反应本机中的图像调整

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Ran into the same problem and was able to tweak the resize mode until I found something I was happy with. Alternative approaches include:

Reduce the size of the Static Resource using an image editor
Add a transparent border to the static resource using an image editor
Use a Network Resource at the expense of UX

To prevent loss of quality while tweaking images consider working with vector graphics so you can experiment with different sizes easily. Inkscape is free tool and works well for this purpose.

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Use Resizemode with 'cover' or 'contain' and set the height and with of the Image.

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image auto fix the View

image: {
flex: 1,
width: null,
height: null,
resizeMode: 'contain'
}

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I adjust your answer a bit (shixukai)

image: {
flex: 1,
width: 50,
height: 50,
resizeMode: 'contain' }

When I set to null, the image wont show at all. I set to certain size like 50

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This worked for me,

image: {
width: 200,
height:220,
resizeMode: 'cover'
}

You can also set your resizeMode: 'contain'. I defined the style for my network images as:

<Image
source=\{\{uri:rowData.banner_path}}
style=\{\{
width: 80,
height: 80,
marginRight: 10,
marginBottom: 12,
marginTop: 12}}
/>

If you are using flex, use it in all the components of parent View, else it is redundant with height: 200, width: 220.

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After trying some combinations, I get this working like this:

image: {
width: null,
resizeMode: 'contain',
height: 220
}

Specifically in that order. I hope this can be helpful for someone. (I know that is an old question)

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Here's my solution if you know the aspect ratio, which you can either get from the image metadata or prior knowledge. This fills the whole width of the screen, but that, of course, can be adjusted.

function imageStyle(aspect)
{
//Include any other style requirements in your returned object.
return {alignSelf: "stretch", aspectRatio: aspect, resizeMode: 'stretch'}
}

This looks a bit nicer than contain, and takes less finessing with sizes, and it will adjust the height to maintain the proper aspect ratio so your images don't look skewed. Using contain will preserve the aspect ratio but will scale it to fit your other style requirements, which may drastically shrink the image.

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This worked for me:

image: {
flex: 1,
aspectRatio: 1.5,
resizeMode: 'contain',


}

aspectRatio is just width/height (my image is 45px wide x 30px high).

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This worked for me:

image: {
flex: 1,
width: 900,
height: 900,
resizeMode: 'contain'
}

Just need to make sure that the width and height are bigger than you need as it is limited to what you set.

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In my case I could not set 'width' and 'height' to null because I'm using TypeScript.

The way I fixed it was by setting them to '100%':

backgroundImage: {
flex: 1,
width: '100%',
height: '100%',
resizeMode: 'cover',
}

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{ flex: 1, resizeMode: 'contain' } worked for me. I didn't need the aspectRatio

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Try this: (for more details click here)

image: { flex: 1, height: undefined, width: undefined, resizeMode: 'contain' }

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Hey to make your image responsive is simple: here is an article i wrote about it. https://medium.com/@ashirazee/react-native-simple-responsive-images-for-all-screen-sizes-with-flex-69f8a96dbc6f

you can simply do this and it will scale

container: {
width: 200,
height: 220
},// container holding your image




image: {
width: '100%',
height: '100%',
resizeMode: cover,
},
});

this is because the container which holds the image determines the height and width, so by using percentages you will be able to make your image responsive to all screens size.

here is another example:

<View style=\{\{
width: 180,
height: 200,
aspectRatio: 1 * 1.4,
}}>
<Image
source=\{\{uri : item.image.url}}
style=\{\{
resizeMode: ‘cover’,
width: ‘100%’,
height: ‘100%’
}}
/>
</View>

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**After setting the width and the height of the image then use the resizeMode property by setting it to cover or contain.The following blocks of code translate from normal css to react-native StyleSheet

// In normal css
.image{
width: 100px;
height: 100px;
object-fit: cover;
}


// in react-native StyleSheet
image:{
width: 100;
height: 100;
resizeMode: "cover";
}

OR object-fit contain

// In normal css


.image{
width: 100px;
height: 100px;
object-fit: contain;
}


// in react-native StyleSheet
image:{
width: 100;
height: 100;
resizeMode: "contain";
}

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{ flex: 1, height: undefined, width: undefined, resizeMode: 'contain' }

If you are using these attributes in your style prop in the <Image /> and the image is disappeared.

Put your image into a <View> tag. Like this:

<View
style=\{\{
width: '100%',
height: '30%'
}}
>
<Image
source={require('../logo.png')}
style=\{\{
flex: 1,
height: undefined,
width: undefined,
resizeMode: 'contain'
}}
resizeMode={'cover'}
/>
</View>

Give your view the width and height you want.

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I tried other solutions and I didn't get the result I was looking for. This works for me.

<TouchableOpacity onPress={() => navigation.goBack()} style=\{\{ flex: 1 }}>
<Image style=\{\{ height: undefined, width: undefined, flex: 1 }}
source=\{\{ uri: link }} resizeMode="contain"
/>
</TouchableOpacity>

Note I needed to set this as property of image tag than in css.

resizeMode="contain"

Also note that, you need to set flex: 1 on your parent container. For my component, TouchableOpacity is the root of the component.

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I got the image Size and set it to max 130 width and 30 height.

const [imageSize, setImageSize] = useState();
Image.getSize(url, (width, height) => {
setImageSize(logoSize(width, height));
});
...
<Image style={imageSize ?? initialSize} source=\{\{uri: url}} />
...




const logoSize = (width, height) => {
var maxWidth = 110;
var maxHeight = 30;


if (width >= height) {
var ratio = maxWidth / width;
var h = Math.ceil(ratio * height);


if (h > maxHeight) {
// Too tall, resize
var ratio = maxHeight / height;
var w = Math.ceil(ratio * width);
var ret = {
width: w,
height: maxHeight,
};
} else {
var ret = {
width: maxWidth,
height: h,
};
}
} else {
var ratio = maxHeight / height;
var w = Math.ceil(ratio * width);


if (w > maxWidth) {
var ratio = maxWidth / width;
var h = Math.ceil(ratio * height);
var ret = {
width: maxWidth,
height: h,
};
} else {
var ret = {
width: w,
height: maxHeight,
};
}
}


return ret;
};

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To avoid the huge padding when resizing using 'contain', use 'stretch' with a height and an aspectRatio (that idea is from this answer).

{ height: '20%', aspectRatio: 1, resizeMode: 'stretch' }

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this worked for me

height: undefined,
width: undefined,
flex: 1,
resizeMode: "contain",

wrap the image in a View with flex:1