基於透明fragment的長流程封裝技巧

是否厭煩了寫各類onActivityResult?不要急,透明fragment來幫你

雖然fragment坑死人不償命,可是不寫view,只做爲輔助功能來使用,仍是很好用的.

思路來自於:RxPermissionsFragment

基類

public abstract class BaseTransFragment extends Fragment {

    protected FragmentActivity activity;//自行保存activity引導,絕對不用getActivity()這個坑貨

    protected void setHostActivity(FragmentActivity activity) {
        this.activity = activity;
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRetainInstance(true);//避免旋轉時fragment銷燬重建
    }
}
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工具方法:

public static <T extends BaseTransFragment> T getTransFragment(FragmentActivity fragmentActivity,
            String fragmentTag, Callable<T> newIntance) {
        try {
            FragmentManager fragmentManager = fragmentActivity.getSupportFragmentManager();
            T fragment = findFragment(fragmentManager, fragmentTag);
            boolean isNewInstance = fragment == null;
            if (isNewInstance) {
                fragment = newIntance.call();
                fragmentManager.beginTransaction()
                        .add(fragment, fragmentTag)
                        .commitAllowingStateLoss();//避免數據保存和恢復致使的crash
                fragmentManager.executePendingTransactions();
            }
            fragment.setHostActivity(fragmentActivity);
            return fragment;
        } catch (Exception e) {
            e.printStackTrace();
            try {
                return newIntance.call();
            } catch (Exception e1) {
                e1.printStackTrace();
                return null;
            }
        }

    }

    private static <T extends BaseTransFragment> T findFragment(FragmentManager fragmentManager, String fragmentTag) {
        Fragment fragment = fragmentManager.findFragmentByTag(fragmentTag);
        if (fragment == null) {
            return null;
        }
        return (T) fragment;
    }
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例子:

1.寫了一個VendorPayTransFragment繼承basefragment,沒有界面,裏面封裝好了整套流程,處理了各類onactivityresult,權限,網絡請求等等,而後,提供一個靜態方法,提供輸入和回調:

public static void startOrder(FragmentActivity activity, BaseQRPayCalInfo info, IVendorPayCallback callback) {
        VendorPayTransFragment fragment = getTransFragment(activity, "offlineorder",
                new Callable<VendorPayTransFragment>() {
            @Override
            public VendorPayTransFragment call() throws Exception {
                return VendorPayTransFragment.newInstance(info);
            }
        });
        fragment.setCallback(callback);
        fragment.startScanOrder();
    }
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2. 拍照/圖片選擇-裁剪-壓縮整個流程,封裝成一個工具方法:

TakePhotoUtil.startPickOne(this, false, new TakeOnePhotoListener() {
            @Override
            public void onSuccess(String s) {
               showImg(filePath);
            }

            @Override
            public void onFail(String path, String msg) {
                MyToast.errorBigL(s1);
            }

            @Override
            public void onCancel() {
            }
        });
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