Pass ImageView from one activity to another - Inte

问题:

I have 170 images in the drawable folder in my android app. I have one activity displaying all of them. What is want to do is to pass the clicked imageview to another activity (Zoom_activity) where the user can zoom it and play around with it. How do I achieve it?

All the images are 500x500px. So I can't think of decoding them into Bitmaps and passing Btmaps via Intent. Please suggest a better and simple way to do it! I have already had a look at the other answers here on SO but none of them solved my problem.

Here is my code:

Activity_1.java

Intent startzoomactivity = new Intent(Activity_one.this, Zoom_Image.class);
String img_name = name.getText().toString().toLowerCase(); //name is a textview which is in refrence to the imageview.
startzoomactivity.putExtra("getimage", img_name);
startActivity(startzoomactivity);

Zoom_Activity.java

    Intent startzoomactivity = getIntent();
    String img_res = getIntent().getStringExtra("getimage");
    String img_fin = "R.drawable."+img_res;
    img.setImageResource(Integer.parseInt(img_fin));

Error: App force closes

Please help me solve this problem!
Thanks!

回答1:

Integer.parseInt() only works for strings like "1" or "123" that really contain just the string representation of an Integer.

What you need is find a drawable resource by its name.

This can be done using reflection:

String name = "image_0";
final Field field = R.drawable.getField(name);
int id = field.getInt(null);
Drawable drawable = getResources().getDrawable(id);

Or using Resources.getIdentifier():

String name = "image_0";
int id = getResources().getIdentifier(name, "drawable", getPackageName());
Drawable drawable = getResources().getDrawable(id);

回答2:

What you are trying is wrong. You can not convert "R.drawable.name" with Integer.parseInt. Integer.parseInt is expecting something like "100". You should use

getIdentifier(img_fin, "drawable", getPackageName()); 

to retrieve the resources id you are looking for

回答3:

Use getResources().getIdentifier to load image from Drawable in ImageView as:

int img_id = getResources().getIdentifier(img_res, "drawable", getPackageName());
img.setImageResource(img_id);