Question

我想在单击按钮时将用户输入保存到SharedPreferences，以便当用户再次启动活动时，用户输入将设置为EditText和TextView。我已经创建了一个sharedPreferences文件，我将一些文本保存到以前的活动中。我想用我创建的这个新活动的其他细节更新SharedPreferences文件。

这是用于创建和保存到SharedPreferences

的代码

viewDidLoad()

这是我将代码首选项的值设置为EditText和TextView

的代码

WebDriver test_driver = new FirefoxDriver();

driver.findElement(By.id("element id"))

Answer 1

File f = new File(PREF_FILE_NAME);只有偏好的名称 f.exists()将始终返回false

解决方案：删除

File f = new File(PREF_FILE_NAME);
if (f.exists()){

因为如果你没有任何价值，那么只需使用默认值

@Override
public void onStart(){
    super.onStart();
    //File f = new File(PREF_FILE_NAME); // not a right path
    //if (f.exists()){ // false
        idType = prefs.getInt("idType", 0);
        idNumber = prefs.getString("idNumber", "");
        expiryDate = prefs.getString("expiryDate", "");

        edtIdNumber = (EditText) findViewById(R.id.edtIdNumber);
        txtDate = (TextView) findViewById(R.id.txtDate);
        txtDate.setText(expiryDate);
        edtIdNumber.setText(idNumber);
        edtIdNumber.setText(idNumber);
        txtDate.setText(expiryDate);

    //}
}

或者您可以使用contains

Answer 2

要实现你的工作：首先尝试理解android中onCreate（）和onStart（）方法之间的区别，遵循以下url：https://developer.android.com/guide/components/activities/activity-lifecycle.html - ：使用onCreate（）方法而不是onStart（）来设置ui变量;

其次更改您的代码，如：

public void onClick(View view) {
            expiryDate = txtDate.getText().toString();
            edtIdNumber = (EditText) findViewById(R.id.edtIdNumber);
            idNumber = edtIdNumber.getText().toString();
            SharedPreferences.Editor editor = prefs.edit();
            editor.putInt("idType", idType);
            editor.putString("idNumber", idNumber);
            editor.putString("expiryDate", expiryDate);
            editor.commit();
        }

Answer 3

只需从Private Sub Button1_Click(sender As Object, e As EventArgs) Handles btnRegister.Click Dim firstname, lastname, email, mobile, level, currentschool, currenttrack, institution1, institution2, institution3, institution4, institution5, institution6, courses1, courses2, courses3 As String firstname = txtFName.Text lastname = txtLName.Text email = txtEmail.Text mobile = txtMobile.Text level = cmbLevel.Text currentschool = cmbCurrentSchool.Text currenttrack = cmbCurrentTrack.Text institution1 = cmbInstitution1.Text institution2 = cmbInstitution2.Text institution3 = cmbInstitution3.Text institution4 = cmbInstitution4.Text institution5 = cmbInstitution5.Text institution6 = cmbInstitution6.Text courses1 = cmbCourse1.Text courses2 = cmbCourse2.Text courses3 = cmbCourse3.Text Using sw As StreamWriter = File.AppendText("C:\Users\jmrosales\Documents\RegistrationForm\Registered.txt") sw.WriteLine(firstname & "~" & lastname & "~" & email & "~" & mobile & "~" & level & "~" & currentschool & "~" & currenttrack & "~" & institution1 & "~" & institution2 & "~" & institution3 & "~" & institution4 & "~" & institution5 & "~" & institution6 & "~" & courses1 & "~" & courses2 & "~" & courses3) End Using MsgBox("Registration Complete!") End Sub移除if (f.exists())条件，因为Onstart()只有首选项的名称，因此File f = new File(PREF_FILE_NAME);将始终返回false

，如下面的代码

f.exists()

将用户输入保存到SharedPrefernces并将Value设置为EdiText

3 个答案: