android - 将SD卡中的图像放入android中的imageview

Question

我必须将图像从 sd 卡放置到 android 中的 imageview

我尝试使用 getExternalStorageDirectory()。它显示已弃用的方法。它不起作用。

主要 Activity

public class MainActivity extends Activity {

    ImageView imageView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageView = (ImageView)findViewById(R.id.imageView1);


        try {
            Bitmap picture = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getPath()+"/DCIM/mm.png");

            imageView.setImageBitmap(picture);
        } catch (Exception e) {
            Log.e("Error reading file", e.toString());
        }

//        File imgFile = new  File("/sdcard/DCIM/mm.png");
//
//        if(imgFile.exists()) {
//
//            Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
//
//            imageView.setImageBitmap(myBitmap);
//        }


    }

}

xml文件

<?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
    xmlns:tools = "http://schemas.android.com/tools"
    android:layout_width = "match_parent"
    android:layout_height = "match_parent"
    tools:context = ".MainActivity"
    android:orientation = "vertical">

    <ImageView
        android:id = "@+id/imageView1"
        android:layout_width = "wrap_content"
        android:layout_height = "wrap_content"
        />
</LinearLayout>

我尝试了很多方法。但它不起作用。请建议我这样做。

Answer 1

list 添加此权限:

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

在您的 Activity 中声明:

String[] PERMISSIONS = {android.Manifest.permission.WRITE_EXTERNAL_STORAGE,android.Manifest.permission.READ_EXTERNAL_STORAGE};
private Context mContext=MainActivity.this;

private static final int REQUEST = 112;
static ImageView muyimage;

在 Oncreate() 中；

muyimage=(ImageView)findViewById(R.id.myimge);
    if (Build.VERSION.SDK_INT >= 23) {
        String[] PERMISSIONS = {android.Manifest.permission.WRITE_EXTERNAL_STORAGE};
        if (!hasPermissions(mContext, PERMISSIONS)) {
            ActivityCompat.requestPermissions((Activity) mContext, PERMISSIONS, REQUEST );
        } else {
            try {
 //here i have mentioned my image path ,you have to set your image path
                Bitmap picture = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getPath()+"/Pictures/Screenshots/mine.png");

                muyimage.setImageBitmap(picture);
            } catch (Exception e) {
                Log.e("Error reading file", e.toString());
            }
        }
    } else {
        try {
 //here i have mentioned my image path ,you have to set your image path
            Bitmap picture = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getPath()+"/Pictures/Screenshots/mine.png");

            muyimage.setImageBitmap(picture);
        } catch (Exception e) {
            Log.e("Error reading file", e.toString());
        }
    }

还有这个

 @Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {
        case REQUEST: {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                //do here
            } else {
                Toast.makeText(mContext, "The app was not allowed to write in your storage", Toast.LENGTH_LONG).show();
            }
        }
    }
}
private static boolean hasPermissions(Context context, String... permissions) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && context != null && permissions != null) {
        for (String permission : permissions) {
            if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) {
                try {
 //here i have mentioned my image path ,you have to set your image path
                    Bitmap picture = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getPath()+"/Pictures/Screenshots/mine.png");

                    muyimage.setImageBitmap(picture);
                } catch (Exception e) {
                    Log.e("Error reading file", e.toString());
                }
                return false;
            }
        }
    }
    return true;
}