Question

我正在构建一个使用搜索引擎搜索网络的应用。我的应用程序中有一个edittext，用户将从中搜索网页。我想像浏览器历史一样保存搜索关键字。我可以使用最后一个关键字保存并显示它，但我不能增加搜索结果的数量。我想显示最近的5个searhes。这是我的代码：

public class MainActivity extends Activity implements OnClickListener {

Button insert;
EditText edt;
TextView txt1, txt2, txt3, txt4, txt5;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    edt = (EditText) findViewById(R.id.search_word);

    txt1 = (TextView) findViewById(R.id.txt1);
    txt1.setOnClickListener(this);

    insert = (Button) findViewById(R.id.insert);
    insert.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {
            if ((edt.getText().toString().equals(""))) {
                Toast.makeText(
                        getBaseContext(),
                        "Whoa! You haven't entered anything in the search box.",
                        Toast.LENGTH_SHORT).show();

            } else {
                SharedPreferences app_preferences = PreferenceManager
                        .getDefaultSharedPreferences(MainActivity.this);
                SharedPreferences.Editor editor = app_preferences.edit();
                String text = edt.getText().toString();
                editor.putString("key", text);
                editor.commit();
                Toast.makeText(getBaseContext(), text, Toast.LENGTH_LONG)
                        .show();
            }

        }
    });
}

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

    SharedPreferences app_preferences = PreferenceManager
            .getDefaultSharedPreferences(this);
    String text = app_preferences.getString("key", "null");
    txt1.setText(text);
}

public void onClick(View v) {
    String text = txt1.getText().toString();
    Toast.makeText(getBaseContext(), text, Toast.LENGTH_SHORT).show();

}

}

请帮助我克服这个问题。

Answer 1

保存阵列

public boolean saveArray(String[] array, String arrayName, Context mContext) {   
    SharedPreferences prefs = mContext.getSharedPreferences("preferencename", 0);  
    SharedPreferences.Editor editor = prefs.edit();  
    editor.putInt(arrayName +"_size", array.length);  
    for(int i=0;i<array.length;i++)  
        editor.putString(arrayName + "_" + i, array[i]);  
    return editor.commit();  
}

LOAD ARRAY

public String[] loadArray(String arrayName, Context mContext) {  
    SharedPreferences prefs = mContext.getSharedPreferences("preferencename", 0);  
    int size = prefs.getInt(arrayName + "_size", 0);  
    String array[] = new String[size];  
    for(int i=0;i<size;i++)  
        array[i] = prefs.getString(arrayName + "_" + i, null);  
    return array;  
}

Answer 2

使用Gson库将数组或对象转换为Json，并以json格式将数据存储为String。

保存;

SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(context);
Editor editor = sharedPrefs.edit();
Gson gson = new Gson();

String json = gson.toJson(arrayList);

editor.putString(TAG, json);
editor.commit();

读取;

SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(context);
Gson gson = new Gson();
String json = sharedPrefs.getString(TAG, null);
Type type = new TypeToken<ArrayList<ArrayObject>>() {}.getType();
ArrayList<ArrayObject> arrayList = gson.fromJson(json, type);

原始答案：Storing Array List Object in SharedPreferences

Android：如何在Android的SharedPreferences中存储字符串数组

2 个答案: