java - Android:如何从字符串创建位图？

Question

我想将字符串中的一些文本另存为图像。现在我有以下代码:

private void saveImage(View view){
    String mPath = Environment.getExternalStorageDirectory().toString() + "/" + "spacitron.png";  
    String spacitron = "spacitron";
    Bitmap bitmap = BitmapFactory.decodeByteArray(spacitron.getBytes(), 0, spacitron.getBytes().length*5);
    OutputStream fout = null;
    File imageFile = new File(mPath);

    try {
        fout = new FileOutputStream(imageFile);
        //This line throws a null pointer exception
        bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fout);
        fout.flush();
        fout.close();
        } catch (FileNotFoundException e) {
        } catch (IOException e) {
        }
    }

但这并没有创建位图，而是抛出了一个空指针异常。如何将字符串保存为位图？

Answer 1

创建 Canvas 对象并在 Canvas 上绘制文本。然后将 Canvas 保存为位图

Bitmap toDisk = Bitmap.createBitmap(w,h,Bitmap.Config.ARGB_8888);
canvas.setBitmap(toDisk);


canvas.drawText(message, x , y, paint);

toDisk.compress(Bitmap.CompressFormat.JPEG, 100, new FileOutputStream(new File("/mnt/sdcard/viral.jpg")));