iphone - open - uiwebview tutorial

Mostrar UIImage local en UIWebview

Question

Mi configuración:
Tengo una vista web en mi aplicación para iPhone, yendo a www.misitio.com.

Pruebas
Si configuro "backgroundcolor uicolor clearcolor" en mi vista web y dibujo un uiimage detrás de mi vista web, ¡no se desplazará con mi vista web!

Mi problema:
Me gustaría la imagen con la vista web. Además, esta imagen debe almacenarse en la aplicación iPhone y no en el servidor web (por supuesto, si pongo la imagen en el servidor web, simplemente puedo dibujarla como fondo con CSS).

¿Cuál es la mejor manera de acceder a esta imagen a través de html / javascript / Objective C, para que pueda ver esta imagen local como fondo de mi sitio web? ¿Hay alguna manera?

Answer 1

Simplemente podría agregar esta línea

webView.backgroundColor=[UIColor colorWithPatternImage:[UIImage imageNamed:@"light.jpg"]];

Answer 2

Tienes unas cuantas opciones. Puede cargar la página con una baseURL de

[[NSBundle mainBundle] bundleURL]

o puede usar javascript para establecer la ruta a su imagen usando el siguiente método.

[[NSBundle mainBundle] URLForResource:@"myimage" withExtension:@"png"]

Editar: Marque aquí Enlace a recursos dentro de WebView - iPhone . Parece que usará pathForResource en lugar de URLForResource.

Edición 2: es posible que desee utilizar los URI de datos para agregar sus propios archivos locales al sitio web.

YourCode.m

#import "NSString+DataURI.h"
#import "NSData+Base64.h"
...

-(void)webViewDidFinishLoad:(UIWebView *)webView
{
    NSString *imgPath = [[NSBundle mainBundle] pathForResource:@"image" ofType:@"png"];
    NSData *imgData = [NSData dataWithContentsOfFile:imgPath];
    NSString *imgB64 = [[imgData base64Encoding] pngDataURIWithContent];

    NSString *javascript = [NSString stringWithFormat:@"document.body.style.backgroundImage=''url(%@)'';", imgB64];
    [webView stringByEvaluatingJavaScriptFromString:javascript];
}

El siguiente código NO HICE ESCRIBIR y no estoy seguro del origen

NSData + Base64.h

@interface NSData (Base64) 

+ (NSData *)dataWithBase64EncodedString:(NSString *)string;
- (id)initWithBase64EncodedString:(NSString *)string;

- (NSString *)base64Encoding;
- (NSString *)base64EncodingWithLineLength:(unsigned int) lineLength;

@end

NSData.Base64.m

#import "NSData+Base64.h"

static char encodingTable[64] = {
''A'',''B'',''C'',''D'',''E'',''F'',''G'',''H'',''I'',''J'',''K'',''L'',''M'',''N'',''O'',''P'',
''Q'',''R'',''S'',''T'',''U'',''V'',''W'',''X'',''Y'',''Z'',''a'',''b'',''c'',''d'',''e'',''f'',
''g'',''h'',''i'',''j'',''k'',''l'',''m'',''n'',''o'',''p'',''q'',''r'',''s'',''t'',''u'',''v'',
''w'',''x'',''y'',''z'',''0'',''1'',''2'',''3'',''4'',''5'',''6'',''7'',''8'',''9'',''+'',''/'' };

@implementation NSData (VQBase64)

- (id)initWithString:(NSString *)string {
    if ((self = [super init])) {
        [self initWithBase64EncodedString:string];
    }
    return self;

}


+ (NSData *) dataWithBase64EncodedString:(NSString *) string {
    return [[[NSData allocWithZone:nil] initWithBase64EncodedString:string] autorelease];
}

- (id) initWithBase64EncodedString:(NSString *) string {
    NSMutableData *mutableData = nil;

    if( string ) {
        unsigned long ixtext = 0;
        unsigned long lentext = 0;
        unsigned char ch = 0;
        unsigned char inbuf[4], outbuf[3];
        short i = 0, ixinbuf = 0;
        BOOL flignore = NO;
        BOOL flendtext = NO;
        NSData *base64Data = nil;
        const unsigned char *base64Bytes = nil;

        // Convert the string to ASCII data.
        base64Data = [string dataUsingEncoding:NSASCIIStringEncoding];
        base64Bytes = [base64Data bytes];
        mutableData = [NSMutableData dataWithCapacity:[base64Data length]];
        lentext = [base64Data length];

        while( YES ) {
            if( ixtext >= lentext ) break;
            ch = base64Bytes[ixtext++];
            flignore = NO;

            if( ( ch >= ''A'' ) && ( ch <= ''Z'' ) ) ch = ch - ''A'';
            else if( ( ch >= ''a'' ) && ( ch <= ''z'' ) ) ch = ch - ''a'' + 26;
            else if( ( ch >= ''0'' ) && ( ch <= ''9'' ) ) ch = ch - ''0'' + 52;
            else if( ch == ''+'' ) ch = 62;
            else if( ch == ''='' ) flendtext = YES;
            else if( ch == ''/'' ) ch = 63;
            else flignore = YES;

            if( ! flignore ) {
                short ctcharsinbuf = 3;
                BOOL flbreak = NO;

                if( flendtext ) {
                    if( ! ixinbuf ) break;
                    if( ( ixinbuf == 1 ) || ( ixinbuf == 2 ) ) ctcharsinbuf = 1;
                    else ctcharsinbuf = 2;
                    ixinbuf = 3;
                    flbreak = YES;
                }

                inbuf [ixinbuf++] = ch;

                if( ixinbuf == 4 ) {
                    ixinbuf = 0;
                    outbuf [0] = ( inbuf[0] << 2 ) | ( ( inbuf[1] & 0x30) >> 4 );
                    outbuf [1] = ( ( inbuf[1] & 0x0F ) << 4 ) | ( ( inbuf[2] & 0x3C ) >> 2 );
                    outbuf [2] = ( ( inbuf[2] & 0x03 ) << 6 ) | ( inbuf[3] & 0x3F );

                    for( i = 0; i < ctcharsinbuf; i++ )
                        [mutableData appendBytes:&outbuf[i] length:1];
                }

                if( flbreak )  break;
            }
        }
    }

    self = [self initWithData:mutableData];
    return self;
}

#pragma mark -

- (NSString *) base64Encoding {
    return [self base64EncodingWithLineLength:0];
}

- (NSString *) base64EncodingWithLineLength:(unsigned int) lineLength {
    const unsigned char     *bytes = [self bytes];
    NSMutableString *result = [NSMutableString stringWithCapacity:[self length]];
    unsigned long ixtext = 0;
    unsigned long lentext = [self length];
    long ctremaining = 0;
    unsigned char inbuf[3], outbuf[4];
    unsigned short i = 0;
    unsigned short charsonline = 0, ctcopy = 0;
    unsigned long ix = 0;

    while( YES ) {
        ctremaining = lentext - ixtext;
        if( ctremaining <= 0 ) break;

        for( i = 0; i < 3; i++ ) {
            ix = ixtext + i;
            if( ix < lentext ) inbuf[i] = bytes[ix];
            else inbuf [i] = 0;
        }

        outbuf [0] = (inbuf [0] & 0xFC) >> 2;
        outbuf [1] = ((inbuf [0] & 0x03) << 4) | ((inbuf [1] & 0xF0) >> 4);
        outbuf [2] = ((inbuf [1] & 0x0F) << 2) | ((inbuf [2] & 0xC0) >> 6);
        outbuf [3] = inbuf [2] & 0x3F;
        ctcopy = 4;

        switch( ctremaining ) {
            case 1:
                ctcopy = 2;
                break;
            case 2:
                ctcopy = 3;
                break;
        }

        for( i = 0; i < ctcopy; i++ )
            [result appendFormat:@"%c", encodingTable[outbuf[i]]];

        for( i = ctcopy; i < 4; i++ )
            [result appendString:@"="];

        ixtext += 3;
        charsonline += 4;

        if( lineLength > 0 ) {
            if( charsonline >= lineLength ) {
                charsonline = 0;
                [result appendString:@"/n"];
            }
        }
    }

    return [NSString stringWithString:result];
}

@end

NSString + DataURI.h

#import <Foundation/Foundation.h>

@interface NSString(DataURI)
- (NSString *) pngDataURIWithContent;
- (NSString *) jpgDataURIWithContent;
@end

NSString + DataURI.m

#import "NSString+DataURI.h"


@implementation NSString(DataURI)

- (NSString *) pngDataURIWithContent;
{
    NSString * result = [NSString stringWithFormat: @"data:image/png;base64,%@", self];
    return result;
}

- (NSString *) jpgDataURIWithContent;
{
    NSString * result = [NSString stringWithFormat: @"data:image/jpg;base64,%@", self];
    return result;
}

@end