Android 如何从URI中获取图像大小

发布于11月17日

我通过以下方式获取图像URI

val launcher = rememberLauncherForActivityResult(ActivityResultContracts.PickVisualMedia()){uri = it}

launcher.launch(PickVisualMediaRequest(ActivityResultContracts.PickVisualMedia.ImageOnly))

我需要得到这个图像的大小我试着用

val painter = rememberAsyncImagePainter(uri)
return painter.intrinsicSize

但这将返回未指定的大小

和

val options = BitmapFactory.Options()
options.inJustDecodeBounds = true
BitmapFactory.decodeFile(uri.path, options)
Log.d("MyLog", "${options.outWidth}, ${options.outHeight}")
return IntSize(options.outWidth, options.outHeight)

但它返回IntSize(0，0)

How can I get width 和 height of image?

推荐答案

要从Uri获得图像的宽度和高度，您可以使用ContentResolver打开InputStream，然后使用BitmapFactory解码尺寸.下面是一个例子:

import android.content.ContentResolver
import android.graphics.BitmapFactory
import android.net.Uri
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import java.io.IOException

suspend fun getImageSize(contentResolver: ContentResolver, uri: Uri): Pair<Int, Int>? {
    return withContext(Dispatchers.IO) {
        var inputStream = try {
            contentResolver.openInputStream(uri)
        } catch (e: IOException) {
            null
        }

        var options: BitmapFactory.Options? = null
        var result: Pair<Int, Int>? = null

        try {
            options = BitmapFactory.Options()
            options.inJustDecodeBounds = true
            BitmapFactory.decodeStream(inputStream, null, options)
            result = Pair(options.outWidth, options.outHeight)
        } finally {
            inputStream?.close()
        }

        result
    }
}

然后，您可以按如下方式使用此函数:

val size = getImageSize(contentResolver, uri)
if (size != null) {
    val width = size.first
    val height = size.second
    // Do something with width and height
} else {
    // Handle the case where the size couldn't be determined
}

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