[英]Put an ArrayList<String> into an ArrayList<Custom Object>
我從共享首選項中獲取數據:
SharedPreferences sharedPref = ImageListViewActivity.this.getSharedPreferences("settings",Context.MODE_PRIVATE;
String MyString1 = sharedPref.getString("MyPackage.NameOfSharedPref",null);
String MyString2 = sharedPref.getString("MyPackage.NameOfSharedPref",null);
String MyString3 = sharedPref.getString("MyPackage.NameOfSharedPref",null);
看起來像:
MyString1 = "Ben, David, Tom, Jessica"
MyString2 = "25, 27, 21, 22"
MyString3 = "male, male, male, female"
我將其拆分為字符串數組:
String[] splitt1 = MyString1.split(",");
String[] splitt2 = MyString2.split(",");
String[] splitt3 = MyString3.split(",");
現在我把它放到一個 ArrayList 中:
ArrayList<String> arrayList1 = new ArrayList<String>();
for (int i = 0; i < MyString1.length; i++) {
arrayList1 .add(MyString1[i]);
}
ArrayList<String> arrayList2 = new ArrayList<String>();
for (int i = 0; i < MyString2.length; i++) {
arrayList2 .add(MyString2[i]);
}
ArrayList<String> arrayList3 = new ArrayList<String>();
for (int i = 0; i < MyString3.length; i++) {
arrayList3 .add(MyString3[i]);
}
如何將 ArrayList 的值放入自定義對象數組? 我有一個帶有構造函數、getter 和 setter 的對象類。
public class Student {
private String Name;
private String Age;
private String Sex;
public Student(String name, String age, String sex) {
this.Name = name;
this.Age = age;
this.Sex = sex;
}
public String getName() {
return Name;
}
public void setName(String artikelnummer) {
Name = name;
}
public String getAge() {
return Age;
}
public void setAge(String artikelnummer) {
Age = age;
}
public String getSex() {
return sex;
}
public void setSex(String artikelnummer) {
Sex = sex;
}
現在我想填充我的學生對象數組,我試過這種方式,但這是我填充的字符串數組,它不起作用:
ArrayList<Students> peopleList = new ArrayList<>();
for (int i = 0; i < splitt1.length; i++) {
peoplelist.add(splitt1[i]);
}
我想對我的 ArrayLists 進行排序並將它們寫入這樣的 ObjectArrayList 中:
Student Stu1 = new Student("Ben","25","male");
Student Stu2 = new Student("David","27","male");
Student Stu3 = new Student("Tom","21","male");
Student Stu4 = new Student("Jessica","22","female");
請幫幫我,謝謝您的期待!
您必須創建一個Student
對象,例如
for (int i = 0; i < splitt1.length; i++) {
String name = splitt1[i].trim(); remove whitespaces
String age = splitt2[i].trim(); remove whitespaces
String gender = splitt3[i].trim(); remove whitespaces
peoplelist.add(new Student(name, age, gender));
}
到目前為止,這將解決您的問題。 你必須記住你的ArrayList
的長度必須完全相同,否則你會得到IndexOutOfBondException
。
試試這個代碼
ArrayList<Student> peopleList = new ArrayList<>();
for (int i = 0; i < splitt1.length; i++) {
Student Student = new Student(splitt1[i],splitt2[i],splitt[i]);
peoplelist.add(Student );
}
將模型類名稱從學生更改為學生
因為你有相同大小的字符串:
MyString1 = "Ben, David, Tom, Jessica"
MyString2 = "25, 27, 21, 22"
MyString3 = "male, male, male, female"
您可以從中獲得:
String[] splitt1 = MyString1.split(",");
String[] splitt2 = MyString2.split(",");
String[] splitt3 = MyString3.split(",");
您可以使用拆分字符串的長度作為 for 循環計數。
您需要從您的Students
pojo創建 Student 列表(應該是Student
來描述單個對象)。 從你的 pojo 中,你有一個構造函數:
public Student(String name, String age, String sex) {
...
}
因此,您可以使用它來創建 Student 對象。 因此,您可以使用以下代碼:
List<Students> students = new ArrayList<>();
// using splitt1.length - 1 because index is starting from zero for list.
for (int i = 0; i < splitt1.length - 1; i++) {
// use .trim() for removing extra whitespace.
Students student = new Student(splitt1[i].trim(), splitt2[i].trim(), splitt3[i].trim());
students.add(student);
}
邊注:
您可以使用 Gson 將對象保存到 SharedPreference,而不是使用字符串的單個首選項條目,閱讀更多內容,請訪問https://stackoverflow.com/a/38089938/4758255
用這個
ArrayList<String> arrayList1 = new ArrayList<String>();
for (int i = 0; i < splitt1.length; i++) {
arrayList1 .add(splitt1[i]);
}
ArrayList<String> arrayList2 = new ArrayList<String>();
for (int i = 0; i < splitt2.length; i++) {
arrayList2 .add(splitt2[i]);
}
ArrayList<String> arrayList3 = new ArrayList<String>();
for (int i = 0; i < splitt3.length; i++) {
arrayList3 .add(splitt3[i]);
}
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