android - 打开 xml 页面时遇到问题

Question

我创建了两个 java 类和两个 xml 页面。我试图在一个班级的点击按钮时，打开另一个班级。打开后，memo.xml 页面显示空白。请参阅以下代码。请帮我

我的 login.java 页面：

package quesansw.the1;
import android.app.Activity;
import android.app.Dialog;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.text.Editable;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class Login extends Activity{

    SQLiteDatabase db;
    int z,i=0;
    String[] arr = new String[3];
public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        db = openOrCreateDatabase("mydatabase.db",
                SQLiteDatabase.CREATE_IF_NECESSARY, null);

        final Dialog d1 = new Dialog(this);
        Window window = d1.getWindow();
        window.setFlags(WindowManager.LayoutParams.FLAG_BLUR_BEHIND,
                WindowManager.LayoutParams.FLAG_BLUR_BEHIND);

        d1.setTitle("Login");

        d1.setContentView(R.layout.login);

        d1.show();
        Button registerques1 = (Button) d1.findViewById(R.id.registerques1);
        EditText ques = (EditText) d1.findViewById(R.id.question);


        Cursor cur= db.rawQuery("select * from questions1",null);
        cur.moveToNext();
        System.out.println(cur.getString(0));
        System.out.println(cur.getString(1));
        ques.append(cur.getString(0));

        Cursor c = db.rawQuery("SELECT * from questions1", null);

        if (c != null ) {
            if  (c.moveToFirst()) {
                do {
                    String firstName = c.getString(c.getColumnIndex("question"));
                    String Name = c.getString(c.getColumnIndex("answer"));

                    arr[i]=firstName;
                    i++;
                    }while (c.moveToNext());
            } 
        }


        for(z=0;z<2;z++)
        {
            registerques1.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v)
            {

                if(z == 2)
                {
                Cursor cur= db.rawQuery("select * from questions1",null);
                cur.moveToNext();
                EditText ques = (EditText) d1.findViewById(R.id.question);
                EditText ans = (EditText) d1.findViewById(R.id.answer);
                Editable newTxt=(Editable)ans.getText(); 
                String str = newTxt.toString();
                int l=str.length();
                int l1=cur.getString(1).length();
                int l2=l-l1;
                ques.setText(arr[0]);
                ans.setText("");
                if(l2 == 0)
                {
                    z=5;
                }
                }

                if(z == 5)
                {
                    EditText ques = (EditText) d1.findViewById(R.id.question);
                    ques.setText(arr[1]);
                    Cursor cur= db.rawQuery("select * from questions1 where question='"+arr[1]+"' ",null);
                    cur.moveToNext();
                    //ques.setText();

                    EditText ans = (EditText) d1.findViewById(R.id.answer);
                    System.out.println("------"+ans.getText());
                    Editable newTxt=(Editable)ans.getText(); 
                    String str = newTxt.toString();
                    int l=str.length();
                    int l1=cur.getString(1).length();
                    int l2=l-l1;
                    ques.setText(arr[1]);
                    ans.setText("");
                    /*ques.setText(arr[2]);
                    ans.setText("");*/
                    if(l2 == 0)
                    {
                        /*Intent intent = new Intent(getBaseContext(), Memo.class);
                        startActivity(intent);*/
                        z=6;
                    }

                }

                if(z == 6)
                {
                    EditText ques = (EditText) d1.findViewById(R.id.question);
                    ques.setText(arr[2]);
                    Cursor cur= db.rawQuery("select * from questions1 where question='"+arr[2]+"' ",null);
                    cur.moveToNext();

                    EditText ans = (EditText) d1.findViewById(R.id.answer);
                    System.out.println("------"+ans.getText());
                    Editable newTxt=(Editable)ans.getText(); 
                    String str = newTxt.toString();
                    int l=str.length();
                    int l1=cur.getString(1).length();
                    //System.out.println(l+l1);
                    int l2=l-l1;
                    ques.setText(arr[2]);
                    ans.setText("");
                    if(l2 == 0)
                    {
                        System.out.println("memo-----");
                        Intent intent = new Intent(getBaseContext(), Memo.class);
                        startActivity(intent);
                    }

                }


            }
        });

        }

}
}

登录.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="match_parent">

<TextView android:text="Question1" android:id="@+id/TextView01" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
<EditText android:id="@+id/question" android:layout_width="match_parent" android:layout_height="wrap_content" android:text=""></EditText>
<EditText android:id="@+id/answer" android:layout_width="match_parent" android:layout_height="wrap_content" android:text=""></EditText>

<Button android:id="@+id/registerques1" android:layout_width="wrap_content" android:text="registerques" android:layout_height="wrap_content"></Button>

</LinearLayout>

备忘录.java

package quesansw.the1;

import android.app.Activity;
import android.app.Dialog;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;

public class Memo extends Activity{

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        final Dialog d1 = new Dialog(this);
        Window window = d1.getWindow();
        window.setFlags(WindowManager.LayoutParams.FLAG_BLUR_BEHIND,
                WindowManager.LayoutParams.FLAG_BLUR_BEHIND);

        d1.setTitle("Register Questions");

        d1.setContentView(R.layout.memo);

        Button view = (Button) d1.findViewById(R.id.view);
        view.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v)
            {
                /*Intent intent = new Intent(getBaseContext(), View.class);
                startActivity(intent);*/
            }
    });
}
}

备忘录.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="match_parent">

<TextView android:text="Titile" android:id="@+id/TextView01" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
<EditText android:id="@+id/question" android:layout_width="match_parent" android:layout_height="wrap_content" android:text=""></EditText>
<TextView android:text="Text" android:id="@+id/TextView01" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
<EditText android:minLines="6" android:maxLines="10" android:id="@+id/answer" android:layout_width="match_parent" android:layout_height="wrap_content" android:text=""></EditText>
<TableLayout android:layout_height="wrap_content"
        android:layout_width="wrap_content" android:layout_gravity="center"
        android:stretchColumns="*">
<TableRow>
<Button android:id="@+id/add" android:layout_width="wrap_content" android:text="ADD" android:layout_height="wrap_content"></Button>
<Button android:id="@+id/view" android:layout_width="wrap_content" android:text="VIEW" android:layout_height="wrap_content"></Button>
</TableRow>
</TableLayout>
</LinearLayout>

Answer 1

您还没有为您的对话框调用show()方法。

在方法d1.show()的末尾添加onCreate()