一延曙、為什么要寫(xiě) startActivityForResult()
在實(shí)際項(xiàng)目中我們會(huì)有這樣的應(yīng)用場(chǎng)景豌鹤，在 Activity1 的 Fragment1 中的某個(gè)點(diǎn)擊事件，跳轉(zhuǎn)到另一個(gè) Activity2 的 Fragment2 中布疙，而 Fragment2 需要返回一些數(shù)據(jù)給 Fragment1，這時(shí)候我們?cè)撛趺崔k呢
通過(guò) Fragment 的 startActivityForResult() 方法可以完成上述的操作愿卸，但是這又跟我們平時(shí)的 Activity 的 startActivityForResult() 不一樣， Fragment 沒(méi)有 setResult() 方法趴荸，無(wú)法設(shè)置返回的數(shù)據(jù)儒溉。
正確的操作思路是：Fragment1 調(diào)用 startActivityForResult() 方法之后，跳轉(zhuǎn)到 Activity2 中顿涣，Activity2 先把數(shù)據(jù)取出來(lái)，然后通過(guò) Bundle 把數(shù)據(jù)設(shè)置給 Fragment2 酝豪，F(xiàn)ragment2 把數(shù)據(jù)取出來(lái)，然后調(diào)用 getActivity().setResult() 方法設(shè)置返回?cái)?shù)據(jù)孵淘，然后在 Fragment1 的 onActivityResult() 中拿到返回的數(shù)據(jù)
二蒲障、實(shí)際操作
2.1 Fragment1，即 FirstFragment 代碼如下：
public class FirstFragment extends Fragment {
@BindView(R.id.listview)
ListView listview;
private String name;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
Log.i("FirstFragment", "onCreateView");
View inflate = inflater.inflate(R.layout.huituizhan_first_fragment, container, false);
ButterKnife.bind(this, inflate);
initListViewData();
return inflate;
}
private void initListViewData() {
list = new ArrayList<>();
int m = 0;
for (int i = 0; i < 20; i++) {
list.add("珞神"+m);
m++;
}
myAdapter = new MyAdapter();
listview.setAdapter(myAdapter);
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//點(diǎn)擊跳轉(zhuǎn)
Intent intent = new Intent(getActivity(),ResultActivity.class);
intent.putExtra("item",position+"");
startActivityForResult(intent,0);
}
});
}
/**
* 調(diào)用 startActivityForResult 后揉阎，目標(biāo)activity 返回的數(shù)據(jù)會(huì)在這個(gè)方法內(nèi)
* @param requestCode
* @param resultCode
* @param data
*/
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
list.add(requestCode+resultCode+data.getStringExtra("item"));
myAdapter.notifyDataSetChanged();
}
private ArrayList<String> list;
private MyAdapter myAdapter;
public class MyAdapter extends BaseAdapter {
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = null;
ViewHolder viewHolder;
if (convertView == null) {
view = View.inflate(getActivity(), R.layout.litt_item, null);
viewHolder = new ViewHolder(view);
view.setTag(viewHolder);
}else {
view = convertView;
viewHolder = (ViewHolder) view.getTag();
}
viewHolder.listText.setText(list.get(position));
return view;
}
}
static class ViewHolder {
@BindView(R.id.list_text)
TextView listText;
ViewHolder(View view) {
ButterKnife.bind(this, view);
}
}
}
2.2 Activity2 即 ResultActivity 的代碼如下：
public class ResultActivity extends AppCompatActivity {
@BindView(R.id.framelayout_resultfragment)
FrameLayout framelayoutResultfragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sencond);
ButterKnife.bind(this);
//取出傳遞過(guò)來(lái)的數(shù)據(jù)痛悯， 注意 newInstance 方法設(shè)置的有 Bundle
String title = getIntent().getStringExtra("item");
ResultFragment resultFragment = ResultFragment.newInstance(title);
getSupportFragmentManager()
.beginTransaction()
.add(R.id.framelayout_resultfragment,resultFragment,"resultfragment")
.commit();
}
}
注意：ResultFragment 一定要是同一個(gè)對(duì)象余黎，不要?jiǎng)?chuàng)建兩個(gè)對(duì)象
2.3 Fragment2 即 ResultFragment 的代碼如下：
package com.example.administrator.fragment_text.huituizhan;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.example.administrator.fragment_text.R;
public class ResultFragment extends Fragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle bundle = getArguments();
if (bundle != null) {
String item = bundle.getString("item");
Log.i("ResultFragment",item+"");
Intent intent = new Intent();
intent.putExtra("item","result");
getActivity().setResult(1,intent);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_result, container, false);
}
//返回 resultFragment 對(duì)象，并把傳遞過(guò)來(lái)的數(shù)據(jù)設(shè)置在 bundle 中
public static ResultFragment newInstance(String argument){
Bundle bundle = new Bundle();
bundle.putString("item", argument);
ResultFragment resultFragment = new ResultFragment();
resultFragment.setArguments(bundle);
return resultFragment;
}
}
注意： 這里的邏輯是惧财，在創(chuàng)建 ResultFragment 對(duì)象的時(shí)候，就把數(shù)據(jù)設(shè)置進(jìn) Bundle 中了扭仁，然后在 onCreate 方法中取出 bundle 中的數(shù)據(jù)垮衷，并設(shè)置返回的數(shù)據(jù)乖坠。
