如何在Android ImageView中从dataurl加载图像？

Question

我有以下数据URL：

data:image/png;base64,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

有没有办法在ImageView中加载dataUrl？

- Jyothish

Answer 1

首先，您需要将Base64编码的字符串转换为位图。以下代码片段来自链接问题：

byte[] decodedString = Base64.decode("Your Base64 String", Base64.DEFAULT);
Bitmap bitMap = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);

当完成这个操作后，你会得到一个位图 bitmap。假设你的imageView已经定义为R.id.image_view，那么你只需像对待其他位图一样处理即可：

ImageView imageView;
imageView = (ImageView) findViewById(R.id.image_view);
imageView.setImageBitmap(bitmap);

- Einar Sundgren

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在进行上述解码时出现了内存不足错误。 - Jyothish

@Jyothish 你能发布一下堆栈跟踪吗？ - Einar Sundgren

Answer 2

由于我遇到了以下错误：

java.lang.IllegalArgumentException: bad base-64

我使用了以下解决方法：

import java.io.ByteArrayInputStream
import java.io.InputStream
import android.util.Base64

...
val imageData: ByteArray = Base64.decode(dataUri.substring(dataUri.indexOf(",") + 1), Base64.DEFAULT)
val inputStream: InputStream = ByteArrayInputStream(imageData)
val bitmap: Bitmap = BitmapFactory.decodeStream(inputStream)

imageViewComponent.setImageBitmap(bitmap)

也许能帮助某些人。

- alexrnov

Answer 3

如果您取输入的Base64部分，可以通过以下方式轻松将其转换为位图：

byte[] decodedString = Base64.decode("your base64 string", Base64.DEFAULT); 
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);

- Ed Holloway-George

Answer 4

只需使用 Base64.decode() 方法对 Base64 图像编码进行解码，以接收字节数组，然后使用 BitmapFactory.decodeByteArray() 方法创建 Bitmap。

- Egor

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我已经将DataUrl存储在一个变量中，不需要从数据库或网络获取。我需要在AsyncTask中进行解码吗？还是在主线程中进行会影响性能？ - Jyothish

Answer 5

将base64字符串存储在String变量中并解码

String encodedImage;// 在此字符串中设置base64字符串值 byte[] decodedString = Base64.decode(encodedImage, Base64.DEFAULT); Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);

- Zeeshan Khan