Question

我正在通过以下方式将Url转换为Uri

imgUrl = intent.getStringExtra(getString(R.string.selected_image));
            Log.d(TAG, "Image URL" + imgUrl);
                imageUri = Uri.parse(imgUrl) ;
            Log.d(TAG, "Image URI" + imageUri);

然后将其传递给此函数

 BackgroundImageResize backgroundImageResize = new BackgroundImageResize(bitmap);
           backgroundImageResize.execute(imageUri);

和BackgroundImageResize将参数视为

public class BackgroundImageResize extends AsyncTask<Uri, Integer, byte[]>

现在这个方法

Log.d(TAG, "doInBackground: megabytes before compression: " + mBitmap.getByteCount() / 1000000 );
        bytes = getBytesFromBitmap(mBitmap, 100);
        Log.d(TAG, "doInBackground: megabytes before compression: " + bytes.length / 1000000 );

正在返回此错误

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getByteCount()' on a null object reference

在之前与一个非常聪明的人的讨论中，可以得出结论，也许，Uri是不正确的

如何传递正确的Uri？

这是doInBackground（）以防万一

@Override
    protected byte[] doInBackground(Uri... params) {
        Log.d(TAG, "doInBackground: started.");

        if(mBitmap == null){
            try{
                mBitmap = MediaStore.Images.Media.getBitmap(NextActivity.this.getContentResolver(), params[0]);
            }catch (IOException e){
                Log.e(TAG, "doInBackground: IOException: " + e.getMessage());
            }
        }
        byte[] bytes = null;
        Log.d(TAG, "doInBackground: megabytes before compression: " + mBitmap.getByteCount() / 1000000 );
        bytes = getBytesFromBitmap(mBitmap, 100);
        Log.d(TAG, "doInBackground: megabytes before compression: " + bytes.length / 1000000 );
        return bytes;
    }

我怀疑这行代码

mBitmap = MediaStore.Images.Media.getBitmap(NextActivity.this.getContentResolver(), params[0]);

没有做它的工作：P

Answer 1

请在doInBackGround（）中添加带有++++++++++++++++++++++++++++++++++++++

@Override
protected byte[] doInBackground(Uri... params) {
    Log.d(TAG, "doInBackground: started.");

    Log.d(TAG, "+++++++++++++ params[0]: " + params[0]);

    if(mBitmap == null){
        try{
            mBitmap = MediaStore.Images.Media.getBitmap(NextActivity.this.getContentResolver(), params[0]);
        }catch (IOException e){
            Log.e(TAG, "doInBackground: IOException: " + e.getMessage());
        }
    }

    Log.d(TAG, "+++++++++++++ mBitmap: " + mBitmap);

    byte[] bytes = null;
    Log.d(TAG, "doInBackground: megabytes before compression: " + mBitmap.getByteCount() / 1000000 );
    bytes = getBytesFromBitmap(mBitmap, 100);
    Log.d(TAG, "doInBackground: megabytes before compression: " + bytes.length / 1000000 );
    return bytes;
}

Answer 2

事实证明，Locdoc01一直都是正确的，Uri是错的，所有我必须做的就是将文件：//附加到url，然后再将其解析为Uri ......

像这样

imgUrl = intent.getStringExtra(getString(R.string.selected_image));
ImgUrlAppended = "file://" + imgUrl;
Log.d(TAG, "Image URL" + imgUrl);
imageUri = Uri.parse(ImgUrlAppended) ;
Log.d(TAG, "Image URI" + imageUri);

图片现在压缩了！

感谢所有支持，StackOverflow！希望这有助于某人

将Url转换为Uri并将其传递给AsyncTask＆lt;＆gt;

2 个答案: