Question

在我的Android应用程序中，我正在从设备库中检索图像并将其设置为新活动的背景。

从图库中检索图片的代码：

 btn_select.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent();
            intent.setType("image/*");
            intent.setAction(Intent.ACTION_GET_CONTENT);
            startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);
        }
    });

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == requestCode && resultCode == RESULT_OK && null != data) {
        Uri selectedImage = data.getData();
        String[] filePathColumn = { MediaStore.Images.Media.DATA };

        Cursor cursor = getContentResolver().query(selectedImage,
                filePathColumn, null, null, null);
        cursor.moveToFirst();

        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        String picturePath = cursor.getString(columnIndex);
        Intent i=new Intent(getApplicationContext(),DisplayActivity.class);
        Bundle bundle=new Bundle();
        bundle.putString("path",picturePath);
        i.putExtras(bundle);
        startActivity(i);
        cursor.close();

    }
}

然后在新活动中设置为背景：

<?xml version="1.0" encoding="utf-8"?>
    <FrameLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <ImageView
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:id="@+id/dis_img"
            android:adjustViewBounds="true"
            />

    </FrameLayout>


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

    dis_img.setImageURI(Uri.parse(path_image);

但是在运行应用程序时，imageview显示在活动的中间，而不是显示为背景图像。

请帮我设置此图片作为活动的背景。

Answer 1

dis_image.setBackgroundResourse(path_image)

如果dis_image视图与照片意图在同一个活动中，这将把图像设置为背景，如果你想将uri带到不同的活动并在那里设置背景，你可以简单地通过意图传递uri 如

Intent i=new Intent(thisActivity.this,Nextactivity.class);i.putExtra("imageUri",path_image.toString());startActivity(i)

然后

   Intent intent = getIntent();Uri uri = Uri.parse(intent.getStringExtra("id");dis_image.setBackgroundResourse(uri)

然后下一个活动你可以简单地从意图中检索这个uri路径并如上所示进行设置。确保您首先拥有以下权限

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

确保将此图片视图设置为ur layout

中的背景视图

如果您无法找到更好的方法，请尝试这种方法

＆＃13;

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"> 
<ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent" 
        android:id="@+id/imageView"/>
        
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/transparent">
        
        //Now i design all my layout here
        
    </LinearLayout>
</RelativeLayout>

＆＃13;

现在开始活动，我首先从意图中获取uri然后

imageView.setImageUri(Uri)

Answer 2

我这样做的方式是：

图片浏览：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    ...
    >

    <ImageView
        android:id="@+id/backdrop"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:adjustViewBounds="true"
        android:contentDescription="@string/background_image"
        android:scaleType="centerCrop" />

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.google.android.gms.ads.AdView
            ...
        />

        <android.support.v7.widget.RecyclerView
            ...
        />
    </RelativeLayout>

    <ProgressBar
        ...
    />

    <com.flipkart.chatheads.ui.ChatHeadContainer
        ...
    />
</FrameLayout>

在Activity类中：

ImageView backdropView = (ImageView) findViewById(R.id.backdrop);
assert backdropView != null;
backdropView.setImageBitmap(HelperMethods.getBitmapFromUri(uri, this));

助手班级：

/**
 * This method returns bitmap for a specified URI
 *
 * @param uri  URI of image to be converted to bitmap
 * @param mAct Context of activity
 * @return Bitmap
 */

public static Bitmap getBitmapFromUri(Uri uri, Activity mAct) {

    InputStream in;
    try {
        final int IMAGE_MAX_SIZE = 800000; // 0.8MP
        in = mAct.getContentResolver().openInputStream(uri);

        // Decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(in, null, o);
        in.close();

        int scale = 1;
        while ((o.outWidth * o.outHeight) * (1 / Math.pow(scale, 2)) >
                IMAGE_MAX_SIZE) {
            scale++;
        }

        Bitmap b;
        in = mAct.getContentResolver().openInputStream(uri);
        if (scale > 1) {
            scale--;
            // scale to max possible inSampleSize that still yields an image
            // larger than target
            o = new BitmapFactory.Options();
            o.inSampleSize = scale;
            b = BitmapFactory.decodeStream(in, null, o);

            // resize to desired dimensions
            int height = b.getHeight();
            int width = b.getWidth();
            double y = Math.sqrt(IMAGE_MAX_SIZE
                    / (((double) width) / height));
            double x = (y / height) * width;

            Bitmap scaledBitmap = Bitmap.createScaledBitmap(b, (int) x,
                    (int) y, true);
            b.recycle();
            b = scaledBitmap;

            System.gc();
        } else {
            b = BitmapFactory.decodeStream(in);
        }
        in.close();
        return b;
    } catch (IOException e) {
        return null;
    }
}

可能不是最好的方法，但它对我有用:) get getBitmapFromUri（）方法将缩小实际的位图，以便你不会出现内存异常！

将Imageview设置为android中的背景时出现问题

2 个答案: