Question

我尝试根据数据库是否存在来创建一个切换到2个活动之一的按钮。我已经创建了一个databasecheckhelper，但由于某种原因，即使数据库存在，它仍然会发出错误。

单击按钮时的

代码：

public void open_my_training(View view) {

    Intent intent;

    boolean databaseExists = checkDatabase.checkDB(this);
    if(databaseExists){
        intent = new Intent(this, a.class);
    }else{
        intent = new Intent(this, b.class);
    }
    startActivity(intent);
}

帮助者

public class checkDatabase {

    public static boolean checkDB(Context context) {
        File dbFile = context.getDatabasePath("database.db");
        return dbFile.exists();
    }
}

谁能告诉我我做错了什么？

编辑：

由于代码似乎很好，我将添加用于创建数据库的代码：

public void save_training(View view) {

    CheckBox box1 = (CheckBox) findViewById(R.id.box1);
    CheckBox box2 = (CheckBox) findViewById(R.id.box2);


    Spinner spinner1 = (Spinner) findViewById(R.id.spinner1);
    String spinner1 = spinner1.getSelectedItem().toString();

    createDatabase();
    addTraining(box1.isChecked(), box2.isChecked(), spinner1);
}


private void createDatabase() {
    try {

        trainingDB = this.openOrCreateDatabase("database.sqlite", MODE_PRIVATE, null);

        trainingDB.execSQL("CREATE TABLE IF NOT EXISTS table1" + "(id integer primary key," +
                "box1 boolean, box2 boolean, + "spinner1 VARCHAR);");

}

private void addTraining(boolean box1Checked, boolean box2Checked, String spinner1) {

    trainingDB.execSQL("INSERT INTO table1 (box1, box2, spinner1) VALUES ('"+ box1Checked + "', '" +
            box2Checked + "', '" + spinner1 + "');");
}

Answer 1

替换

File dbFile = context.getDatabasePath("database.sqlite");

而不是

File dbFile = context.getDatabasePath("database.db");

Android为什么我的checkDB一直给出错误？

1 个答案: