Question

我的问题是：如何将项目位置传递给另一个班级。请参阅我附带的代码。

当我在AlertDialog中按下正按钮时，我转到HandleAlertDialog类，然后我按ID删除Name（在数据库中我有两个变量：id和name）。

我不知道如何在HandleAlertDialog类中将id从项目位置传递到sqhelper.deleteNameByNumber（ id ）。

感谢您的帮助。

public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
        AlertDialog dialog = new AlertDialog.Builder(this) 
            .setMessage("Choose one of the options")
            .setPositiveButton("Yes", new HandleAlertDialog())
            .setNeutralButton("No",new HandleAlertDialog())
            .setCancelable(false)
            .create();
        dialog.show();
        return false;
      }

    public  class  HandleAlertDialog implements DialogInterface.OnClickListener {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            if (which==-1){
                sqhelper.deleteNameByNumber(**???**);
            }
        }
    }

Answer 1

您可以在id类中定义HandleAlertDialog属性（我假设这是String我的例子）：

public  class  HandleAlertDialog implements DialogInterface.OnClickListener {
    private String id;

    public HandleAlertDialog(String id){
        this.id = id;
    }

    @Override
    public void onClick(DialogInterface dialog, int which) {
        if (which==-1){
            sqhelper.deleteNameByNumber(id);
        }
    }
}

然后在onItemLongClick：

中使用它

public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {

    // Retrieve id here (based on view, position ?)
    String id = "THIS IS YOUR ID";
    HandleAlertDialog handleAlertDialog = new HandleAlertDialog(id);

    AlertDialog dialog = new AlertDialog.Builder(this) 
        .setMessage("Choose one of the options")
        .setPositiveButton("Yes", handleAlertDialog)
        .setNeutralButton("No", handleAlertDialog)
        .setCancelable(false)
        .create();
    dialog.show();
    return false;
}

Answer 2

只需在构造函数中传递id。

public boolean onItemLongClick (AdapterView parent, View view,int position, final long id){
        AlertDialog dialog = new AlertDialog.Builder(this)

                .setMessage("Choose one of the options")
                .setPositiveButton("Yes", new HandleAlertDialog(id))
                .setNeutralButton("No", new HandleAlertDialog(id))
                .setCancelable(false)
                .create();
        dialog.show();

        return false;
    }

添加构造函数。

public  class  HandleAlertDialog implements DialogInterface.OnClickListener
{
    long id;

    public HandleAlertDialog(long id) {
        this.id = id;
    }

    @Override
    public void onClick(DialogInterface dialog, int which) {
        if (which==-1){
            sqhelper.deleteNameByNumber(id);
        }
    }
}

如果不清楚，请告诉我。

如何将项目位置从onItemLongClick传递到另一个类？

2 个答案: