SharedPreferences经常用来储存一些默认欢迎语,用户登录名和密码等简单信息,一般用于存储量小的信息
exampleHelper.java
import android.content.Context;
import android.content.SharedPreferences;
/**
* Created by 6lang on 2018/10/6.
*/
public class exampleHelper {
SharedPreferences sp;
SharedPreferences.Editor editor;
Context context;
public exampleHelper(Context c,String name)
{
context=c;
sp=context.getSharedPreferences(name,0);
editor=sp.edit();
}
public void putValue(String key,String value)
{
editor=sp.edit();
editor.putString(key,value);
editor.commit();
}
public String getValue(String key)
{
return sp.getString(key,null);
}
}
1getSharedPreferences(文件名称,操作模式) .得到SharedPreferences对象,0表示默认模式
2.editor=sp.edit(); 获取一个Edit对象,所有对数据的操作都需要经过Edit
3.editor.commit(); 提交是必须的
MainActivity.java
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
public final static String COLUMN_NAME="name";
public final static String COLUMN_MOBILE="mobile";
exampleHelper sp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sp=new exampleHelper(this,"contact");
//设置储存的信息
sp.putValue(COLUMN_NAME,"Mr Wang");
sp.putValue(COLUMN_MOBILE,"13223346556");
String name=sp.getValue(COLUMN_NAME);
String mobile=sp.getValue(COLUMN_MOBILE);
TextView tv=new TextView(this);
tv.setText("NAME:"+name+"\n"+"MOBILE:"+mobile);
setContentView(tv);
}
}