代码

Question

代码

public Bitmap StringToBitMap(String encodedString){          
   try{              
         byte [] encodeByte=Base64.decode(encodedString,Base64.DEFAULT);               
         Bitmap bitmap=BitmapFactory.decodeByteArray(encodeByte, 0, encodeByte.length);
         return bitmap;
       }catch(Exception e){
           e.getMessage();
           return null;
       } 
}

这总是返回null，即使我给它编码64（utf-8）字符串---＆gt; aGVsbG8 =

为什么这种情况发生在任何人都有想法.. ??我做错了可以任何人建议我......

Answer 1

我认为问题在于您尝试将base64字符串解码为Bitmap，但实际上您只是想将其解码为字符串。这是执行此操作的代码：

String decodeBase64String(String encodedString)
{
    byte[] data = Base64.decode(encodedString, Base64.DEFAULT);
    return new String(data, "UTF-8");
}

（假设采用UTF-8编码）

如果你用这样的测试字符串调用这个函数：

String result = decodeBase64String("aGVsbG8=");

然后结果将是“你好”。

以下是将文本转换为位图的方法：

Bitmap textToBitmap(String text)
{
     Paint paint = new Paint();
     paint.setColor(Color.WHITE);
     paint.setStrokeWidth(12);
     Rect bounds = new Rect();
     paint.getTextBounds(text, 0, text.length(), bounds);
     Bitmap bitmap = Bitmap.createBitmap(bounds.width(), bounds.height(), Bitmap.Config.ARGB_8888);
     Canvas canvas = new Canvas(bitmap);
     canvas.drawText(text, 0, 0, paint);
     return bitmap;
}

因此，您可以将base64编码的文本转换为如下位图：

String result = decodeBase64String("aGVsbG8=");
Bitmap bitmap = textToBitmap(result);

或者你可以这样做：

Bitmap bitmap = textToBitmap("hello");

Answer 2

您可以使用其他一些内置方法恢复您的代码。

  String base="****Base64 string values of some image******”;
  byte[] imageAsBytes = Base64.decode(base.getBytes(), Base64.DEFAULT);
  ImageView image = (ImageView)this.findViewById(R.id.imageView1);
  image.setImageBitmap(
  BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length)

Answer 3

试试这个，可能对你有帮助..

String base =＆＃34; ****你的Base64字符串******“;

byte [] imageBytes = Base64.decode（base.getBytes（），Base64.DEFAULT）; ImageView.setImageBitmap（BitmapFactory.decodeByteArray（imageBytes，0，imageBytes.length）

Answer 4

我检查了一下。它工作正常。

可能是你传球错误＆＃34; encodedString＆＃34;。

测试以下代码

String strBase64 =＆＃34; / 9j / 4AAQSkZJRgABAQAAAQABAAD / 2wBDAFA3PEY8MlBGQUZaVVBfeMiCeG5uePWvuZHI ////////////////////////////////// ////////////////// 2wBDAVVaWnhpeOuCguv /////////////////////////////// ////////////////////////////////////////// wAARCABeAJoDASIAAhEBAxEB / 8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL / 8QAtRAAAgEDAwIEAwUFBAQAAAF9AQIDAAQRBRIhMUEGE1FhByJxFDKBkaEII0KxwRVS0fAkM2JyggkKFhcYGRolJicoKSo0NTY3ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqDhIWGh4iJipKTlJWWl5iZmqKjpKWmp6ipqrKztLW2t7i5usLDxMXGx8jJytLT1NXW19jZ2uHi4 + Tl5ufo6erx8vP09fb3 + PN6 / 8QAHwEAAwEBAQEBAQEBAQAAAAAAAAECAwQFBgcICQoL / 8QAtREAAgECBAQDBAcFBAQAAQJ3AAECAxEEBSExBhJBUQdhcRMiMoEIFEKRobHBCSMzUvAVYnLRChYkNOEl8RcYGRomJygpKjU2Nzg5OkNERUZHSElKU1RVVldYWVpjZGVmZ2hpanN0dXZ3eHl6goOEhYaHiImKkpOUlZaXmJmaoqOkpaanqKmqsrO0tba3uLm6wsPExcbHyMnK0tPU1dbX2Nna4uPk5ebn6Onq8vP09fb3 + PN6 / 9oADAMBAAIRAxEAPwCsqgrnFLsHpQn3RTqoY3YPSjYPSnUUAN2L6UbF9KfRQAzYvpRsX0p9FADNi + lGxfSn0UAM2L6UbB6U / FJQIbsHpRsHpTqKAG7R6Um0elPpKYDdg9Kd5YpVqbhEU7QSfWiyIbK5THao6suBk4 BA9DVWlJDi7kyfcFOpqH5BS7vagsWik3UbqAFpaTNLmgAopNwo3CgBaQ5A460m + lQlnAoewAM9 + tFDkhyOKbuPtQtgHUUmaOaYC0lJ83rRz60CHDinrIyjAIx7iosmjJoE1cezZySck1WqbJqGlIErD1 + 7S0L90UUFBSU6jFAWAHFGaMUmKAsJRS4ooASpIfv / AIUypYPvE + 1J7ANlHz1HUs33h9KaKa2AbzTlNLg9qAGphYUmmYJqTaaNppBYjCmnY9aXbS4oCw3FQVZxVakxEi4x1pwXPTmohTgSpyKVxpknlt6UbG9KesyEc8GpQAeRTuXoQhGPajY3pU + KMUXAh8qjyanoouBX8k0oAjVgTyanqGSMs / Hf3pMTEKhwuDnAo8oUsaFX5 / nUuKECIdnvQFI71Nim4p3HYbg0Yp + KTFAhmKMU / FJigBlVqsuwUc1WoZLJYdufmp8yoeU49qgU4pSxPGaRFtRKnhnCrtYE1BUsRCg5HPrQVexI1yv8IP41JE + 9MkjPeqbdaccKqsrHd3pD5i7SVXFw / dc09Zlbvg + 9LUu6JGIUc0wOu4k8YFJNygP5VEIc9wD70C6kxdQT705SGGRVfyvQg / SpYxtTIPFAIkpKjaUKM5z + NM88 / wB2mO6J6aWCjkiq6uzuAWIzTW + 8cnPvTJ5h7TOTxwKjyT3pzMCAABxTaCb3DvzTadSUAApaQHFLuoAKATjFG6jd7UALg0nWjdRu9qBCjIowaTdRuoAdkjHtT9ynlsk1Fuo3Uhkm4AfLkUm44I9aZuo3UAKcmg5OKTdRupiAZFHJo3UbqBhiijdSZoAWm0uaKAP / 2Q ==＆＃34 ;;

    Log.d("base64 String: ", strBase64);


    byte[] decodedString = Base64.decode(strBase64, Base64.DEFAULT);
    Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length); 
    test.setImageBitmap(decodedByte);

在Android中将base64字符串解码为位图

代码

4 个答案: