weex改变image标签src

Question

<template>
    <div>
        <image :src="src" style="width:80px;height:80px;" @click="tap"></image>
    </div>
</template>
<script>
export default {
    data() {
        return {
            src: "xcassets:tab_icon_home"
        }
    },
    methods: {
        tap() {
            this.src = "xcassets:tab_icon_home_pre"
        }
    }
}
</script>

自定义图片加载

- (id <WXImageOperationProtocol>)downloadImageWithURL:(NSString *)url imageFrame:(CGRect)imageFrame userInfo:(NSDictionary *)userInfo completed:(void (^)(UIImage *image, NSError *error, BOOL finished))completedBlock {
    if ([url hasPrefix:@"//"]) {
        url = [@"http:" stringByAppendingString:url];
    }
    if ([url hasPrefix:@"xcassets:"]) {
        UIImage *image = [UIImage imageNamed:[url substringFromIndex:9]];
        completedBlock(image, nil, YES);

        return (id <WXImageOperationProtocol>) image;
    }
    NSURL *imgUrl = [NSURL URLWithString:url];
    return (id <WXImageOperationProtocol>) [[[SDWebImageManager sharedManager] imageDownloader] downloadImageWithURL:imgUrl options:0 progress:^(NSInteger receivedSize, NSInteger expectedSize, NSURL *_Nullable targetURL) {
    }                                                                                                      completed:^(UIImage *_Nullable image, NSData *_Nullable data, NSError *_Nullable error, BOOL finished) {
        if (completedBlock) {
            completedBlock(image, error, finished);
        }
    }];
}

点击图片后报错

2017-10-26 14:00:45.807053+0800 colavideo[4753:1906658] \^[[fg0,128,0; <Weex>[debug]WXJSCoreBridge.m:274, callUpdateAttrs...0, 20, {
    src = "xcassets:tab_icon_home_pre";
} \^[[;
2017-10-26 14:00:45.815417+0800 colavideo[4753:1906629] -[UIImage cancel]: unrecognized selector sent to instance 0x1c40bb540
2017-10-26 14:00:45.815886+0800 colavideo[4753:1906629] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIImage cancel]: unrecognized selector sent to instance 0x1c40bb540'
*** First throw call stack:
(0x186e37d38 0x18634c528 0x186e451f8 0x186e3d6e4 0x186d230dc 0x104415918 0x104414134 0x104e4d49c 0x104e4d45c 0x104e5c110 0x104e509a4 0x104e5d104 0x104e64100 0x186a62fe0 0x186a62c30)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

自己解决了：同时实现WXImgLoaderProtocol和WXImageOperationProtocol
WXImgLoaderDefaultImpl：

#import "WXImgLoaderDefaultImpl.h"
#import <SDWebImage/SDWebImageManager.h>

@implementation WXImgLoaderDefaultImpl

- (id <WXImageOperationProtocol>)downloadImageWithURL:(NSString *)url imageFrame:(CGRect)imageFrame userInfo:(NSDictionary *)userInfo completed:(void (^)(UIImage *image, NSError *error, BOOL finished))completedBlock {
    if ([url hasPrefix:@"//"]) {
        url = [@"http:" stringByAppendingString:url];
    }
    if ([url hasPrefix:@"xcassets:"]) {
        UIImage *image = [UIImage imageNamed:[url substringFromIndex:9]];
        completedBlock(image, nil, YES);
        return self;
    }
    NSURL *imgUrl = [NSURL URLWithString:url];
    [[[SDWebImageManager sharedManager] imageDownloader] downloadImageWithURL:imgUrl options:0 progress:^(NSInteger receivedSize, NSInteger expectedSize, NSURL *_Nullable targetURL) {
    }                                                                                                      completed:^(UIImage *_Nullable image, NSData *_Nullable data, NSError *_Nullable error, BOOL finished) {
        if (completedBlock) {
            completedBlock(image, error, finished);
        }
    }];
    return self;
}

-(void)cancel{
    
}
@end