跨应用读取SharedPreference数据

package com.example.atest_sp;

import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends Activity {
private EditText et;
private Button btn;

public static final String FILE_NAME = "_filename";
public static final String KEY = "_key";

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

et = (EditText) findViewById(R.id.et);
btn = (Button) findViewById(R.id.btn);

btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
SharedPreferences share = getSharedPreferences(FILE_NAME, Context.MODE_WORLD_READABLE);
share.edit().putString(KEY, et.getText().toString()).commit();
}
});

}

}

package com.example.btest_sp;

import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {
private TextView tv;
private Button btn;

public static final String A_PKG_NAME = "com.example.atest_sp";
public static final String FILE_NAME = "_filename";
public static final String KEY = "_key";

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

tv = (TextView) findViewById(R.id.tv);
btn = (Button) findViewById(R.id.btn);

btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
try {
SharedPreferences share = getTargetContext().getSharedPreferences(FILE_NAME,
Context.MODE_WORLD_READABLE | Context.MODE_MULTI_PROCESS);
String afterBooleanValue = share.getString(KEY, "");
tv.setText(afterBooleanValue + "");
} catch (NameNotFoundException e) {
e.printStackTrace();
tv.setText("没有找到该包名");
}
}
});
}

private Context getTargetContext() throws NameNotFoundException {
return createPackageContext(A_PKG_NAME, Context.CONTEXT_IGNORE_SECURITY);
}

}