Jetpack Compose——Image使用Coli加载网络图片（包含GIF、SVG）

Image加载网络图片

 首先添加依赖：

    implementation("io.coil-kt:coil:1.4.0")
    implementation("io.coil-kt:coil-compose:1.4.0")

记得别忘记在manifest添加网络权限：

简单使用：

        Image(
            modifier = Modifier
                .size(200.dp, 150.dp),
            painter = rememberImagePainter("https://img-blog.csdnimg.cn/20210823085620179.jpeg"),
            contentDescription = null
        )

效果如图：

1，placeholder：占位图

在图片还没有完全显示之前所展示的本地资源图片

        Image(
            modifier = Modifier
                .size(300.dp, 200.dp),
            painter = rememberImagePainter(
                data = "https://img-blog.csdnimg.cn/20210823085620179.jpeg",
                builder = {
                    placeholder(R.drawable.head_icon)//占位图
                }),
            contentDescription = null
        )

效果如图：

2，Transitions：过渡效果

提供了两种过渡效果：

CrossfadeTransition 淡入淡出
Transition.NONE 在Target没有动画的情况下立即设置可绘制对象

        Image(
            modifier = Modifier
                .size(300.dp, 200.dp),
            painter = rememberImagePainter(
                data = "https://img-blog.csdnimg.cn/20210823085620179.jpeg",
                builder = {
                    placeholder(R.drawable.head_icon)//占位图
                    crossfade(true)//淡出效果
                }),
            contentDescription = null
        )

效果如图：

3，transformations：设置样式

CircleCropTransformation 圆形裁剪
RoundedCornersTransformation 圆角
GrayscaleTransformation 灰度 
BlurTransformation 高斯模糊 

@Composable
fun imageTest() {
    Column(
        modifier = Modifier
            .fillMaxWidth()
            .padding(10.dp)
            .verticalScroll(state = rememberScrollState())
    ) {
        Image(
            modifier = Modifier
                .size(120.dp, 120.dp),
            painter = rememberImagePainter(
                data = "https://img-blog.csdnimg.cn/20210823085620179.jpeg",
                builder = {
                    placeholder(R.drawable.head_icon)//占位图
                    crossfade(true)//淡出效果
                    transformations(CircleCropTransformation())//圆形效果
                }),
            contentDescription = null
        )
        Spacer(modifier = Modifier.padding(2.dp))
        Image(
            modifier = Modifier
                .size(120.dp, 120.dp),
            painter = rememberImagePainter(
                data = "https://img-blog.csdnimg.cn/20210823085620179.jpeg",
                builder = {
                    placeholder(R.drawable.head_icon)//占位图
                    crossfade(true)//淡出效果
                    transformations(RoundedCornersTransformation(0.8f))//圆角效果
                }),
            contentDescription = null
        )
        Spacer(modifier = Modifier.padding(2.dp))
        Image(
            modifier = Modifier
                .size(120.dp, 120.dp),
            painter = rememberImagePainter(
                data = "https://img-blog.csdnimg.cn/20210823085620179.jpeg",
                builder = {
                    placeholder(R.drawable.head_icon)//占位图
                    crossfade(true)//淡出效果
                    transformations(GrayscaleTransformation())//灰度效果
                }),
            contentDescription = null,
            contentScale = ContentScale.Crop
        )
        Spacer(modifier = Modifier.padding(2.dp))
        Image(
            modifier = Modifier
                .size(120.dp, 120.dp),
            painter = rememberImagePainter(
                data = "https://img-blog.csdnimg.cn/20210823085620179.jpeg",
                builder = {
                    placeholder(R.drawable.head_icon)//占位图
                    crossfade(true)//淡出效果
                    transformations(BlurTransformation(LocalContext.current, 0.1f, 2f))//高斯效果
                }),
            contentDescription = null,
            contentScale = ContentScale.Crop
        )
    }
}

效果如图：

 

Compose加载GIF图片

首先添加依赖：

implementation("io.coil-kt:coil-gif:1.4.0")

 使用：

        Image(
            modifier = Modifier
                .size(300.dp),
            painter = rememberImagePainter(
                data = "https://img-blog.csdnimg.cn/e6bb95f89399404195212196fdaf3964.gif",
                builder = {
                    decoder(GifDecoder())//添加GIF解码
                    placeholder(R.drawable.head_icon)//占位图
                    crossfade(true)//淡出效果
                }),
            contentDescription = null
        )

效果如图：

但是这里会出现一个问题：如果图片是jpg等格式的是没办法加载出来的，解决方案：

自己构建一个图片加载器赋值给imageLoader

        //自己构建图片加载器
        val imageLoaderM = ImageLoader.Builder(LocalContext.current)
            .componentRegistry {
                add(GifDecoder())
            }
            .build()
        Image(
            modifier = Modifier
                .size(300.dp),
            painter = rememberImagePainter(
                data = "https://img-blog.csdnimg.cn/e6bb95f89399404195212196fdaf3964.gif",
                imageLoader = imageLoaderM,
                builder = {
                    placeholder(R.drawable.head_icon)//占位图
                    crossfade(true)//淡出效果
                }),
            contentDescription = null
        )
        Spacer(modifier = Modifier.padding(2.dp))
        Image(
            modifier = Modifier
                .size(300.dp),
            painter = rememberImagePainter(
                data = "https://img-blog.csdnimg.cn/20210823085620179.jpeg",
                imageLoader = imageLoaderM,
                builder = {
                    placeholder(R.drawable.head_icon)//占位图
                    crossfade(true)//淡出效果
                }),
            contentDescription = null
        )

 效果如图：（可以加载出来）

Compose加载SVG图片

首先添加依赖

 implementation("io.coil-kt:coil-svg:1.4.0")

 使用：

        //自己构建图片加载器
        val imageLoaderM = ImageLoader.Builder(LocalContext.current)
            .componentRegistry {
                add(GifDecoder())//添加GIF图片解码
                add(SvgDecoder(LocalContext.current))//添加SVG图片解码
            }
            .build()
        Image(
            modifier = Modifier
                .size(300.dp),
            painter = rememberImagePainter(
                data = "https://coil-kt.github.io/coil/images/coil_logo_black.svg",
                imageLoader = imageLoaderM,
                builder = {
                    placeholder(R.drawable.head_icon)//占位图
                    crossfade(true)//淡出效果
                }),
            contentDescription = null
        )

效果如图：