Update app.py

fix examples bug

app.py

@@ -1136,9 +1136,9 @@ with gr.Blocks(theme=gr.themes.Default()) as demo:
                                     'For interactive segmentation:<br />\
                                         1.Draw points, boxes, or scribbles on the canvas for multiclass segmentation; use separate layers for different objects, adding layers with a "+" sign.<br />\
                                         2.Point mode accepts a single point only; multiple points default to the centroid, so use boxes or scribbles for larger objects.<br />\
-                                        3.After drawing, click green "√" to preview the prompt visualization; the segmentation mask follows the chosen prompt colors.'
+                                        3.After drawing, you can click "preview" button to preview the prompt visualization, but need redraw it again for segmentation; the segmentation mask follows the chosen prompt colors.'
                                     )
-
+                            image_preview_button = gr.Button("preview & redraw")
                             img_showbox = gr.Image(label="visual prompt area preview")
 
                         
@@ -1215,7 +1215,8 @@ with gr.Blocks(theme=gr.themes.Default()) as demo:
              
        
         image_button = gr.Button("Detect & Segment")
-        img_input.change(visual_prompt_preview,  inputs = [img_input,prompt_mode_select] ,  outputs = img_showbox)
+        image_preview_button.click(visual_prompt_preview,  inputs = [img_input,prompt_mode_select] ,  outputs = img_showbox)
+        # img_input.change(visual_prompt_preview,  inputs = [img_input,prompt_mode_select] ,  outputs = img_showbox)
         image_button.click(segment_image, inputs=[img_input, prompt_mode_select, category_select, custom_category,input_expressiong, results_select, num_inst_select, threshold_select, mask_image_mix_ration,model_select], outputs=image_segment)
         gr.Examples(
             examples = image_example_list,