节约问题＆amp;打开一个BitMap文件

Question

在这段代码中，我试图：

1. 从ImageView获取位图
2. 将其另存为“er.png”
3. 然后加载它并将其分配给另一个ImageView

这是我的代码......但是它一直在触发它无法写入的异常...任何想法可能导致它？也许它需要一些权限？

////// GET FROM IV /////////////////////////////////////
        ImageView iv = (ImageView)findViewById(R.id.ivDon);
        Drawable draw = iv.getBackground();
        Bitmap bm = ((BitmapDrawable)draw).getBitmap();
        Bitmap bmHue = Hue(bm,180);

        //////////////////////////// SAVE ///////////
        Bitmap bbicon = bmHue;

        String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
        OutputStream outStream = null;
        File file = new File(extStorageDirectory, "er.PNG");
        try {
         outStream = new FileOutputStream(file);
         bbicon.compress(Bitmap.CompressFormat.PNG, 100, outStream);
         outStream.flush();
         outStream.close();
        }
        catch(Exception e)
        {Toast.makeText(this, "error writing :/", 5000).show();} // <- this exception fires.

        ///////////////////////////// LOAD //////////////  
        java.io.FileInputStream in = null;
        try {
            in = openFileInput("er.PNG");
        } catch (FileNotFoundException e)
        {Toast.makeText(this, "error reading :/", 5000).show();}

        ////////////////////////////// ASSIGN ///////////////
        ImageView iv1 = (ImageView)findViewById(R.id.iv01);
        iv1.setImageBitmap(BitmapFactory.decodeStream(in));

谢谢！

Answer 1

尝试添加：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

到清单

Answer 2

您的清单中是否有权限WRITE_EXTERNAL_STORAGE？

Answer 3

尝试在清单中添加此内容：uses-permission android：name =“android.permission.WRITE_EXTERNAL_STORAGE”