Eyedropper Tool does not working for Halftone

Either hold down the Shift key when using the Eyedropper or double click the Eyedropper tool in the Toolbar and uncheck: Eyedropper Picks Up > Appearance.

@Imran329760181i5n You are correct. Illustrator Eyedropper Tool doesn't work directly on Halftone or Bitmap images because these image types are fundamentally different from vector graphics, which Illustrator primarily deals with. Halftone and bitmap images are made up of a grid of individual pixels, each containing color information. 

There are a few work-arounds:

1. Hold down the Shift key while clicking on the halftone/bitmap image with the Eyedropper Tool. This would tell Illustrator to ignore the object's appearance attributes (which are essentially none for a raster image) and instead pick up the RGB color value of the pixel you click on. This color will then be applied to the currently selected vector object's active fill or stroke. OR
   
   
2. Try using the Object > Create Object Mosaic feature on the halftone/bitmap image. This will convert the image into a grid of individual colored tiles that approximate the original image's appearance. OR

Enter the 'Tiling Spacing,'

Once converted, you can use the Eyedropper Tool to sample the color of any of these individual tiles, effectively picking up the "colors" that make up the halftone or bitmap pattern. Keep in mind that this process rasterizes the image into many individual vector objects, which might significantly increase file size and alter the original image's crispness depending on the settings used for the mosaic.

3. Select the image and rasterize the image