从文件路径显示图像视图？

我不是女神ヾ 2022-11-28 10:54 81阅读 0赞

本文翻译自：[Show Image View from file path?][Show Image View from file path]

*I need to show an image by using the file name only, not from the resource id.* **我需要仅使用文件名来显示图像，而不是使用资源ID。**

ImageView imgView = new ImageView(this);
    imgView.setBackgroundResource(R.drawable.img1);

*I have the image img1 in the drawable folder.* **我在drawable文件夹中有图像img1。** *I wish to show that image from the file.* **我希望从文件中显示该图像。**

*How can I do this?* **我怎样才能做到这一点？**

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### \#1楼 ###

参考：[https://stackoom.com/question/hxRY/从文件路径显示图像视图][https_stackoom.com_question_hxRY]

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### \#2楼 ###

*You can use:* **您可以使用：**

ImageView imgView = new ImageView(this);
    InputStream is = getClass().getResourceAsStream("/drawable/" + fileName);
    imgView.setImageDrawable(Drawable.createFromStream(is, ""));

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### \#3楼 ###

mageView.setImageResource(R.id.img);

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### \#4楼 ###

public static Bitmap decodeFile(String path) {
        Bitmap b = null;
        File f = new File(path);
        // Decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
    
        FileInputStream fis = null;
        try {
            fis = new FileInputStream(f);
            BitmapFactory.decodeStream(fis, null, o);
            fis.close();
    
            int IMAGE_MAX_SIZE = 1024; // maximum dimension limit
            int scale = 1;
            if (o.outHeight > IMAGE_MAX_SIZE || o.outWidth > IMAGE_MAX_SIZE) {
                scale = (int) Math.pow(2, (int) Math.round(Math.log(IMAGE_MAX_SIZE / (double) Math.max(o.outHeight, o.outWidth)) / Math.log(0.5)));
            }
    
            // Decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
    
            fis = new FileInputStream(f);
            b = BitmapFactory.decodeStream(fis, null, o2);
            fis.close();
    
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    
        return b;
    }
    
    public static Bitmap showBitmapFromFile(String file_path)
    {
        try {
            File imgFile = new  File(file_path);
            if(imgFile.exists()){
    
                Bitmap pic_Bitmap = decodeFile(file_path);
                return pic_Bitmap;
    
            }
        } catch (Exception e) {
            MyLog.e("Exception showBitmapFromFile");
            return null;
        }
        return null;
    }

*if you are using image loading in List view then use Aquery concept .* **如果您在列表视图中使用图像加载，则使用Aquery概念。**

*[https://github.com/AshishPsaini/AqueryExample][https_github.com_AshishPsaini_AqueryExample]* **[https://github.com/AshishPsaini/AqueryExample][https_github.com_AshishPsaini_AqueryExample]**

AQuery  aq= new AQuery((Activity) activity, convertView);
                //load image from file, down sample to target width of 250 pixels .gi 
        File file=new File("//pic/path/here/aaaa.jpg");
        if(aq!=null)
        aq.id(holder.pic_imageview).image(file, 250);

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### \#5楼 ###

*All the answers are outdated.* **所有答案都已过时。** *It is best to use [picasso][] for such purposes.* **最好将[毕加索][picasso]用于此类目的。** *It has a lot of features including background image processing.* **它有很多功能，包括背景图像处理。**

*Did I mention it is super easy to use:* **我提到它非常容易使用：**

Picasso.with(context).load(new File(...)).into(imageView);

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### \#6楼 ###

*From the official site: [http://developer.android.com/training/displaying-bitmaps/load-bitmap.html][http_developer.android.com_training_displaying-bitmaps_load-bitmap.html]* **从官方网站： [http][http_developer.android.com_training_displaying-bitmaps_load-bitmap.html] ： [//developer.android.com/training/displaying-bitmaps/load-bitmap.html][http_developer.android.com_training_displaying-bitmaps_load-bitmap.html]**

ImageView image = (ImageView) findViewById(R.id.imagePreview);           
    try {
        image.setImageBitmap(decodeSampledBitmap(picFilename));
    } catch (Exception e) {
        e.printStackTrace();
    }

*Here the methods:* **这里的方法：**

private int calculateInSampleSize(
                BitmapFactory.Options options, int reqWidth, int reqHeight) {
            // Raw height and width of image
            final int height = options.outHeight;
            final int width = options.outWidth;
            int inSampleSize = 1;
    
            if (height > reqHeight || width > reqWidth) {
    
                final int halfHeight = height / 2;
                final int halfWidth = width / 2;
    
                // Calculate the largest inSampleSize value that is a power of 2 and keeps both
                // height and width larger than the requested height and width.
                while ((halfHeight / inSampleSize) > reqHeight
                        && (halfWidth / inSampleSize) > reqWidth) {
                    inSampleSize *= 2;
                }
            }
    
            return inSampleSize;
        }
    
        private Bitmap decodeSampledBitmap(String pathName,
                int reqWidth, int reqHeight) {
    
            // First decode with inJustDecodeBounds=true to check dimensions
            final BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(pathName, options);
    
            // Calculate inSampleSize
            options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
    
            // Decode bitmap with inSampleSize set
            options.inJustDecodeBounds = false;
            return BitmapFactory.decodeFile(pathName, options);
        }
    
    //I added this to have a good approximation of the screen size: 
        private Bitmap decodeSampledBitmap(String pathName) {
            Display display = getWindowManager().getDefaultDisplay();
            Point size = new Point();
            display.getSize(size);
            int width = size.x;
            int height = size.y;
            return decodeSampledBitmap(pathName, width, height);
        }

[Show Image View from file path]: https://oldbug.net/q/hxRY/Show-Image-View-from-file-path
[https_stackoom.com_question_hxRY]: https://stackoom.com/question/hxRY/%E4%BB%8E%E6%96%87%E4%BB%B6%E8%B7%AF%E5%BE%84%E6%98%BE%E7%A4%BA%E5%9B%BE%E5%83%8F%E8%A7%86%E5%9B%BE
[https_github.com_AshishPsaini_AqueryExample]: https://github.com/AshishPsaini/AqueryExample
[picasso]: http://square.github.io/picasso/
[http_developer.android.com_training_displaying-bitmaps_load-bitmap.html]: http://developer.android.com/training/displaying-bitmaps/load-bitmap.html