儲存ArrayList至SharedPreferences
其中ArrayList中每個元素為String
List<String> environmentList = new ArrayList<String>();
SharedPreferences.Editor editor = getSharedPreferences("EnvironDataList", MODE_PRIVATE).edit();
editor.putInt("EnvironNums", environmentList.size());
for (int i = 0; i < environmentList.size(); i++)
{
editor.putString("item_"+i, environmentList.get(i));
}
editor.commit();
對應的取出操作為:
List<String> environmentList = new ArrayList<String>();
SharedPreferences preferDataList = getSharedPreferences("EnvironDataList", MODE_PRIVATE);
int environNums = preferDataList.getInt("EnvironNums", 0);
for (int i = 0; i < environNums; i++)
{
String environItem = preferDataList.getString("item_"+i, null);
environmentList.add(environItem);
}
儲存ArrayList至SharedPreferences,其中list的每個元素為自定義對象
1 首先将自定義對象序列化
public class CoordinateAlterSample implements Serializable {
private double x;
private double y;
private String name;
public double getX() {
return x;
}
public void setX(double x) {
this.x = x;
}
public double getY() {
return y;
}
public void setY(double y) {
this.y = y;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
其次,将list轉為json,即可儲存到SharedPreferences中
List<CoordinateAlterSample> alterSamples = new ArrayList<CoordinateAlterSample>();
SharedPreferences.Editor editor = getSharedPreferences("AlterSamplesList", MODE_PRIVATE).edit();
Gson gson = new Gson();
String json = gson.toJson(alterSamples);
Log.d(TAG, "saved json is "+ json);
editor.putString("alterSampleJson", json);
editor.commit();
SharedPreferences preferences = getSharedPreferences("AlterSamplesList", MODE_PRIVATE);
String json = preferences.getString("alterSampleJson", null);
if (json != null)
{
Gson gson = new Gson();
Type type = new TypeToken<List<CoordinateAlterSample>>(){}.getType();
List<CoordinateAlterSample> alterSamples = new ArrayList<CoordinateAlterSample>();
alterSamples = gson.fromJson(json, type);
for(int i = 0; i < alterSamples.size(); i++)
{
Log.d(TAG, alterSamples.get(i).getName()+":" + alterSamples.get(i).getX() + "," + alterSamples.get(i).getY());
}
}
作者: 一點點征服
本文版權歸作者所有,歡迎轉載,但未經作者同意必須保留此段聲明,且在文章頁面明顯位置給出原文連結,否則保留追究法律責任的權利