Android 如何从资源加载图像?
我需要从资产中加载一个图像,以避免在某些特定情况下,froyo 2.2.2错误调整POT图像的大小。避免这种情况的方法是从assets dir加载图像文件 我正试图做到这一点:Android 如何从资源加载图像?,android,assets,Android,Assets,我需要从资产中加载一个图像,以避免在某些特定情况下,froyo 2.2.2错误调整POT图像的大小。避免这种情况的方法是从assets dir加载图像文件 我正试图做到这一点: String imagePath = "radiocd5.png"; AssetManager mngr = context.getAssets(); // Create an input stream to read from the asset folder InputStream is = nu
String imagePath = "radiocd5.png";
AssetManager mngr = context.getAssets();
// Create an input stream to read from the asset folder
InputStream is = null;
try {
is = mngr.open(imagePath);
} catch (IOException e1) { e1.printStackTrace();}
//Get the texture from the Android resource directory
//InputStream is = context.getResources().openRawResource(R.drawable.radiocd5);
Bitmap bitmap = null;
try {
//BitmapFactory is an Android graphics utility for images
bitmap = BitmapFactory.decodeStream(is);
} finally {
//Always clear and close
try {
is.close();
is = null;
} catch (IOException e) {}
}
但是我在is.close()行上得到了NullPointerException代码>
我捕获了一个FileNotFoundException:radiocd5.png,但该文件位于我的资产目录:S中
我做了什么坏事?该文件名为radiocd5.png
,位于assets
目录下,而不是使用assets目录,将该文件放入/res/raw,然后您可以使用以下URI访问它:android。resource://com.your.packagename/“+R.raw.radiocd5
您可以按照我的教程中的说明显示资产中的数据:
加载要显示的图像和文本的示例
我现在添加了所提供链接的相关部分
(在地震或其他情况下);-)泰芬
另一个版本,在片段中:
@Override
public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{ root = inflater.inflate(R.layout.createrestaurant_layout, container, false);
Resources res = getResources();
img = (ImageView) root.findViewById(R.id.img);
AssetManager amanager = res.getAssets();
try {
InputStream imageStream = amanager.open("restaurant.jpg");
Drawable drawable = new BitmapDrawable(res, imageStream);
img.setImageDrawable(drawable);
} catch (Exception e) { e.printStackTrace(); }
}
在iOS/UIKit或iOS/SwiftUI中,此过程似乎要简单得多。这里是另一种方法
setImageBitmap(BitmapFactory.decodeStream(assets.open("photo.jpg")))
我没有原始目录,我无法创建它,因为此应用程序将由我们公司的生成器自动生成,无法创建目录。什么错误?请澄清,只要您提供足够好的信息,我会尽力帮助您。我捕获了一个文件NotFoundException:radiocd5.png,但该文件位于我的资产目录:Sa good practice,无论何时更新资源,清理项目并再次运行!图像加载后,输入流不也应该关闭吗?在第50行之后。你能在你的回答中提供一些代码和说明吗。链接回答是不鼓励的,尤其是其他网站可能会宕机(earthqake或一些你永远不知道的东西:P)
protected String openImageInAssets(String imageName){
String encodedImageBase64 = "";
AssetManager assetManager = getAssets();
InputStream fileStream = null;
try {
fileStream = assetManager.open(imageName);
if(fileStream != null){
// BitmapFactory.Options bfo = new BitmapFactory.Options();
// bfo.inPreferredConfig = Bitmap.Config.ARGB_8888;
// Bitmap bitmap = BitmapFactory.decodeStream(fileStream, null, bfo);
Bitmap bitmap = BitmapFactory.decodeStream(fileStream);
// Convert bitmap to Base64 encoded image for web
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
// to get image extension file name split the received
int fileExtensionPosition = imageName.lastIndexOf('.');
String fileExtension = imageName.substring(fileExtensionPosition+1);
// Log.d(IConstants.TAG,"fileExtension: " + fileExtension);
if(fileExtension.equalsIgnoreCase("png")){
bitmap.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream);
// Log.d(IConstants.TAG,"fileExtension is PNG");
}else if(fileExtension.equalsIgnoreCase("jpg") || fileExtension.equalsIgnoreCase("jpeg")){
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream);
// Log.d(TAG,"fileExtension is JPG");
}
byte[] byteArray = byteArrayOutputStream.toByteArray();
String imgageBase64 = Base64.encodeToString(byteArray, Base64.DEFAULT);
encodedImageBase64 = "data:image/png;base64," + imgageBase64;
}
} catch (IOException e) {
e.printStackTrace();
return encodedImageBase64="";
}
finally {
//Always clear and close
try {
if(fileStream != null) {
fileStream.close();
fileStream = null;
}
} catch (IOException e) {
e.printStackTrace();
}
}
// Log.d(TAG,"encodedImageBase64: " + encodedImageBase64);
return encodedImageBase64;
}
@Override
public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{ root = inflater.inflate(R.layout.createrestaurant_layout, container, false);
Resources res = getResources();
img = (ImageView) root.findViewById(R.id.img);
AssetManager amanager = res.getAssets();
try {
InputStream imageStream = amanager.open("restaurant.jpg");
Drawable drawable = new BitmapDrawable(res, imageStream);
img.setImageDrawable(drawable);
} catch (Exception e) { e.printStackTrace(); }
}
setImageBitmap(BitmapFactory.decodeStream(assets.open("photo.jpg")))