java - 按下后退按钮时 Activity 布局的问题

Question

我有这个 Activity 与 EditViews 和按钮。按下按钮后，我将继续进行一项新 Activity 。问题是按下后退按钮时。 EditViews 不可见。预期的是输入的 View 和文本是可见的。此外，出现的按钮来自第二个 Activity ，而不是第一个。

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.ammar.android.dailyjobsiteinspection2.MainActivity1Activity">

<ScrollView
android:layout_width="fill_parent"
android:layout_height="350dp"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
android:id="@+id/scrollView">

<LinearLayout
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true"
    android:id="@+id/linearLayout">

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:text="New Text"
        android:id="@+id/textView"
        android:layout_gravity="center_horizontal"
        android:layout_weight="1"
        android:visibility="invisible" />

    <EditText
        android:layout_width="fill_parent"
        android:layout_height="70dp"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:id="@+id/editText"
        android:layout_gravity="center"
        android:hint="Inspector ID"
        />

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:text="New Text"
        android:id="@+id/textView2"
        android:layout_gravity="center_horizontal"
        android:layout_weight="1"
        android:visibility="invisible" />

    <EditText
        android:layout_width="fill_parent"
        android:layout_height="70dp"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:id="@+id/editText2"
        android:layout_gravity="center"
        android:hint="Site Name" />

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:text="New Text"
        android:id="@+id/textView3"
        android:layout_gravity="center_horizontal"
        android:visibility="invisible"
        android:layout_weight="1" />

    <EditText
        android:layout_width="fill_parent"
        android:layout_height="70dp"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:id="@+id/editText3"
        android:layout_gravity="center"
        android:hint="Site Address" />

    <Button
        android:layout_width="160dp"
        android:layout_height="60dp"
        android:text="Start"
        android:id="@+id/button3"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_gravity="center_horizontal"
        android:onClick="start"
        android:layout_margin="5dp" />
</LinearLayout>
</ScrollView>

</RelativeLayout>

Java代码如下:

    import android.content.Intent;
    import android.support.v7.app.ActionBarActivity;
    import android.os.Bundle;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.widget.EditText;

    public class MainActivity1Activity extends ActionBarActivity {


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main_activity1);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main_activity1, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

public void start(View view){
    EditText editText1 = (EditText) findViewById(R.id.editText);
    EditText editText2 = (EditText) findViewById(R.id.editText2);
    EditText editText3 = (EditText) findViewById(R.id.editText3);

    if(!allFieldsEntered(editText1, editText2, editText3)){
        com.ammar.android.dailyjobsiteinspection2.Message.message(this, "All fields must be filled before starting an Audit ");
    }else{
        Intent intent = new Intent(this, MainActivity11Activity.class);
        Bundle bundle = getDataBundle(editText1, editText2, editText3);
        intent.putExtras(bundle);
        setContentView(R.layout.activity_main_activity11);
        startActivity(intent);
    }
}

private Bundle getDataBundle(EditText editText1, EditText editText2, EditText editText3) {
    Bundle bundle = new Bundle();
    bundle.putString(MainActivity.INSPECTORID, editText1.getText().toString());
    bundle.putString(MainActivity.SITENAME, editText2.getText().toString());
    bundle.putString(MainActivity.SITEADDRESS, editText3.getText().toString());
    return bundle;
}

private boolean allFieldsEntered(EditText editText1, EditText editText2, EditText editText3) {
    return !(editText1.getText().toString().matches("")
            || editText2.getText().toString().matches("")
            || editText3.getText().toString().matches(""));
}
}

这是第二个 Activity :

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context="com.ammar.android.dailyjobsiteinspection2.MainActivity11Activity">


<ScrollView
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:id="@+id/scrollView"
    android:layout_gravity="center_horizontal"
    android:layout_weight="1">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/layout"></LinearLayout>
</ScrollView>

<LinearLayout
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:id="@+id/layout2">
    android:layout_gravity="center_horizontal">

    <TextView
        android:layout_width="0dp"
        android:layout_height="fill_parent"
        android:text="New Text"
        android:id="@+id/textView4"
        android:layout_weight="1"
        android:visibility="invisible" />

    <Button
        android:layout_width="160dp"
        android:layout_height="fill_parent"
        android:text="Save"
        android:id="@+id/button4"
        android:onClick="save" />

    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="New Text"
        android:id="@+id/textView5"
        android:layout_weight="1"
        android:visibility="invisible"/>

    <Button
        android:layout_width="160dp"
        android:layout_height="fill_parent"
        android:text="Submit"
        android:id="@+id/button5"
        android:onClick="submit" />

    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="New Text"
        android:id="@+id/textView6"
        android:layout_weight="1"
        android:visibility="invisible"/>
</LinearLayout>

</LinearLayout>

和 Java 代码:

    import android.app.ActionBar;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Typeface;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.text.Layout;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
import java.util.ArrayList;


public class MainActivity11Activity extends ActionBarActivity {

private ArrayList<RadioGroup> radioGroupArrayList;
private String inspectorId;
private String siteName;
private String siteAddress;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main_activity11);
    setFields();
    setUI();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main_activity11, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

private void setFields() {
    Intent intentBundle = getIntent();                          // get intent
    Bundle bundle = intentBundle.getExtras();                   // get bundle from intent
    inspectorId = bundle.getString(MainActivity.INSPECTORID);
    siteName = bundle.getString(MainActivity.SITENAME);
    siteAddress = bundle.getString(MainActivity.SITEADDRESS);
}

private void setUI() {
    TextView textView;
    radioGroupArrayList = new ArrayList<RadioGroup>();
    LinearLayout ll = (LinearLayout) this.findViewById(R.id.layout);
    int count = 0;
    for(int i = 0; i<6; i++){
        int id = getResources().getIdentifier("PreStart"+ i, "array"  , getPackageName());
        String [] questions = getResources().getStringArray(id);
        textView = new TextView(this);
        textView.setText(questions[0]);
        textView.setTextSize(24);
        textView.setTypeface(null, Typeface.BOLD);
        ll.addView(textView);
        TextView textView1;
        TextView textView2;
        RadioGroup radioGroup;
        RadioButton radioButton1;
        RadioButton radioButton2;
        RadioButton radioButton3;
        for (int j = 1; j< questions.length; j++){
            textView1 = new TextView(this);
            textView1.setText(questions[j]);
            textView1.setTextSize(18);

            radioGroup = new RadioGroup(this);
            radioGroupArrayList.add(radioGroup);
            radioButton1 = new RadioButton(this);
            radioButton2 = new RadioButton(this);
            radioButton3 = new RadioButton(this);
            radioButton1.setText("Yes");
            radioButton2.setText("No");
            radioButton3.setText("NA");
            radioButton1.setId(count);
            radioButton2.setId(count+1);
            radioButton3.setId(count+2);
            count = count + 3;
            radioGroup.addView(radioButton1);
            radioGroup.addView(radioButton2);
            radioGroup.addView(radioButton3);
            radioButton1.setPadding(20, 20, 100, 20);
            radioButton2.setPadding(20, 20, 100, 20);
            radioButton3.setPadding(20, 20, 100, 20);
            radioGroup.setOrientation(LinearLayout.HORIZONTAL);



            textView2 = new TextView(this);
            textView2.setVisibility(View.INVISIBLE);
            ll.addView(textView1);
            ll.addView(radioGroup);
            ll.addView(textView2);
        }
    }
    EditText editText = new EditText(this);
    editText.setId(R.id.editText11);
    editText.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.WRAP_CONTENT));
    editText.setHint("Enter Comments Here");
    ll.addView(editText);
}


public void save(View view){

    AnswerListCreator answerCreator = new AnswerListCreator(radioGroupArrayList);
    String[] answerList = answerCreator.getAnswerList();
    String commentLog = ((EditText) findViewById(R.id.editText11)).getText().toString();
    DBHelper dbHelper = new DBHelper(this);
    SQLiteDatabase db = dbHelper.getWritableDatabase();
    Site site = new Site(inspectorId, siteName, siteAddress, answerList, commentLog, 0);
    dbHelper.insertSite(db, site);

    // go back to main
    Intent intent = new Intent(this, MainActivity.class);
    setContentView(R.layout.activity_main);
    startActivity(intent);
    db.close();
    finish();
}

public void submit(View view) {

    AnswerListCreator answerCreator = new AnswerListCreator(radioGroupArrayList);
    if (!answerCreator.isComplete()) {
        com.ammar.android.dailyjobsiteinspection2.Message.message(this, "All fields must be checked");
    } else {
        answerCreator = new AnswerListCreator(radioGroupArrayList);
        String[] answerList = answerCreator.getAnswerList();
        String commentLog = ((EditText) findViewById(R.id.editText11)).getText().toString();
        DBHelper dbHelper = new DBHelper(this);
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        Site site = new Site(inspectorId, siteName, siteAddress, answerList, commentLog, 1);
        dbHelper.insertSite(db, site);

        // go back to main
        Intent intent = new Intent(this, MainActivity.class);
        setContentView(R.layout.activity_main);
        startActivity(intent);
        db.close();
        finish();
    }
}
}

Answer 1

在调用 StartActivity 之前，您首先要更改 Activity 的 View 。

在 MainActivity1Activity 中删除它: setContentView(R.layout.activity_main_activity11);

此外，如果您想在 MainActivity1Activity 中保留 View 状态，请不要再次启动它。只需在第二个 Activity 中调用 finish()。