如何将位图保存到android画廊 [英] how to save bitmap to android gallery

问题描述

不幸的是，我发现的解决方案不适用于 android 5.1.1.我有一个名为 source 的位图.我需要将它直接保存到我手机的图库中.我的清单包含 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>你能给我一个工作方法来做到这一点吗?

unfortunately the solutions I've found didn't work on android 5.1.1. I have a bitmap called source. I need to save it directly to my phone's gallery. My manifest contains <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> Can you give me a working method to do this?

推荐答案

在 API 29 (Android Q) 之前有几种不同的方法可以做到，但所有这些都涉及到一个或几个随 Q 弃用的 API.在 2019 年，这是一种既向后兼容又向前兼容的方法:

There were several different ways to do it before API 29 (Android Q) but all of them involved one or a few APIs that are deprecated with Q. In 2019, here's a way to do it that is both backward and forward compatible:

(因为是 2019 年所以我会用 Kotlin 写)

(And since it is 2019 so I will write in Kotlin)

    /// @param folderName can be your app's name
    private fun saveImage(bitmap: Bitmap, context: Context, folderName: String) {
        if (android.os.Build.VERSION.SDK_INT >= 29) {
            val values = contentValues()
            values.put(MediaStore.Images.Media.RELATIVE_PATH, "Pictures/" + folderName)
            values.put(MediaStore.Images.Media.IS_PENDING, true)
            // RELATIVE_PATH and IS_PENDING are introduced in API 29.

            val uri: Uri? = context.contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
            if (uri != null) {
                saveImageToStream(bitmap, context.contentResolver.openOutputStream(uri))
                values.put(MediaStore.Images.Media.IS_PENDING, false)
                context.contentResolver.update(uri, values, null, null)
            }
        } else {
            val directory = File(Environment.getExternalStorageDirectory().toString() + separator + folderName)
            // getExternalStorageDirectory is deprecated in API 29

            if (!directory.exists()) {
                directory.mkdirs()
            }
            val fileName = System.currentTimeMillis().toString() + ".png"
            val file = File(directory, fileName)
            saveImageToStream(bitmap, FileOutputStream(file))
            if (file.absolutePath != null) {
                val values = contentValues()
                values.put(MediaStore.Images.Media.DATA, file.absolutePath)
                // .DATA is deprecated in API 29
                context.contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
            }
        }
    }

    private fun contentValues() : ContentValues {
        val values = ContentValues()
        values.put(MediaStore.Images.Media.MIME_TYPE, "image/png")
        values.put(MediaStore.Images.Media.DATE_ADDED, System.currentTimeMillis() / 1000);
        values.put(MediaStore.Images.Media.DATE_TAKEN, System.currentTimeMillis());
        return values
    }

    private fun saveImageToStream(bitmap: Bitmap, outputStream: OutputStream?) {
        if (outputStream != null) {
            try {
                bitmap.compress(Bitmap.CompressFormat.PNG, 100, outputStream)
                outputStream.close()
            } catch (e: Exception) {
                e.printStackTrace()
            }
        }
    }

另外，在调用这个之前，你需要先有WRITE_EXTERNAL_STORAGE.

Also, before calling this, you need to have WRITE_EXTERNAL_STORAGE first.

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