ImageView setImageURI图片不改变\NetWorkImageView 不显示的问题

ImageView

问题描述：图片文件已改变，第二次调用ImageView.setImageURI时无法更新图片

分析：setImageURI方法中对uri进行了缓存，由于第一次加载过了该uri的资源，即使该文件内容改变了，判断中仍然会使用之前加载的。

     public void setImageURI(Uri uri) {
         if (mResource != 0 ||
                 (mUri != uri &&
                  (uri == null || mUri == null || !uri.equals(mUri)))) {
             updateDrawable(null);
             mResource = 0;
             mUri = uri;

             final int oldWidth = mDrawableWidth;
             final int oldHeight = mDrawableHeight;

             resolveUri();

             if (oldWidth != mDrawableWidth || oldHeight != mDrawableHeight) {
                 requestLayout();
             }
             invalidate();
         }
     }

解决办法：

1、使用不同的文件名（不同的URI）

2、使用setImageBitmap的方式代替

 Bitmap bmp;
 try {
     bmp = MediaStore.Images.Media.getBitmap(context.getContentResolver(), Uri.fromFile(file));
     iv.setImageBitmap(bmp);
 } catch (FileNotFoundException e) {
 } catch (IOException e) {
 }

NetWorkImageView

//Copy the code from Volley's NetworkImageView and change onLayout as below.

@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
    super.onLayout(changed, left, top, right, bottom);
    if (!TextUtils.isEmpty(mUrl)) {
        loadImageIfNecessary(true);
    }else{
        if (mImageContainer != null) {
            mImageContainer.cancelRequest();
            mImageContainer = null;
        }
    }
}

//Change the other ImageView image setters, for example...
@Override
public void setImageDrawable(Drawable drawable) {
    mUrl = null;
    super.setImageDrawable(drawable);
}

@Override
public void setImageURI(Uri uri) {
    mUrl = null;
    super.setImageURI(uri);
}    

Reference:http://kalkanotel.com/networkimageview-set-image-from-file-i225690.htm