Android實現圖片點選放大
阿新 • • 發佈:2020-10-29
本文例項為大家分享了Android實現圖片點選放大的具體程式碼,供大家參考,具體內容如下
在我的專案中,有點選圖片banner後放大瀏覽的功能。我的做法就是建立一個專門的圖片顯示Activity,佈局裡面用ViewPage,這樣就能控制圖片的左右滑動,並且控制首先顯示第幾張圖片。
功能是ok的,顯示也是正常的。但我花費了好幾天的時間來實現、完善這個功能。
ShowMoreImageActivity
/** * 圖片放大 */ public class ShowMoreImageActivity extends BaseActivity { @FindId(R.id.vp) private ViewPager vp; @FindId(R.id.ll_point) private LinearLayout ll_point; private List<String> imgs; @FindId(R.id.btn_save) private ImageView btn_save; private int index; public static int type; private Activity activity; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_show_more_image); initViews(); activity = this; } private void initViews() { AutoFindId.findId(context); imgs = (ArrayList<String>) getIntent().getSerializableExtra("img"); index = getIntent().getIntExtra("index",0); type = getIntent().getIntExtra("type",0); vp.setAdapter(new MoreImgPagerAdapter(context,imgs)); vp.addOnPageChangeListener(new OnPageChangeListener() { @Override public void onPageSelected(int arg0) { index = arg0; setUpPoint(imgs.size(),arg0); } @Override public void onPageScrolled(int arg0,float arg1,int arg2) { } @Override public void onPageScrollStateChanged(int arg0) { } }); setUpPoint(imgs.size(),0); vp.setCurrentItem(index); } protected void downLoad(final String urls) { String[] split = urls.split("\\?"); final String url = split[0]; if (url.startsWith("file")) { G.toast(context,"此為本地圖片,不用下載,路徑為" + url.replace("file://","")); return; } if (OKHttpUtils.isNetworkAvailable(context)) { G.showPd(context); TDUtils.execute(new Runnable() { @Override public void run() { try { File file = new File(C.getDownloadPath()); if (!file.exists()) { file.mkdir(); } File jpg = new File(C.getDownloadPath() + G.urlToFileName(url)); // 如果已經存在則不需要下載 if (jpg != null && jpg.exists()) { G.dismissProgressDialogInThread(); G.toastInThread(context,"該檔案已被下載到" + jpg.getParent() + context.getResources().getString(R.string.xia)); return; } // 先從快取中查詢 File tmpFile = NetAide.getBitmapUtils().getBitmapFileFromDiskCache(url); if (tmpFile != null && tmpFile.exists()) { G.look("---從快取中查詢到圖片----"); Bitmap bm = BitmapFactory.decodeFile(tmpFile.getAbsolutePath()); FileOutputStream fos = new FileOutputStream(jpg); bm.compress(CompressFormat.JPEG,100,fos); fos.close(); G.dismissProgressDialogInThread(); // 通知相簿更新 C.noticeImageRefresh(context,jpg); G.toastInThread(context,context.getResources().getString(R.string.downLoadUrl) + jpg.getParent() + context.getResources().getString(R.string.xia)); return; } // 從網路上下載儲存 Bitmap bm = BitmapFactory.decodeStream(new URL(url).openStream()); FileOutputStream fos = new FileOutputStream(jpg); bm.compress(CompressFormat.JPEG,fos); fos.close(); G.dismissProgressDialogInThread(); // 通知相簿更新 C.noticeImageRefresh(context,jpg); G.toastInThread(context,"你現在可以在相簿中檢視該圖片了"); } catch (Exception e) { e.printStackTrace(); G.dismissProgressDialogInThread(); G.toastInThread(context,context.getResources().getString(R.string.downLoadFail)); File jpg = new File(C.getDownloadPath() + G.urlToFileName(url)); if (jpg != null && jpg.exists()) { jpg.delete(); } } } }); } } private void setUpPoint(int size,int choose) { ll_point.removeAllViews(); if (size <= 1) { return; } for (int i = 0; i < size; i++) { ImageView point = new ImageView(context); point.setLayoutParams(new LinearLayout.LayoutParams(DensityUtil.dip2px(context,15),-2)); point.setScaleType(ScaleType.FIT_CENTER); if (i == choose) { point.setImageResource(R.drawable.white_choosed); } else { point.setImageResource(R.drawable.white_no_choosed); } ll_point.addView(point); } } public void doClcik(View view) { switch (view.getId()){ case R.id.btn_save: PermissionUtils permissionUtils = new PermissionUtils(); permissionUtils.setPermission(this,"儲存","儲存圖片",new PermissionUtils.AfterPermission() { @Override public void doNext() { downLoad(imgs.get(index)); } },Manifest.permission.WRITE_EXTERNAL_STORAGE); break; } } }
對應佈局:
<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@android:color/black" android:orientation="vertical"> <androidx.viewpager.widget.ViewPager android:id="@+id/vp" android:layout_width="match_parent" android:layout_height="match_parent" /> <LinearLayout android:layout_width="match_parent" android:layout_height="40dp" android:layout_marginTop="25dp"> <LinearLayout android:layout_width="50dp" android:layout_height="match_parent" android:onClick="onFinish"> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_marginLeft="10dp" android:background="@drawable/nav_back" /> </LinearLayout> <View android:layout_width="0dp" android:layout_height="0dp" android:layout_weight="1" /> <ImageView android:id="@+id/btn_save" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_marginRight="10dp" android:onClick="doClcik" android:src="@drawable/download_img" /> </LinearLayout> <LinearLayout android:id="@+id/ll_point" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_gravity="bottom" android:layout_marginBottom="40dp" android:gravity="center" android:orientation="horizontal"/> </FrameLayout>
MoreImgPagerAdapter
public class MoreImgPagerAdapter extends PagerAdapter { private Context context; private List<String> images; private SparseArray<SoftReference<View>> ivs; public MoreImgPagerAdapter(Context context,List<String> images) { this.context = context; this.images = images; ivs = new SparseArray<SoftReference<View>>(); } @Override public int getCount() { return images.size(); } @Override public void destroyItem(ViewGroup arg0,int arg1,Object arg2) { SoftReference<View> reference = ivs.get(arg1); if (reference != null && reference.get() != null) { arg0.removeView(reference.get()); } } @Override public Object instantiateItem(ViewGroup arg0,final int arg1) { SoftReference<View> reference = ivs.get(arg1); if (reference == null || reference.get() == null) { View v = LayoutInflater.from(context).inflate(R.layout.item_show_more_image,null); reference = new SoftReference<View>(v); ivs.put(arg1,reference); } View v = reference.get(); final ViewHolder holder = new ViewHolder(v); Glide.with(context).asBitmap().load(images.get(arg1)).into(holder.image); arg0.addView(v); return v; } @Override public boolean isViewFromObject(View arg0,Object arg1) { return arg0.equals(arg1); } class ViewHolder { @FindId(R.id.image) private ImageView image; @FindId(R.id.rl_percent) private RelativeLayout rl_percent; @FindId(R.id.tv_percent) private TextView tv_percent; @FindId(R.id.iv_top) private ImageView iv_top; public ViewHolder(View v) { AutoFindId.findIdByView(this,v); } } }
對應佈局:
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@android:color/black" android:orientation="vertical" > <FrameLayout android:layout_width="match_parent" android:layout_height="match_parent" android:layout_marginBottom="50dp" android:layout_marginTop="70dp" > <ImageView android:layout_gravity="center" android:id="@+id/image" android:layout_width="match_parent" android:layout_height="match_parent" /> <ImageView android:id="@+id/iv_top" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="top|right" android:visibility="gone" android:background="@drawable/shuiyin" /> </FrameLayout> <RelativeLayout android:visibility="gone" android:id="@+id/rl_percent" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" > <ProgressBar android:layout_width="40dp" android:layout_height="40dp" /> <TextView android:id="@+id/tv_percent" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:textColor="@android:color/white" android:textSize="12sp" /> </RelativeLayout> </RelativeLayout>
上面都是次要的,因為我發現了一個更為簡便的輪子。
github地址
在我的專案中,我只需要兩步就完成了此功能。
第一步:
// 檢視大圖 implementation 'com.github.SherlockGougou:BigImageViewPager:v4_6.1.1'
第二步:
在點選圖片事件那裡呼叫:
ImagePreview .getInstance() // 上下文,必須是activity,不需要擔心記憶體洩漏,本框架已經處理好; .setContext(context) // 設定從第幾張開始看(索引從0開始) .setIndex(position) // 有三種設定資料集合的方式,根據自己的需求進行三選一: // 1:第一步生成的imageInfo List //.setImageInfoList(imageInfoList) // 2:直接傳url List .setImageList(imageList) // 3:只有一張圖片的情況,可以直接傳入這張圖片的url //.setImage(String image) // 開啟預覽 .start();
就這樣完成了圖片放大瀏覽、下載的功能,在這裡記錄下。
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支援我們。