android viewpager+fragment 避免預載入，快取
阿新 • • 發佈：2019-01-27
一、需求是這樣的：滑動到哪一頁就在家一頁的資料，避免預載入
二、由於使用setOffScreenLimit無效
解決辦法：
<span style="color:#ff6666;">注意：setUserVisibleHint，使用這個方法來完成切換到哪一頁才載入哪一頁</span>
/** * * * @author Administrator * */ public class GestateKnowledgeBabyTabFragment extends TabBaseFragment implements LmbRequestCallBack { /** tab對應的幫的資料來源 */ private GestateBabyDataItem babyDataItem; /** tab對應幫分類Id */ private int babyTabId; /** 快取當前fragment顯示的view，用以當銷燬view但fragment沒銷燬時的回覆 */ private View cacheFragmentView; /** 當前fragment是否是可見的 */ private boolean isFragmentVisible; /** 是否已經載入了view,若已經載入了，不會再執行 */ private boolean isPrepared; /** * * @Description : * @author:zhongwr * @param :babyTabId tab對應的id,不能為空 * @param :categoryBangList 如果不為空則資料已經載入過，不用再次請求，如果為空，表示資料沒請求過，則請求網路獲取資料 * @return :void */ public static GestateKnowledgeBabyTabFragment newInstance(int babyTabId, GestateBabyDataItem babyDataItem) { GestateKnowledgeBabyTabFragment bangFragment = new GestateKnowledgeBabyTabFragment(); Bundle argsBundle = new Bundle(); argsBundle.putInt("babyTabId", babyTabId); argsBundle.putSerializable("babyDataItem", babyDataItem); bangFragment.setArguments(argsBundle); return bangFragment; } /** * isVisibleToUser:true:表示該UI可以被當前使用者可見;false:表示不可見 是在oncreateView之前執行 * *<span style="color:#ff0000;"> 執行順序，用於預載入時，不會執行，第二次執行可見時，由於不會執行oncreateView，所以用此來載入第二次獲取 setUserVisibleHint false--setUserVisibleHint * true--onAttach--onCreate--onCreateView--onActivityCreated--onResume()</span> */ @Override public void setUserVisibleHint(boolean isVisibleToUser) { super.setUserVisibleHint(isVisibleToUser); // 直接使用isVisibleToUser不準確 isFragmentVisible = getUserVisibleHint(); // 第一次載入fragment(由於是viewpager可能是預載入，導致isFragmentVisible=false不可見)並執行此方法時， // mactivity==null,當滑動選中，此時activity已經賦值，並且isFragmentVisible=true,再次執行這方法時不會執行oncreateView if (null != activity && isFragmentVisible && !isPrepared) { onCreateContentView(LayoutInflater.from(activity), null); } } @Override public View onCreateViewComplete(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { Logcat.dLog("isFragmentVisible = " + isFragmentVisible); Logcat.dLog("babyTabId = " + babyTabId); if (null == cacheFragmentView && isFragmentVisible) { isPrepared = true; View view = cacheFragmentView = inflater.inflate(R.layout.gestate_baby_knowledge_fragment, null); activity = getActivity(); initView(view); initListener(); initData(); } return cacheFragmentView; } private void initView(View view) { } /** * * @description 更新資料 * @author zhongwr * @update 2015-11-28 下午6:17:49 */ private void updateViewData(GestateBabyDataItem babyDataItem) { if (null != babyDataItem) { setClickToReloadGone(); if (null != babyDataItem.bbchange_data && !Tools.isEmpty(babyDataItem.bbchange_data.title)) { llBabyChangeParent.setVisibility(View.VISIBLE); tvBabyChangeContent.setText(babyDataItem.bbchange_data.text); tvBabyChangeTitle.setText(babyDataItem.bbchange_data.title); } else { llBabyChangeParent.setVisibility(View.GONE); } // 營養提醒 if (null != babyDataItem.nutrition_data && !Tools.isEmpty(babyDataItem.nutrition_data.title)) { llNutritionParent.setVisibility(View.VISIBLE); tvNutritionContent.setText(babyDataItem.nutrition_data.text); tvNutritionTitle.setText(babyDataItem.nutrition_data.title); } else { llNutritionParent.setVisibility(View.GONE); } if (null != babyDataItem.early_data && !Tools.isEmpty(babyDataItem.early_data.title)) { llEarlyParent.setVisibility(View.VISIBLE); tvEarlyContent.setText(Html.fromHtml(babyDataItem.early_data.text)); tvEarlyTitle.setText(babyDataItem.early_data.title); setViewOnClickListener(llEarlyParent, babyDataItem.early_data.id); } else { llEarlyParent.setVisibility(View.GONE); } if (null != babyDataItem.month_data && !Tools.isEmpty(babyDataItem.month_data.title)) { llConfinementParent.setVisibility(View.VISIBLE); tvConfinementTitle.setText(babyDataItem.month_data.title); tvConfinementContentTitle.setText(babyDataItem.month_data.small_title); tvConfinementContent.setText(Html.fromHtml(babyDataItem.month_data.text)); imageLoader.displayImage(babyDataItem.month_data.pic, ivConfinementHeadPic, options565); setViewOnClickListener(llConfinementParent, babyDataItem.month_data.id); } else { llConfinementParent.setVisibility(View.GONE); } // 推薦閱讀 if (null != babyDataItem.tuijian_data && !Tools.isEmpty(babyDataItem.tuijian_data.title)) { llRecommendedParent.setVisibility(View.VISIBLE); tvRecommendedTitle.setText(babyDataItem.tuijian_data.title); tvRecommendedContentTitle.setText(babyDataItem.tuijian_data.small_title); tvRecommendedContent.setText(Html.fromHtml(babyDataItem.tuijian_data.text)); setBigImageView(babyDataItem.tuijian_data.pic, ivRecommendedPic); setViewOnClickListener(llRecommendedParent, babyDataItem.tuijian_data.id); } else { llRecommendedParent.setVisibility(View.GONE); } if (null != babyDataItem.expert_data && !Tools.isEmpty(babyDataItem.expert_data.title)) { llExpertParent.setVisibility(View.VISIBLE); tvExpertTitle.setText(babyDataItem.expert_data.title); tvExpertContentTitle.setText(babyDataItem.expert_data.small_title); tvExpertContent.setText(babyDataItem.expert_data.text); imageLoader.displayImage(babyDataItem.expert_data.pic, ivExpertHeadPic, options565); setViewOnClickListener(llExpertParent, babyDataItem.expert_data.id); } else { llExpertParent.setVisibility(View.GONE); } if (null != babyDataItem.expert_video_data && !Tools.isEmpty(babyDataItem.expert_video_data.title)) { llVideoParent.setVisibility(View.VISIBLE); tvVideoTitle.setText(babyDataItem.expert_video_data.title); tvVideoContent.setText(babyDataItem.expert_video_data.small_title); setBigImageView(babyDataItem.expert_video_data.pic, ivVideoPic); setViewOnClickListener(ivVideoPlay, babyDataItem.expert_video_data.id); } else { llVideoParent.setVisibility(View.GONE); } addTagView(babyDataItem.tag_data, flowLayoutTag); } else { setLoadDataEmpty(); } } /*** * * @description * @author zhongwr * @update 2015-11-30 下午6:09:53 */ private void setViewOnClickListener(View view, final String id) { view.setTag(id); view.setOnClickListener(clickViewJumpListener); } private OnClickListener clickViewJumpListener = new OnClickListener() { @Override public void onClick(View v) { String id = (String) v.getTag(); } }; /** * * @description 設定tag標籤 * @author zhongwr * @update 2015-11-12 下午6:18:07 */ private void addTagView(GestateBabyTagContainerItem containerItem, FlowLayout flowLayoutTag) { if (null == containerItem || Tools.isEmpty(containerItem.title) || Tools.isListEmpty(containerItem.list)) { llTagParent.setVisibility(View.GONE); return; } List<GestateBabyTagItem> tagList = containerItem.list; flowLayoutTag.removeAllViews(); llTagParent.setVisibility(View.VISIBLE); tvTagTitle.setText(containerItem.title); TextView bt = null; int padding = Tools.dip2px(activity, 12); GestateBabyTagItem tagItem; for (int i = 0; i < tagList.size(); i++) { tagItem = tagList.get(i); bt = new TextView(activity); bt.setText(tagItem.small_title != null ? tagItem.small_title : "未知"); bt.setTextColor(getResources().getColor(R.color.red1)); bt.setGravity(Gravity.CENTER); bt.setBackgroundResource(R.drawable.preg_tag_bg); bt.setTextSize(13); bt.setPadding(padding, 0, padding, 0); bt.setTag(tagItem); final String tagId = tagItem.id; final String title = tagItem.small_title; bt.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { KnowledgeLabelDetailActivity.startKnowledgeLabelDetailAct(activity, tagId, title, "1", null); } }); flowLayoutTag.addView(bt); } } private void initListener() { setReloadListener(new Reload() {// 出錯重新載入 @Override public void OnReloadClick(View view) { requestBabyKnowledgeData(); } }); } private void initData() { Bundle argsBundle = getArguments(); if (null != argsBundle) { babyTabId = argsBundle.getInt("babyTabId", 1); babyDataItem = (GestateBabyDataItem) argsBundle.getSerializable("babyDataItem"); } if (null == babyDataItem) { requestBabyKnowledgeData(); } else { updateViewData(babyDataItem); } } }
/** * 各類tab通用一個Basefragment ： 比如 各類tab： 功能： 出錯機制處理 * * @author Administrator * */ public abstract class TabBaseFragment extends BaseFragment { public ClickScreenToReload clickToReload; private FrameLayout mViewContainer; @Override public void onAttach(Activity activity) { super.onAttach(activity); this.activity = activity; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { if (null == mViewContainer) { View view = inflater.inflate(R.layout.mam_base_main, null); mViewContainer = (FrameLayout) view.findViewById(R.id.base_container); } onCreateContentView(inflater, savedInstanceState); return mViewContainer; } public void onCreateContentView(LayoutInflater inflater, Bundle savedInstanceState) { if (null != mViewContainer) { mViewContainer.removeAllViews(); RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT); clickToReload = new ClickScreenToReload(activity); clickToReload.setVisibility(View.GONE); View viewContent = onCreateViewComplete(inflater, mViewContainer, savedInstanceState); if (null != viewContent) { mViewContainer.addView(viewContent, lp); } mViewContainer.addView(clickToReload, lp); } } @Override public void onDestroyView() { super.onDestroyView(); ViewGroup parent = (ViewGroup) mViewContainer.getParent(); if (null != parent) {// 必須先清除父佈局中的child，否則會報錯“當前父佈局已經有了一個child，不能再新增” mViewContainer.removeAllViewsInLayout(); parent.removeView(mViewContainer); } } /*** * * @description 建立view * @author zhongwr * @update 2015-11-4 下午5:27:36 */ public abstract View onCreateViewComplete(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState); /** * * @description 設定網路不可見，點選重新載入 * @author zhongwr * @update 2015-11-4 下午5:07:12 */ protected void setReloadVisiable() { clickToReload.setVisibility(View.VISIBLE); clickToReload.setloadfail(); } /** * * @description 設定載入資料為空 * @author zhongwr * @update 2015-11-4 下午5:07:12 */ protected void setLoadDataEmpty() { clickToReload.setVisibility(View.VISIBLE); clickToReload.setloadEmpty(); } /** * * @description 設定正在載入 * @author zhongwr * @update 2015-11-4 下午5:08:29 */ protected void setLoadingVisiable() { clickToReload.setVisibility(View.VISIBLE); clickToReload.setLoading(); } /** * * @description 隱藏這個出錯介面 * @author zhongwr * @update 2015-11-4 下午5:09:24 */ protected void setClickToReloadGone() { clickToReload.setVisibility(View.GONE); } /** * * @description 重新載入的監聽器 * @author zhongwr * @update 2015-11-4 下午5:32:44 */ protected void setReloadListener(Reload reloadListener) { clickToReload.setReloadClick(reloadListener); } /** 螢幕的三分之一 */ private int screenWidthThirdOne = Tools.getScreenSize(activity).x / 3; /** * * @description 適配圖片大圖：圖片佈局除了間距顯示寬度充滿整個螢幕 * @author zhongwr * @update 2015-11-13 上午11:32:08 */ protected void setBigImageView(String picUrl, final ImageView ivPic) { imageLoader.displayImage(picUrl, ivPic, options565, new SimpleImageLoadingListener() { @Override public void onLoadingComplete(String imageUri, final View view, final Bitmap loadedImage) { if (null != loadedImage) {// 設定成背景，清除src否則重疊 ivPic.post(new Runnable() { @Override public void run() { int ivMeasureWidth = ivPic.getMeasuredWidth(); LayoutParams params = ivPic.getLayoutParams(); int bmWidth = loadedImage.getWidth(); if (bmWidth < screenWidthThirdOne) {// 處理小圖 params.height = LayoutParams.WRAP_CONTENT; params.width = bmWidth; } else if (ivMeasureWidth > 0) { // 按原圖的比例縮放 params.height = ivMeasureWidth * loadedImage.getHeight() / bmWidth; params.width = ivMeasureWidth; } ivPic.setBackgroundDrawable(null); ivPic.setImageDrawable(new BitmapDrawable(loadedImage)); } }); } else { ivPic.setImageDrawable(null);// 設定成背景，清除src否則重疊 ivPic.setBackgroundResource(R.drawable.default_user_head); } } @Override public void onLoadingFailed(String imageUri, View view, FailReason failReason) { ivPic.setImageDrawable(null);// 設定成背景，清除src否則重疊 ivPic.setBackgroundResource(R.drawable.default_user_head); } }); } }