Android 上传图像应用程序在模拟器上工作正常，但无法在测试手机上上传图像

上传图像应用程序：它在模拟器上工作正常，但无法在测试手机上上传图像。它从图库中选择图片，但不在Imageview中显示任何内容。

 public class Uploadimage extends Activity {
        public static int requestCode=1;
        Button b1;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_uploadimage);     

         b1= (Button) findViewById(R.id.button1);
         b1.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                Intent i=new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                startActivityForResult(i, requestCode);         
            }
        });
        }
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
      {
        super.onActivityResult(requestCode, resultCode, data) ;
        if (requestCode==1 && resultCode==RESULT_OK) {
            Uri image = data.getData();
            String [] filepath = {MediaStore.Images.Media.DATA};

            Cursor cursor = getContentResolver().query(image, filepath, null, null, null);
            cursor.moveToFirst();

            int column = cursor.getColumnIndex(filepath[0]);
            String path= cursor.getString(column);
            cursor.close();
            ImageView imageview= (ImageView) findViewById(R.id.imageView1);
            imageview.setImageBitmap(BitmapFactory.decodeFile(path));           
        }
      }
    }

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如果您从手机获取内容，则必须在清单文件中写入以下代码：

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

---

使用以下方法解码文件路径

public void decodeFile(String filePath) {

// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath, o);

// The new size we want to scale to
final int REQUIRED_SIZE = 1024;

// Find the correct scale value. It should be the power of 2.
int width_tmp = o.outWidth, height_tmp = o.outHeight;

int scale = 4;
while (true) {
    if (width_tmp < REQUIRED_SIZE && height_tmp < REQUIRED_SIZE)
        break;
    width_tmp /= 2;
    height_tmp /= 2;
    scale *= 2;
}

BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
bmp = BitmapFactory.decodeFile(filePath, o2); // this bmp object of Bitmap is global and you can set it to your ImageView.
}

---

你有什么错误吗？您是否添加了清单文件的权限？您需要在图像集之前将图像转换为位图。如果您只关心将图像设置为imageView，请按Uri设置imageView，如此imageView.setImageUri（图像）；不我无法得到任何错误。您是否添加了写入和读取外部存储的权限？已经这样做了。。这就是它在emulator上运行良好的原因。我不知道为什么无法加载图片phone@dipali那你呢？？？@PiyushGupta heiyyee它起作用了。。。谢谢但我可以知道为什么我以前的代码在emulator上工作，而不是在设备上吗？在设备中，映像可能以MB为单位。在某种程度上，我们可以说，也有从相机捕获的图像，所以它将以MB为单位。所以基本上它不能被简单地解码。为此，我们必须使用这个。

public void decodeFile(String filePath) {

// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath, o);

// The new size we want to scale to
final int REQUIRED_SIZE = 1024;

// Find the correct scale value. It should be the power of 2.
int width_tmp = o.outWidth, height_tmp = o.outHeight;

int scale = 4;
while (true) {
    if (width_tmp < REQUIRED_SIZE && height_tmp < REQUIRED_SIZE)
        break;
    width_tmp /= 2;
    height_tmp /= 2;
    scale *= 2;
}

BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
bmp = BitmapFactory.decodeFile(filePath, o2); // this bmp object of Bitmap is global and you can set it to your ImageView.
}

 String path= cursor.getString(column);
 decodeFile(path);