Question

这是我用于Android app的代码。这是数组索引出界问题即将到来。之后该应用程序崩溃。任何人都可以帮助我。

private void displayAvailableProjects() {
    projectList = databaseHelper.getAllProjects();
    if (projectList.size() >= 0) {   //here chnages =
        projectViewContainer.setVisibility(View.VISIBLE);
        ArrayList<String> projects = new ArrayList<>();
        projects.add("Previous Report");
        for (ProjectEntity project : projectList) {
            projects.add(project.getProjectName());
        }
        ArrayAdapter<String> projectListAdapter =
                new ArrayAdapter<String>(Projectinfo.this, android.R.layout.simple_list_item_1, projects);
        spinnerProject.setAdapter(projectListAdapter);
        spinnerProject.setSelected(false);
    } else {
        projectViewContainer.setVisibility(View.GONE);
    }
}
if (spinnerProject.getSelectedItemPosition() !=0)
                   openProjectFeedbackActivity(projectList.get(spinnerProject.getSelectedItemPosition()).getProjectId());

Answer 1

if (projectList.size() >= 0)

这一行是问题所在。您的projectList大小为0，但您正在显示列表

将其更改为

 if (projectList.size() > 0)

Answer 2

试试这个，

private void displayAvailableProjects() {
try{
    projectList = databaseHelper.getAllProjects();

    if (projectList.size() > 0) {   //here chnages =
        projectViewContainer.setVisibility(View.VISIBLE);
        ArrayList<String> projects = new ArrayList<>();
        projects.add("Previous Report");
        for (ProjectEntity project : projectList) {
           projects.add(project.getProjectName());
        }
        ArrayAdapter<String> projectListAdapter =
            new ArrayAdapter<String>(Projectinfo.this,android.R.layout.simple_list_item_1, projects);
        spinnerProject.setAdapter(projectListAdapter);
        spinnerProject.setSelected(false);
    } else {
    projectViewContainer.setVisibility(View.GONE);
   }
 }catch(Exception e){
  e.printstack();
 }
} 
if (spinnerProject.getSelectedItemPosition() !=0)openProjectFeedbackActivity(projectList.get(spinnerProject.getSelectedItemPosition()).getProjectId());

Answer 3

projectList = databaseHelper.getAllProjects();此行可能是您的问题。请检查您是否从数据库中获取了正确的数据。

当我点击查看按钮时，数组索引超出范围

3 个答案: