我需要只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);

我在可绘制文件夹中有图像img1。我想展示文件中的图像。

我该怎么做呢?


当前回答

你可以使用:

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

其他回答

使用位图可以很容易地做到这一点。你可以在下面找到代码:

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

Bitmap bitMapImage= BitmapFactory.decodeFile("write path of your image");

imageView.setImageBitmap(bitMapImage);

来自官方网站: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();
}

方法如下:

    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);
    }   

我想你可以用这个

Bitmap bmImg = BitmapFactory.decodeFile("path of your img1");
imageView.setImageBitmap(bmImg);

Labeeb是对的,为什么你需要设置图像使用路径,如果你的资源已经放在资源文件夹,

只有当图像存储在SD-Card中时,才需要这种路径。

尝试下面的代码来设置存储在sd卡中的文件中的位图图像。

File imgFile = new  File("/sdcard/Images/test_image.jpg");

if(imgFile.exists()){

    Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());

    ImageView myImage = (ImageView) findViewById(R.id.imageviewTest);

    myImage.setImageBitmap(myBitmap);

}

并将此权限包含在manifest文件中:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

你还可以使用:



    File imgFile = new  File(“filepath”);
    if(imgFile.exists())
    {
        ImageView myImage = new ImageView(this);
        myImage.setImageURI(Uri.fromFile(imgFile));

    }

这为您隐式地完成位图解码。