方法'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap $ CompressFormat，int，java.io.OutputStream) [英] method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)

问题描述

我的代码中出现此错误，有人通知我如何解决?谢谢所有能提供帮助的人.

I am having this error in my code, someone informs me how to solve it? Thank you to everyone who can help.

java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference
        at map.app.fragments.ReportFragment.putImgToBytearray(ReportFragment.kt:177)

线路错误

bitmap.compress(Bitmap.CompressFormat.JPEG, 70, stream)

代码

private fun putImgToBytearray(): ByteArray {
    val stream = ByteArrayOutputStream()
    val drawable = this.imgThumb!!.drawable as BitmapDrawable
    val bitmap = drawable.bitmap
    bitmap.compress(Bitmap.CompressFormat.JPEG, 70, stream)
    return stream.toByteArray()
}

onActivityResult代码

onActivityResult code

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (requestCode == IMAGE_PICK_CODE && resultCode == RESULT_OK) {


        try {

            //Getting the Bitmap from Gallery
            val bitmap = MediaStore.Images.Media.getBitmap(context.contentResolver, this.imageUri) as Bitmap?
            this.imgThumb!!.setImageBitmap(bitmap)
            this.pictureTaken = true
        } catch (e:IOException) {
            e.printStackTrace()
        }
    } else {
        Toast.makeText(context, "Error loading image", Toast.LENGTH_LONG)
    }
}

从图库中选择图像的方法.只是改编

method for select image from gallery. it's just an adaptation

fun openCamera() {
    try {
        val imageFile = createImageFile()
        val callCameraIntent =  Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
        if(callCameraIntent.resolveActivity(activity.packageManager) != null) {
            val authorities = activity.packageName + ".fileprovider"
            this.imageUri = FileProvider.getUriForFile(context, authorities, imageFile)
            callCameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri)
            startActivityForResult(callCameraIntent, IMAGE_PICK_CODE)
        }
    } catch (e: IOException) {
        Toast.makeText(context, "Could not create file!", Toast.LENGTH_SHORT).show()
    }
}

推荐答案

我敢打赌MediaStore.Images.Media.getBitmap无法正确获取位图并返回null.

I bet that MediaStore.Images.Media.getBitmap does not get the bitmap properly and returns null.

因此，如果您删除了MediaStore.Images.Media.getBitmap(context.contentResolver, this.imageUri) as Bitmap?中的?，您将得到一个运行时异常，正如您先前的问题所断言的那样.

So if you remove the ? in MediaStore.Images.Media.getBitmap(context.contentResolver, this.imageUri) as Bitmap? you will get a runtime exception as your previous question asserts.

因此将演员表更改为:

MediaStore.Images.Media.getBitmap(context.contentResolver, this.imageUri) as Bitmap

为确保您永远不会获得空位图，请返回以调查getBitmap方法

To make sure you never get a null bitmap then com back to investigate getBitmap method

我不知道createImageFile方法的作用，但我建议您简单地执行以下操作以测试其是否有效:

I have no idea what does the createImageFile method do, but I suggest you to simply do the following to test if it is working:

MediaStore.Images.Media.getBitmap(this.getContentResolver(), Uri.parse("file://"+uri));

最后我建议不要使用MediaStore.Images.Media.getBitmap.

Finally I advice against of using of MediaStore.Images.Media.getBitmap at all.

请参见已弃用.切换到图片加载库，或使用 ImageDecoder#createSource(ContentResolver，Uri)

See Its deprecated. switch to image loading libraries or use ImageDecoder#createSource(ContentResolver, Uri)

在提到的链接中有一些指南.像这样一个:

There are guides in the mentioned link. Like this one:

public static Bitmap decodeBitmap (ImageDecoder.Source src)

还要确保在工作线程中执行这些操作.

Also make sure to do these kin of stuff in a worker thread.

这篇关于方法'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap $ CompressFormat，int，java.io.OutputStream)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！