嘿伙计们，我有这个小问题。我是 Java 的新手，我只想弄清楚“如何在我的代码中的下面列表视图的末尾添加另一个项目”。这应该在程序运行时动态发生。我只想单击列表视图底部的相应空间并添加一个项目。有人可以帮助我解决这个问题。谢谢！
注意：运行应用程序，一切都会出现在那里。我只想为这些按钮添加功能。当我单击“添加”按钮时，我应该能够添加更多项目。
package layoutsizingaligning;
import java.util.Scanner;
import javafx.application.Application;
import javafx.geometry.HPos;
import javafx.geometry.Insets;
import javafx.geometry.Orientation;
import javafx.scene.control.Control;
import javafx.scene.Scene;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Pos;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ListView;
import javafx.scene.control.PasswordField;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
import javafx.scene.control.TextField;
import javafx.scene.layout.*;
import javafx.stage.Stage;
/**
* Sample application that shows how the sized of controls can be managed.
* Sample is for demonstration purposes only, most controls are inactive.
*/
public class LayoutSizingAligning extends Application { …我是Java中的OOP概念的新手.这两起事件有什么区别？
1.
ClassName obj_name = new ClassName();
obj_name.method();
2.
new ClassName().method();
非常感谢一个很好的解释.谢谢
我用这个Python27的小代码内容得到了这个错误.谁能帮我这个？提前致谢.
运行时错误回溯(最近一次调用最后一次):文件"5eb4481881d51d6ece1c375c80f5e509.py",第57行,在print len(arr)中TypeError:'list'对象不可调用
global maximum
def _lis(arr , n ):
# to allow the access of global variable
global maximum
# Base Case
if n == 1 :
return 1
# maxEndingHere is the length of LIS ending with arr[n-1]
maxEndingHere = 1
"""Recursively get all LIS ending with arr[0], arr[1]..arr[n-2]
IF arr[n-1] is maller than arr[n-1], and max ending with
arr[n-1] needs to be updated, then update it"""
for i in xrange(1, n):
res = _lis(arr , i)
if …我有这个递归函数，它不会编译在向量连接行给出错误。
vector<int> binaryInsert(vector<int> subArray, int subArraySize, int nextVal) {
if(subArraySize == 1)
{
if(nextVal >= subArray[0]) subArray.insert(subArray.begin()+1, nextVal);
else subArray.insert(subArray.begin(), nextVal);
return subArray;
}
else if(subArraySize == 2)
{
if(nextVal >= subArray[0]) {
if(nextVal >= subArray[1]) subArray.insert(subArray.begin()+2, nextVal);
else subArray.insert(subArray.begin()+1, nextVal);
}
else subArray.insert(subArray.begin(), nextVal);
return subArray;
}
else
{
if(subArraySize%2 == 1)
{
int halfPoint = (subArraySize-1)/2;
vector<int> leftSubArray(subArray.begin(), subArray.begin()+halfPoint);
vector<int> rightSubArray(subArray.begin()+halfPoint, subArray.end());
vector<int> newVec;
if(nextVal <= leftSubArray[halfPoint-1]) {
newVec = binaryInsert(leftSubArray, halfPoint, nextVal);
return newVec.insert(newVec.end(), rightSubArray.begin(), rightSubArray.end());
} …