java - 如何使用片段在 viewpager 中打开 sd 卡中的多个图像？
问题描述
我是 android 新手，我正在制作一个应用程序，它可以从图库中选择和打开多个图像，并且可以作为幻灯片查看。然后使用画布在图像上绘制并记录整个屏幕。
除了将画廊中的多张图片加载到我的应用程序之外，我已经完成了所有的工作。
我可以从可绘制的图像中打开图像，但很难从图库中打开。
我正在使用ViewPager和片段从可绘制对象中打开图像，请让我知道一种从图库中打开多个图像并显示在我的ViewPager.
页面片段类
package com.example.test2;
public class PageFragment extends Fragment {
private int imageResource;
private Bitmap bitmap;
public static PageFragment getInstance(int resourceID) {
PageFragment f = new PageFragment();
Bundle args = new Bundle();
args.putInt("image_source", resourceID);
f.setArguments(args);
return f;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
imageResource = getArguments().getInt("image_source");
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_page, container, false);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
ImageView imageView = (ImageView) view.findViewById(R.id.image);
BitmapFactory.Options o = new BitmapFactory.Options();
o.inSampleSize = 4;
o.inDither = false;
bitmap = BitmapFactory.decodeResource(getResources(), imageResource, o);
imageView.setImageBitmap(bitmap);
}
@Override
public void onDestroy() {
super.onDestroy();
bitmap.recycle();
bitmap = null;
}
}
viewPagerAdapter 类
package com.example.test2;
public class ViewPagerAdapter extends FragmentStatePagerAdapter {
private List<Integer> images;
public ViewPagerAdapter(FragmentManager fm, List<Integer> imagesList) {
super(fm);
this.images = imagesList;
}
@Override
public Fragment getItem(int position) {
return PageFragment.getInstance(images.get(position));
}
@Override
public int getCount() {
return images.size();
}
}
主要活动
package com.example.test2;
public class MainActivity extends AppCompatActivity {
ImageButton draw;
RelativeLayout relativeLayout;
Paint paint;
View view;
Path path2;
Bitmap bitmap;
Canvas canvas;
private ArrayList<Integer> images;
private BitmapFactory.Options options;
private ViewPager viewPager;
private View btnNext, btnPrev;
private FragmentStatePagerAdapter adapter;
private LinearLayout thumbnailsContainer;
private final static Integer[] resourceIDs = new Integer[]{R.mipmap.image7,R.mipmap.image6,R.mipmap.image5
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
images = new ArrayList<>();
//find view by id
viewPager = (ViewPager) findViewById(R.id.view_pager);
thumbnailsContainer = (LinearLayout) findViewById(R.id.container);
btnNext = findViewById(R.id.next);
btnPrev = findViewById(R.id.prev);
btnPrev.setOnClickListener(onClickListener(0));
btnNext.setOnClickListener(onClickListener(1));
setImagesData();
// init viewpager adapter and attach
adapter = new ViewPagerAdapter(getSupportFragmentManager(), images);
viewPager.setAdapter(adapter);
inflateThumbnails();
relativeLayout = (RelativeLayout) findViewById(R.id.layout);
draw= findViewById(R.id.b);
draw.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final Dialog dialog = new Dialog(MainActivity.this);
dialog.setTitle("");
dialog.setContentView(R.layout.menu);
dialog.show();
Button black = dialog.findViewById(R.id.Black);
Button blue = dialog.findViewById(R.id.Blue);
Button red = dialog.findViewById(R.id.Red);
black.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
color();
paint.setColor(Color.parseColor("black"));
dialog.dismiss();
}
});
blue.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
color();
paint.setColor(Color.parseColor("blue"));
dialog.dismiss();
}
});
red.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
color();
paint.setColor(Color.parseColor("red"));
dialog.dismiss();
}
});
}
});
}
private View.OnClickListener onClickListener(final int i) {
return new View.OnClickListener() {
@Override
public void onClick(View v) {
if (i > 0) {
//next page
if (viewPager.getCurrentItem() < viewPager.getAdapter().getCount() - 1) {
viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);
}
} else {
//previous page
if (viewPager.getCurrentItem() > 0) {
viewPager.setCurrentItem(viewPager.getCurrentItem() - 1);
}
}
}
};
}
private void setImagesData() {
for (int i = 0; i < resourceIDs.length; i++) {
images.add(resourceIDs[i]);
}
}
private void inflateThumbnails() {
for (int i = 0; i < images.size(); i++) {
View imageLayout = getLayoutInflater().inflate(R.layout.item_image, null);
ImageView imageView = (ImageView) imageLayout.findViewById(R.id.img_thumb);
imageView.setOnClickListener(onChagePageClickListener(i));
options = new BitmapFactory.Options();
options.inSampleSize = 3;
options.inDither = false;
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),images.get(i),options);
imageView.setImageBitmap(bitmap);
//set to image view
imageView.setImageBitmap(bitmap);
//add imageview
thumbnailsContainer.addView(imageLayout);
}
}
private View.OnClickListener onChagePageClickListener(final int i) {
return new View.OnClickListener() {
@Override
public void onClick(View v) {
viewPager.setCurrentItem(i);
}
};
}
public void color()
{
view = new SketchSheetView(MainActivity.this);
paint = new Paint();
path2 = new Path();
relativeLayout.addView(view, new ViewGroup.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT,
RelativeLayout.LayoutParams.MATCH_PARENT));
paint.setDither(true);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeCap(Paint.Cap.ROUND);
paint.setStrokeWidth(6);
}
class SketchSheetView extends View {
public SketchSheetView(Context context) {
super(context);
bitmap = Bitmap.createBitmap(820, 480, Bitmap.Config.ARGB_4444);
canvas = new Canvas(bitmap);
this.setBackgroundColor(Color.TRANSPARENT);
}
private ArrayList<DrawingClass> DrawingClassArrayList = new ArrayList<DrawingClass>();
@Override
public boolean onTouchEvent(MotionEvent event) {
DrawingClass pathWithPaint = new DrawingClass();
canvas.drawPath(path2, paint);
if (event.getAction() == MotionEvent.ACTION_DOWN) {
path2.moveTo(event.getX(), event.getY());
path2.lineTo(event.getX(), event.getY());
}
else if (event.getAction() == MotionEvent.ACTION_MOVE) {
path2.lineTo(event.getX(), event.getY());
pathWithPaint.setPath(path2);
pathWithPaint.setPaint(paint);
DrawingClassArrayList.add(pathWithPaint);
}
invalidate();
return true;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (DrawingClassArrayList.size() > 0) {
canvas.drawPath(
DrawingClassArrayList.get(DrawingClassArrayList.size() - 1).getPath(),
DrawingClassArrayList.get(DrawingClassArrayList.size() - 1).getPaint());
}
}
}
public class DrawingClass {
Path DrawingClassPath;
Paint DrawingClassPaint;
private Path getPath() {
return DrawingClassPath;
}
private void setPath(Path path) {
this.DrawingClassPath = path;
}
private Paint getPaint() {
return DrawingClassPaint;
}
private void setPaint(Paint paint) {
this.DrawingClassPaint = paint;
}
}
}
解决方案
我不确定是否可以直接到达画廊，您需要调用意图。
我建议你启动一个方法来检索画廊中的照片，按照这个例子：在此处输入链接描述，将所有图像保存到一个列表中，并像你已经完成的那样在 viewpager 中显示图片。
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