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。

1     public void setImageURI(Uri uri) { 2         if (mResource != 0 || 3                 (mUri != uri && 4                  (uri == null || mUri == null || !uri.equals(mUri)))) { 5             updateDrawable(null); 6             mResource = 0; 7             mUri = uri; 8  9             final int oldWidth = mDrawableWidth;10             final int oldHeight = mDrawableHeight;11 12             resolveUri();13 14             if (oldWidth != mDrawableWidth || oldHeight != mDrawableHeight) {15                 requestLayout();16             }17             invalidate();18         }19     }

 

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

1 Bitmap bmp;2 try {3     bmp = MediaStore.Images.Media.getBitmap(context.getContentResolver(), Uri.fromFile(file));4     iv.setImageBitmap(bmp); 5 } catch (FileNotFoundException e) {6 } catch (IOException e) {7 }

NetWorkImageView

//Copy the code from Volley's NetworkImageView and change onLayout as below.@Overrideprotected 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...@Overridepublic void setImageDrawable(Drawable drawable) {    mUrl = null;    super.setImageDrawable(drawable);}@Overridepublic void setImageURI(Uri uri) {    mUrl = null;    super.setImageURI(uri);}

 

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