显示从相机拍摄的图像时，Uri 为空答案

【问题标题】：Uri is null while displaying image taken from camera显示从相机拍摄的图像时，Uri 为空
【发布时间】：2014-01-18 12:07:48
【问题描述】：

您好，我需要从相机拍照并在屏幕上显示。

但我将 Uri 设为空。

我需要获取文件的绝对路径。

我的代码：

mintent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
mintent.putExtra(MediaStore.EXTRA_OUTPUT,
             MediaStore.Images.Media.EXTERNAL_CONTENT_URI.toString());
startActivityForResult(mintent, 1);


@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if ((data != null && !data.toString().equalsIgnoreCase("Intent {  }"))
            || requestCode == 1)
        switch (requestCode) {
        case 1:
            try {
                 Uri imageFileUri = data.getData();

                 Bitmap bitmap = (Bitmap) data.getExtras().get("data");
img2.setImageBitmap(bitmap);
}
}

请帮忙..

【问题讨论】：

标签： android android-camera android-image android-bitmap

【解决方案1】：

你的问题在这里：

mintent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
mintent.putExtra(MediaStore.EXTRA_OUTPUT,
             MediaStore.Images.Media.EXTERNAL_CONTENT_URI.toString());

您没有传递希望文件驻留的 URI。相反，您传递的是文件夹的 URI。相反，您应该将 URI 传递到您希望文件转到的位置。这是我几个月前做的一个项目的一个例子：

File lastSavedFile;

/**
 * IMPORTANT: this must be a directory readable by multiple apps (not private storage)
 * @return
 */
@SuppressLint("SimpleDateFormat")
private File getTempFile() {
    // Create an image file name
    String timeStamp =  new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "barfile_" + timeStamp + ".jpg";

    return new File(Environment.getExternalStorageDirectory(), imageFileName);
}

/**
 * Called when we want to take a picture
 * 
 * @param position
 */
private void launchTakePictureIntent(int position)
{
    Intent i=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

    lastSavedFile = getTempFile();
    i.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(lastSavedFile));
    startActivityForResult(i, position);
}

/**
 * Returns from the camera intent, hopefully with a picture
 */
@Override
protected void onActivityResult(int position, int resultCode, Intent intent) {

    super.onActivityResult(position, resultCode, intent);

    if (resultCode == RESULT_OK) {
        Uri imageUri = Uri.fromFile(lastSavedFile);
        Bitmap fullBitmap;
        try {
            fullBitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), imageUri);
        } catch (Exception e) {
            Log.e(TAG, e.toString(), e);
            return;
        }
        ...

【讨论】：

【解决方案2】：

这是我用来获取图片 Uri 的代码。

  private Bitmap photo;
  private File pic;
  private Uri uri;

  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1) {
      photo = (Bitmap) data.getExtras().get("data");

      try {
        File root = Environment.getExternalStorageDirectory();
        if (root.canWrite()) {
          pic = new File(root, "pic.png");
          FileOutputStream out = new FileOutputStream(pic);

          photo.compress(CompressFormat.PNG, 100, out);

          out.flush();
          out.close();
        }
      } catch (IOException e) {
        Log.e("BROKEN", "Could not write file " + e.getMessage());
      }

      // This is the uri you are looking for.
      uri = Uri.fromFile(pic);
    }
  }

PS：如果您不想声誉不佳，请不要忘记接受上一个问题中的答案：onActivityResult is not calling after taking camera picture。

【讨论】：