Changing ImageView source

问题

I have an ImageView with a source image set in the xml using the following syntax:

   <ImageView 
      android:id=\"@+id/articleImg\"
      style=\"@style/articleImgSmall_2\"
      android:src=\"@drawable/default_m\" />

Now I need to change this image programmatically. What I need to do is delete the old image and add a new one though. What I have done is this:

myImgView.setBackgroundResource(R.drawable.monkey);

It works but I noticed android stacks the new image on top of the old one (dont ask me how I found out it\'s not relevant for the discussion :). I definitely need to get rid of the old one before setting the new image.

How can I achieve that?

回答1:

Changing ImageView source:

Using setBackgroundResource() method:

  myImgView.setBackgroundResource(R.drawable.monkey);

you are putting that monkey in the background.

I suggest the use of setImageResource() method:

  myImgView.setImageResource(R.drawable.monkey);

or with setImageDrawable() method:

myImgView.setImageDrawable(getResources().getDrawable(R.drawable.monkey));

*** With new android API 22 `getResources().getDrawable()` is now deprecated. This is an example how to use now:

myImgView.setImageDrawable(getResources().getDrawable(R.drawable.monkey, getApplicationContext().getTheme()));

and how to validate for old API versions:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
     myImgView.setImageDrawable(getResources().getDrawable(R.drawable.monkey, getApplicationContext().getTheme()));
   } else {
     myImgView.setImageDrawable(getResources().getDrawable(R.drawable.monkey));
}

回答2:

You're supposed to use setImageResource instead of setBackgroundResource.

回答3:

myImgView.setImageResource(R.drawable.monkey);

is used for setting image in the current image view, but if want to delete this image then you can use this code like:

((ImageView) v.findViewById(R.id.ImageView1)).setImageResource(0);

now this will delete the image from your image view, because it has set the resources value to zero.

回答4:

get ID of ImageView as

ImageView imgFp = (ImageView) findViewById(R.id.imgFp);

then Use

imgFp.setImageResource(R.drawable.fpscan);

to set source image programatically instead from XML.

回答5:

Or try this one. For me it's working fine:

imageView.setImageDrawable(ContextCompat.getDrawable(this, image));

回答6:

If you want to set in imageview an image that is inside the mipmap dirs you can do it like this:

myImageView.setImageDrawable(getResources().getDrawable(R.mipmap.my_picture)

回答7:

Supplemental visual answer

ImageView: setImageResource() (standard method, aspect ratio is kept)

View: setBackgroundResource() (image is stretched)

Both

My fuller answer is here.

回答8:

Just write a method for changing imageview

public void setImage(final Context mContext, final ImageView imageView, int picture)
{
    if (mContext != null && imageView != null)
    {
        try
        {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
            {
                imageView.setImageDrawable(mContext.getResources().getDrawable(picture, mContext.getApplicationContext().getTheme()));
            } else
            {
                imageView.setImageDrawable(mContext.getResources().getDrawable(picture));
            }
        } catch (Exception e)
        {
            e.printStackTrace();
        }
    }
}

来源：https://stackoverflow.com/questions/2974862/changing-imageview-source

标签

android

imageview

android-imageview