调用手机内存图片

        bd1 =(ImageView) findViewById ( R.id.imageView4);
      bd1.setOnClickListener ( new View.OnClickListener () {
          @Override
          public void onClick ( View v ) {
              Intent gallery = new Intent();
              gallery.setType ( "image/*" );
              gallery.setAction ( Intent.ACTION_GET_CONTENT );
              startActivityForResult ( Intent.createChooser ( gallery,"select picture" ),pick_image );
          }
      } );

一个intent的先传回去
要定义intent的类型和 intent 的action。

@Override
    protected void onActivityResult ( int requestCode, int resultCode, @Nullable Intent data ) {
        super.onActivityResult ( requestCode, resultCode, data );
        if(requestCode ==pick_image && resultCode==RESULT_OK){
           imageUri = data.getData ();

           try {Bitmap bitmap = MediaStore.Images.Media.getBitmap(getAContentResolver (),imageUri  );

               bd1.setImageBitmap ( bitmap );
           }  catch ( IOException e ) {
               e.printStackTrace ();
           }
        }
   }
}

onActivityResult 是指不写下一个activity仍然可以把结果拿回来。
通过intent getdata（）来得到uri 即图片的路径。通过路径创建bitmap