TextView 中的整数值不会更新； onClickListener 不会 运行 代码
Integer value in TextView won't update; onClickListener won't run code
无论我为此作业编辑或更改我的 Java 代码多少，它都拒绝正确更新我为结果设置的整数变量的值。有人可以告诉我我在这里到底想念什么吗？下面是我的代码：
包裹 com.example.minicalc；
import com.example.minicalc.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.inputmethod.EditorInfo;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.TextView.OnEditorActionListener;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.util.Log;
public class MainActivity extends Activity implements OnEditorActionListener {
private static final String TAG = "MiniCalc";
private SharedPreferences savedValues;
private EditText editText1;
private EditText editText2;
private Button button1;
private Spinner spinner1;
private TextView answerLbl;
private int ivalue1 = 0;
private int ivalue2 = 0;
private int ianswer;
private int spinChoice;
//private String[] spinner_strings = {"+", "-", "×", "÷"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "onCreate event started");
setContentView(R.layout.activity_main);
spinner1 = (Spinner) findViewById(R.id.spinner1);
button1 = (Button) findViewById(R.id.button1);
answerLbl = (TextView) findViewById(R.id.answerTxt);
editText1 = (EditText) findViewById(R.id.editText1);
editText2 = (EditText) findViewById(R.id.editText2);
editText1.setOnEditorActionListener(this);
editText2.setOnEditorActionListener(this);
savedValues = getSharedPreferences("SavedValues", MODE_PRIVATE);
spinChoice = spinner1.getSelectedItemPosition();
button1.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
Log.d(TAG, "onClick event started");
ianswer = 0;
if (spinChoice == 0) {
ianswer = ivalue1 + ivalue2;
Log.d(TAG, "ianswer VALUE IS: " + Integer.valueOf(ianswer).toString());
} else if (spinChoice == 1) {
ianswer = ivalue1 - ivalue2;
Log.d(TAG, "ianswer VALUE IS: " + Integer.valueOf(ianswer).toString());
} else if (spinChoice == 2) {
ianswer = ivalue1 * ivalue2;
Log.d(TAG, "ianswer VALUE IS: " + Integer.valueOf(ianswer).toString());
} else if (spinChoice == 3) {
ianswer = ivalue1 / ivalue2;
Log.d(TAG, "ianswer VALUE IS: " + Integer.valueOf(ianswer).toString());
}
answerLbl.setText(Integer.toString(ianswer));
//answerLbl.setText(""+ianswer);
Log.d(TAG, "answerLbl TEXT IS: " + answerLbl.getText());
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, 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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
Log.d(TAG, "onEditorAction event started");
if (actionId == EditorInfo.IME_ACTION_DONE || actionId == EditorInfo.IME_ACTION_UNSPECIFIED) {
ivalue1 = Integer.parseInt(editText1.getText().toString());
ivalue2 = Integer.parseInt(editText2.getText().toString());
}
return false;
}
@Override
public void onPause() {
Log.d(TAG, "onPause event started");
Editor editor = savedValues.edit();
editor.putString("value1", editText1.getText().toString());
editor.putString("value2", editText2.getText().toString());
editor.commit();
super.onPause();
}
@Override
public void onResume() {
super.onResume();
Log.d(TAG, "onResume event started");
editText1.setText(savedValues.getString("value1", ""));
editText2.setText(savedValues.getString("value2", ""));
}
}
这是我的布局 XML, activity_main.xml:
<?xml version="1.0" encoding="UTF-8"?>
<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.minicalc.MainActivity" >
<TextView
android:id="@+id/valLbl1"
android:labelFor="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="30dp"
android:layout_marginTop="40dp"
android:text="@string/valueLbl1" />
<TextView
android:id="@+id/valLbl2"
android:labelFor="@+id/editText2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="@+id/valLbl1"
android:layout_below="@+id/editText1"
android:layout_marginTop="24dp"
android:text="@string/valueLbl2" />
<EditText
android:id="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="@+id/valLbl1"
android:layout_below="@+id/valLbl1"
android:layout_marginTop="20dp"
android:ems="5"
android:inputType="number">
<requestFocus />
</EditText>
<EditText
android:id="@+id/editText2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="@+id/valLbl2"
android:layout_below="@+id/valLbl2"
android:layout_marginTop="16dp"
android:ems="5"
android:inputType="number" />
<TextView
android:id="@+id/answerTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/answerLblTxt"
android:layout_centerHorizontal="true"
android:ems="7"/>
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/editText2"
android:layout_centerHorizontal="true"
android:layout_marginTop="18dp"
android:text="@string/submit" />
<TextView
android:id="@+id/answerLblTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="@+id/editText2"
android:layout_below="@+id/button1"
android:layout_marginTop="16dp"
android:text="@string/answerLbl" />
<Spinner
android:id="@+id/spinner1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/valLbl2"
android:layout_marginStart="28dp"
android:layout_toEndOf="@+id/editText2"
android:entries="@array/spinner_strings" />
</RelativeLayout>
现在，应用程序运行正常，LogCat 消息显示正常...除非我将它们放入 onClickListener。所以是的，我已经确定了问题出在哪里，我只是不知道问题出在哪里。我会显示错误的屏幕截图，但这是我第一次发帖。无论如何，phone 我 运行 上的应用程序是 Samsung Galaxy Note 3，运行 Android 4.4.4。谁能帮帮我？
您的微调器 getSelectedItemPoisition() 方法仅在您的 onCreate() 方法中调用一次，并且不会在您每次单击按钮时调用，导致该值永远不会更新。
button1.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
spinChoice = spinner1.getSelectedItemPosition();
...
}
需要在 onClick() 方法中添加这行代码，以便在单击按钮时读取新值。
无论我为此作业编辑或更改我的 Java 代码多少，它都拒绝正确更新我为结果设置的整数变量的值。有人可以告诉我我在这里到底想念什么吗？下面是我的代码： 包裹 com.example.minicalc；
import com.example.minicalc.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.inputmethod.EditorInfo;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.TextView.OnEditorActionListener;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.util.Log;
public class MainActivity extends Activity implements OnEditorActionListener {
private static final String TAG = "MiniCalc";
private SharedPreferences savedValues;
private EditText editText1;
private EditText editText2;
private Button button1;
private Spinner spinner1;
private TextView answerLbl;
private int ivalue1 = 0;
private int ivalue2 = 0;
private int ianswer;
private int spinChoice;
//private String[] spinner_strings = {"+", "-", "×", "÷"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "onCreate event started");
setContentView(R.layout.activity_main);
spinner1 = (Spinner) findViewById(R.id.spinner1);
button1 = (Button) findViewById(R.id.button1);
answerLbl = (TextView) findViewById(R.id.answerTxt);
editText1 = (EditText) findViewById(R.id.editText1);
editText2 = (EditText) findViewById(R.id.editText2);
editText1.setOnEditorActionListener(this);
editText2.setOnEditorActionListener(this);
savedValues = getSharedPreferences("SavedValues", MODE_PRIVATE);
spinChoice = spinner1.getSelectedItemPosition();
button1.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
Log.d(TAG, "onClick event started");
ianswer = 0;
if (spinChoice == 0) {
ianswer = ivalue1 + ivalue2;
Log.d(TAG, "ianswer VALUE IS: " + Integer.valueOf(ianswer).toString());
} else if (spinChoice == 1) {
ianswer = ivalue1 - ivalue2;
Log.d(TAG, "ianswer VALUE IS: " + Integer.valueOf(ianswer).toString());
} else if (spinChoice == 2) {
ianswer = ivalue1 * ivalue2;
Log.d(TAG, "ianswer VALUE IS: " + Integer.valueOf(ianswer).toString());
} else if (spinChoice == 3) {
ianswer = ivalue1 / ivalue2;
Log.d(TAG, "ianswer VALUE IS: " + Integer.valueOf(ianswer).toString());
}
answerLbl.setText(Integer.toString(ianswer));
//answerLbl.setText(""+ianswer);
Log.d(TAG, "answerLbl TEXT IS: " + answerLbl.getText());
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, 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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
Log.d(TAG, "onEditorAction event started");
if (actionId == EditorInfo.IME_ACTION_DONE || actionId == EditorInfo.IME_ACTION_UNSPECIFIED) {
ivalue1 = Integer.parseInt(editText1.getText().toString());
ivalue2 = Integer.parseInt(editText2.getText().toString());
}
return false;
}
@Override
public void onPause() {
Log.d(TAG, "onPause event started");
Editor editor = savedValues.edit();
editor.putString("value1", editText1.getText().toString());
editor.putString("value2", editText2.getText().toString());
editor.commit();
super.onPause();
}
@Override
public void onResume() {
super.onResume();
Log.d(TAG, "onResume event started");
editText1.setText(savedValues.getString("value1", ""));
editText2.setText(savedValues.getString("value2", ""));
}
}
这是我的布局 XML, activity_main.xml:
<?xml version="1.0" encoding="UTF-8"?>
<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.minicalc.MainActivity" >
<TextView
android:id="@+id/valLbl1"
android:labelFor="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="30dp"
android:layout_marginTop="40dp"
android:text="@string/valueLbl1" />
<TextView
android:id="@+id/valLbl2"
android:labelFor="@+id/editText2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="@+id/valLbl1"
android:layout_below="@+id/editText1"
android:layout_marginTop="24dp"
android:text="@string/valueLbl2" />
<EditText
android:id="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="@+id/valLbl1"
android:layout_below="@+id/valLbl1"
android:layout_marginTop="20dp"
android:ems="5"
android:inputType="number">
<requestFocus />
</EditText>
<EditText
android:id="@+id/editText2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="@+id/valLbl2"
android:layout_below="@+id/valLbl2"
android:layout_marginTop="16dp"
android:ems="5"
android:inputType="number" />
<TextView
android:id="@+id/answerTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/answerLblTxt"
android:layout_centerHorizontal="true"
android:ems="7"/>
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/editText2"
android:layout_centerHorizontal="true"
android:layout_marginTop="18dp"
android:text="@string/submit" />
<TextView
android:id="@+id/answerLblTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="@+id/editText2"
android:layout_below="@+id/button1"
android:layout_marginTop="16dp"
android:text="@string/answerLbl" />
<Spinner
android:id="@+id/spinner1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/valLbl2"
android:layout_marginStart="28dp"
android:layout_toEndOf="@+id/editText2"
android:entries="@array/spinner_strings" />
</RelativeLayout>
现在，应用程序运行正常，LogCat 消息显示正常...除非我将它们放入 onClickListener。所以是的，我已经确定了问题出在哪里，我只是不知道问题出在哪里。我会显示错误的屏幕截图，但这是我第一次发帖。无论如何，phone 我 运行 上的应用程序是 Samsung Galaxy Note 3，运行 Android 4.4.4。谁能帮帮我？
您的微调器 getSelectedItemPoisition() 方法仅在您的 onCreate() 方法中调用一次，并且不会在您每次单击按钮时调用，导致该值永远不会更新。
button1.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
spinChoice = spinner1.getSelectedItemPosition();
...
}
需要在 onClick() 方法中添加这行代码，以便在单击按钮时读取新值。