts in an earlier position has priority over items that start in later positions.

syn region markdownItalic start="\S\@<=\*\|\*\S\@=" end="" keepend contains=markdownLineStart
syn region markdownItalic start="\S\@<=_\|_\S\@=" end="" keepend contains=markdownLineStart

in markdown.vim, add two lines above.