flutter与原生混合开发中,关于资源图片的存储 ####情况一:flutter于原生各存一份 优点:使用方便,flutter 与 原生 各自负责自己的加载; 缺点:占用体积大, APP包 和 运行时内存 都会存在2份图片资源
####情况二:只原生存一份,使用二进制文件传输给flutter 优点:APP包里面只有1份资源图片 缺点:运行时内容还是会有2份资源图片的 占用;
####情况三:只原生存一份,使用"外接纹理"传输给flutter 优点1:APP包里面只有1份资源图片, 内存中也只存在1份资源; 优点2:原生平台通过外接纹理共享内存给flutter; 缺点:目前这方面的文档还很少,用的人还不多;可能会踩坑
###简单介绍一下外接纹理的东西 长话短说: 1.就是iOS端把图片UIImage写进一块特定的"内存区域", 2.flutter端可以直接从那块"内存区域"读取, 3.然后绘画(或者叫渲染)到手机屏幕上
###此处应该有一张思维导图 (目前还没画, 后面有机会再补一张吧;) 直入正题,看代码 https://github.com/xhw0525/daex_texture ###dart代码:(关键代码)
BPage.dart
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
class BPage extends StatefulWidget {
BPage({Key key}) : super(key: key);
@override
_BPageState createState() => _BPageState();
}
class _BPageState extends State<BPage> {
MethodChannel _channel = MethodChannel('duia_texture_channel');//名称随意, 2端统一就好
int daTextureId = -1; //系统返回的正常id会大于等于0, -1则可以认为 还未加载纹理
@override
void initState() {
super.initState();
newTexture();
}
@override
void dispose() {
super.dispose();
if (daTextureId>=0){
_channel.invokeMethod('dispose', {'textureId': daTextureId});
}
}
void newTexture() async {
daTextureId = await _channel.invokeMethod('create', {
'img':'123.gif',//本地图片名
'width': 200,
'height': 300,
'asGif':true,//是否是gif,也可以不这样处理, 平台端也可以自动判断
});
setState(() {
});
}
Widget getTextureBody(BuildContext context) {
return Container(
// color: Colors.red,
width: 300,
height: 300,
child: Texture(
textureId: daTextureId,
),
);
}
@override
Widget build(BuildContext context) {
Widget body = daTextureId>=0 ? getTextureBody(context) : Text('loading...');
return Scaffold(
appBar: AppBar(
title: Text("daex_texture"),
),
body: Container(
height: 500,
width: 500,
child: body,
),
);
}
}
###iOS(关键代码) DuiaflutterextexturePlugin.m
//
// DuiaflutterextexturePresenter.m
// Pods
//
// Created by xhw on 2020/5/15.
//
#import "DuiaflutterextexturePresenter.h"
#import <Foundation/Foundation.h>
//#import <OpenGLES/EAGL.h>
//#import <OpenGLES/ES2/gl.h>
//#import <OpenGLES/ES2/glext.h>
//#import <CoreVideo/CVPixelBuffer.h>
#import <UIKit/UIKit.h>
#import <SDWebImage/SDWebImageDownloader.h>
#import <SDWebImage/SDWebImageManager.h>
static uint32_t bitmapInfoWithPixelFormatType(OSType inputPixelFormat, bool hasAlpha){
if (inputPixelFormat == kCVPixelFormatType_32BGRA) {
uint32_t bitmapInfo = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host;
if (!hasAlpha) {
bitmapInfo = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Host;
}
return bitmapInfo;
}else if (inputPixelFormat == kCVPixelFormatType_32ARGB) {
uint32_t bitmapInfo = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Big;
return bitmapInfo;
}else{
NSLog(@"不支持此格式");
return 0;
}
}
// alpha的判断
BOOL CGImageRefContainsAlpha(CGImageRef imageRef) {
if (!imageRef) {
return NO;
}
CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef);
BOOL hasAlpha = !(alphaInfo == kCGImageAlphaNone ||
alphaInfo == kCGImageAlphaNoneSkipFirst ||
alphaInfo == kCGImageAlphaNoneSkipLast);
return hasAlpha;
}
@interface DuiaflutterextexturePresenter()
@property (nonatomic) CVPixelBufferRef target;
@property (nonatomic,assign) CGSize size;
@property (nonatomic,assign) CGSize imageSize;//图片实际大小 px
@property(nonatomic,assign)Boolean useExSize;//是否使用外部设置的大小
@property(nonatomic,assign)Boolean iscopy;
//gif
@property (nonatomic, assign) Boolean asGif;//是否是gif
//下方是展示gif图相关的
@property (nonatomic, strong) CADisplayLink * displayLink;
@property (nonatomic, strong) NSMutableArray<NSDictionary*> *images;
@property (nonatomic, assign) int now_index;//当前展示的第几帧
@property (nonatomic, assign) CGFloat can_show_duration;//下一帧要展示的时间差
@end
@implementation DuiaflutterextexturePresenter
- (instancetype)initWithImageStr:(NSString*)imageStr size:(CGSize)size asGif:(Boolean)asGif {
self = [super init];
if (self){
self.size = size;
self.asGif = asGif;
self.useExSize = YES;//默认使用外部传入的大小
if ([imageStr hasPrefix:@"http://"]||[imageStr hasPrefix:@"https://"]) {
[self loadImageWithStrFromWeb:imageStr];
} else {
[self loadImageWithStrForLocal:imageStr];
}
}
return self;
}
-(void)dealloc{
}
- (CVPixelBufferRef)copyPixelBuffer {
//copyPixelBuffer方法执行后 释放纹理id的时候会自动释放_target
//如果没有走copyPixelBuffer方法时 则需要手动释放_target
_iscopy = YES;
// CVPixelBufferRetain(_target);//运行发现 这里不用加;
return _target;
}
-(void)dispose{
self.displayLink.paused = YES;
[self.displayLink invalidate];
self.displayLink = nil;
if (!_iscopy) {
CVPixelBufferRelease(_target);
}
}
// 此方法能还原真实的图片
- (CVPixelBufferRef)CVPixelBufferRefFromUiImage:(UIImage *)img size:(CGSize)size {
if (!img) {
return nil;
}
CGImageRef image = [img CGImage];
// CGSize size = CGSizeMake(5000, 5000);
// CGFloat frameWidth = CGImageGetWidth(image);
// CGFloat frameHeight = CGImageGetHeight(image);
CGFloat frameWidth = size.width;
CGFloat frameHeight = size.height;
//兼容外部 不传大小
if (frameWidth<=0 || frameHeight<=0) {
if (img!=nil) {
frameWidth = CGImageGetWidth(image);
frameHeight = CGImageGetHeight(image);
}else{
frameWidth = 1;
frameHeight = 1;
}
}else if (!self.useExSize && img!=nil) {//使用图片大小
frameWidth = CGImageGetWidth(image);
frameHeight = CGImageGetHeight(image);
}
BOOL hasAlpha = CGImageRefContainsAlpha(image);
CFDictionaryRef empty = CFDictionaryCreate(kCFAllocatorDefault, NULL, NULL, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
[NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
empty, kCVPixelBufferIOSurfacePropertiesKey,
nil];
// NSDictionary *options = @{
// (NSString *)kCVPixelBufferCGImageCompatibilityKey:@YES,
// (NSString *)kCVPixelBufferCGBitmapContextCompatibilityKey:@YES,
// (NSString *)kCVPixelBufferIOSurfacePropertiesKey:[NSDictionary dictionary]
// };
CVPixelBufferRef pxbuffer = NULL;
CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, frameWidth, frameHeight, kCVPixelFormatType_32BGRA, (__bridge CFDictionaryRef) options, &pxbuffer);
NSParameterAssert(status == kCVReturnSuccess && pxbuffer != NULL);
CVPixelBufferLockBaseAddress(pxbuffer, 0);
void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
NSParameterAssert(pxdata != NULL);
CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
uint32_t bitmapInfo = bitmapInfoWithPixelFormatType(kCVPixelFormatType_32BGRA, (bool)hasAlpha);
CGContextRef context = CGBitmapContextCreate(pxdata, frameWidth, frameHeight, 8, CVPixelBufferGetBytesPerRow(pxbuffer), rgbColorSpace, bitmapInfo);
// CGContextRef context = CGBitmapContextCreate(pxdata, size.width, size.height, 8, CVPixelBufferGetBytesPerRow(pxbuffer), rgbColorSpace, (CGBitmapInfo)kCGImageAlphaNoneSkipFirst);
NSParameterAssert(context);
CGContextConcatCTM(context, CGAffineTransformIdentity);
CGContextDrawImage(context, CGRectMake(0, 0, frameWidth, frameHeight), image);
CGColorSpaceRelease(rgbColorSpace);
CGContextRelease(context);
CVPixelBufferUnlockBaseAddress(pxbuffer, 0);
return pxbuffer;
}
#pragma mark - image
-(void)loadImageWithStrForLocal:(NSString*)imageStr{
if (self.asGif) {
self.images = [NSMutableArray array];
[self sd_GIFImagesWithLocalNamed:imageStr];
} else {
UIImage *iamge = [UIImage imageNamed:imageStr];
self.target = [self CVPixelBufferRefFromUiImage:iamge size:self.size];
}
}
-(void)loadImageWithStrFromWeb:(NSString*)imageStr{
__weak typeof(DuiaflutterextexturePresenter*) weakSelf = self;
[[SDWebImageDownloader sharedDownloader] downloadImageWithURL:[NSURL URLWithString:imageStr] completed:^(UIImage * _Nullable image, NSData * _Nullable data, NSError * _Nullable error, BOOL finished) {
if (weakSelf.asGif) {
for (UIImage * uiImage in image.images) {
NSDictionary *dic = @{
@"duration":@(image.duration*1.0/image.images.count),
@"image":uiImage
};
[weakSelf.images addObject:dic];
}
[weakSelf startGifDisplay];
} else {
weakSelf.target = [weakSelf CVPixelBufferRefFromUiImage:image size:weakSelf.size];
if (weakSelf.updateBlock) {
weakSelf.updateBlock();
}
}
}];
}
-(void)updategif:(CADisplayLink*)displayLink{
// NSLog(@"123--->%f",displayLink.duration);
if (self.images.count==0) {
self.displayLink.paused = YES;
[self.displayLink invalidate];
self.displayLink = nil;
return;
}
self.can_show_duration -=displayLink.duration;
if (self.can_show_duration<=0) {
NSDictionary*dic = [self.images objectAtIndex:self.now_index];
if (_target &&!_iscopy) {
CVPixelBufferRelease(_target);
}
self.target = [self CVPixelBufferRefFromUiImage:[dic objectForKey:@"image"] size:self.size];
_iscopy = NO;
self.updateBlock();
self.now_index += 1;
if (self.now_index>=self.images.count) {
self.now_index = 0;
// self.displayLink.paused = YES;
// [self.displayLink invalidate];
// self.displayLink = nil;
}
self.can_show_duration = ((NSNumber*)[dic objectForKey:@"duration"]).floatValue;
}
}
- (void)startGifDisplay {
self.displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(updategif:)];
// self.displayLink.paused = YES;
[self.displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
}
- (void)sd_GifImagesWithLocalData:(NSData *)data {
if (!data) {
return;
}
CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
size_t count = CGImageSourceGetCount(source);
UIImage *animatedImage;
if (count <= 1) {
animatedImage = [[UIImage alloc] initWithData:data];
}
else {
// CVPixelBufferRef targets[count];
for (size_t i = 0; i < count; i++) {
CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);
if (!image) {
continue;
}
UIImage *uiImage = [UIImage imageWithCGImage:image scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp];
NSDictionary *dic = @{
@"duration":@([self sd_frameDurationAtIndex:i source:source]),
@"image":uiImage
};
[_images addObject:dic];
CGImageRelease(image);
}
}
CFRelease(source);
[self startGifDisplay];
}
- (float)sd_frameDurationAtIndex:(NSUInteger)index source:(CGImageSourceRef)source {
float frameDuration = 0.1f;
CFDictionaryRef cfFrameProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil);
NSDictionary *frameProperties = (__bridge NSDictionary *)cfFrameProperties;
NSDictionary *gifProperties = frameProperties[(NSString *)kCGImagePropertyGIFDictionary];
NSNumber *delayTimeUnclampedProp = gifProperties[(NSString *)kCGImagePropertyGIFUnclampedDelayTime];
if (delayTimeUnclampedProp) {
frameDuration = [delayTimeUnclampedProp floatValue];
}
else {
NSNumber *delayTimeProp = gifProperties[(NSString *)kCGImagePropertyGIFDelayTime];
if (delayTimeProp) {
frameDuration = [delayTimeProp floatValue];
}
}
if (frameDuration < 0.011f) {
frameDuration = 0.100f;
}
CFRelease(cfFrameProperties);
return frameDuration;
}
- (void)sd_GIFImagesWithLocalNamed:(NSString *)name {
if ([name hasSuffix:@".gif"]) {
name = [name stringByReplacingCharactersInRange:NSMakeRange(name.length-4, 4) withString:@""];
}
CGFloat scale = [UIScreen mainScreen].scale;
if (scale > 1.0f) {
NSData *data = nil;
if (scale>2.0f) {
NSString *retinaPath = [[NSBundle mainBundle] pathForResource:[name stringByAppendingString:@"@3x"] ofType:@"gif"];
data = [NSData dataWithContentsOfFile:retinaPath];
}
if (!data){
NSString *retinaPath = [[NSBundle mainBundle] pathForResource:[name stringByAppendingString:@"@2x"] ofType:@"gif"];
data = [NSData dataWithContentsOfFile:retinaPath];
}
if (!data) {
NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:@"gif"];
data = [NSData dataWithContentsOfFile:path];
}
if (data) {
[self sd_GifImagesWithLocalData:data];
}
}
else {
NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:@"gif"];
NSData *data = [NSData dataWithContentsOfFile:path];
if (data) {
[self sd_GifImagesWithLocalData:data];
}
}
}
@end