Java Android Studio代码不工作?
我有一些我在安卓工作室工作的代码。我们的目标是创建一个应用程序,当你按下开始按钮时,计数器会快速上升,当它达到所需输入时,你按下停止按钮,它会记录你离所需值的距离。这是为了测试反应时间等等。问题是,每当我在手机或模拟器上运行应用程序时,应用程序都会立即崩溃,并出现错误“很遗憾,计时器测试已停止工作”。有人知道可能是什么问题吗 MainActivity.java中的代码:Java Android Studio代码不工作?,java,android,android-studio,Java,Android,Android Studio,我有一些我在安卓工作室工作的代码。我们的目标是创建一个应用程序,当你按下开始按钮时,计数器会快速上升,当它达到所需输入时,你按下停止按钮,它会记录你离所需值的距离。这是为了测试反应时间等等。问题是,每当我在手机或模拟器上运行应用程序时,应用程序都会立即崩溃,并出现错误“很遗憾,计时器测试已停止工作”。有人知道可能是什么问题吗 MainActivity.java中的代码: package com.ultraman11.timertest; import android.support.v7.ap
package com.ultraman11.timertest;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
public int numCounter = 0;
public boolean counting = false;
TextView counter = (TextView) findViewById(R.id.counter);
TextView difference = (TextView) findViewById(R.id.diff);
EditText numInput = (EditText) findViewById(R.id.numInput);
public int userInt = Integer.parseInt(numInput.getText().toString());
public int differenceInt = Math.abs(numCounter - userInt);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void resetButton(View v){
numCounter = 0;
difference.setText("Difference: ");
counter.setText(Integer.toString(0));
}
public void startButton(View v){
counting = true;
while(counting){
numCounter++;
}
}
public void stopButton(View v){
counting = false;
difference.setText("Difference: " + Integer.toString(differenceInt));
}
@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, 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);
}
}
activity_main.xml中的代码
<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=".MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Reset"
android:id="@+id/button"
android:nestedScrollingEnabled="false"
android:onClick="resetButton"
android:layout_below="@+id/numInput"
android:layout_centerHorizontal="true"
android:layout_marginTop="38dp" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Start"
android:id="@+id/button2"
android:onClick="startButton"
android:layout_below="@+id/numInput"
android:layout_alignLeft="@+id/button"
android:layout_alignStart="@+id/button"
android:layout_marginTop="112dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="0"
android:id="@+id/counter"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="79dp" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/numInput"
android:inputType="number"
android:layout_below="@+id/counter"
android:layout_alignLeft="@+id/button"
android:layout_alignStart="@+id/button"
android:layout_marginTop="31dp"
android:layout_alignRight="@+id/button"
android:layout_alignEnd="@+id/button" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Stop"
android:id="@+id/button3"
android:layout_marginTop="23dp"
android:layout_below="@+id/button2"
android:layout_alignLeft="@+id/button2"
android:layout_alignStart="@+id/button2"
android:onClick="stopButton" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Difference: "
android:id="@+id/diff"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="43dp" />
</RelativeLayout>
当你点击开始时,你会立即进入一个循环,因为计数是真的,所以它只是将numCounter增加到infty。 而不是围绕增量的东西,而使用类似异步任务的东西来增加您的价值 编辑:
很抱歉,我没有意识到它会立即崩溃,请确保在调用onCreate之前先在onCreate方法中初始化内容。。。setContentView()在调用
onCreate()
之前,不能使用findViewById()
。您需要更改:
TextView counter;
TextView difference;
EditText numInput;
并在onCreate()
中设置它们:
您必须在活动的onCreate()方法中初始化视图。我已经编辑了您的java文件。试试这个
package com.ultraman11.timertest;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
public int numCounter = 0;
public boolean counting = false;
TextView counter;
TextView difference;
EditText numInput;
public int userInt
public int differenceInt;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
counter = (TextView) findViewById(R.id.counter);
difference = (TextView) findViewById(R.id.diff);
numInput = (EditText) findViewById(R.id.numInput);
try{
userInt = Integer.parseInt(numInput.getText().toString());
}Catch(Exception e){
userInt = 0;
}
differenceInt = Math.abs(numCounter - userInt);
}
public void resetButton(View v){
numCounter = 0;
difference.setText("Difference: ");
counter.setText(Integer.toString(0));
}
public void startButton(View v){
counting = true;
while(counting){
numCounter++;
}
}
public void stopButton(View v){
counting = false;
difference.setText("Difference: " + Integer.toString(differenceInt));
}
@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, 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);
}
}
更新代码
package com.ultraman11.timertest;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
public int numCounter = 0;
public boolean counting = false;
TextView counter;
TextView difference;
EditText numInput;
public int userInt;
public int differenceInt;
TimerTask timertask = null;
Timer timer = null ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
counter = (TextView) findViewById(R.id.counter);
difference = (TextView) findViewById(R.id.diff);
numInput = (EditText) findViewById(R.id.numInput);
}
public void resetButton(View v){
numCounter = 0;
difference.setText("Difference: ");
counter.setText(Integer.toString(0));
if(timertask!=null){
timertask.cancel();
timertask = null;
}
if(timer!=null){
timer.cancel();
timer = null;
}
}
public void startButton(View v){
if(timertask!=null){
timertask.cancel();
timertask = null;
}
if(timer!=null){
timer.cancel();
timer = null;
}
timer = new Timer();
timertask = new TimerTask() {
@Override
public void run() {
numCounter++;
runOnUiThread(new Runnable() {
public void run() {
counter.setText(Integer.toString(numCounter));
}
});
}
};
timer.scheduleAtFixedRate(timertask, 0, 1000);
}
public void stopButton(View v){
if(timertask!=null){
timertask.cancel();
timertask = null;
}
if(timer!=null){
timer.cancel();
timer = null;
}
try{
userInt = Integer.parseInt(numInput.getText().toString());
}catch(Exception e){
userInt = 0;
}
differenceInt = Math.abs(numCounter - userInt);
difference.setText("Difference: " + Integer.toString(differenceInt));
}
@Override
protected void onDestroy() {
if(timertask!=null){
timertask.cancel();
timertask = null;
}
if(timer!=null){
timer.cancel();
timer = null;
}
super.onDestroy();
}
}
这是很多人犯的一个简单错误。查看LogCat,它告诉您需要使用Theme.AppCompat或类似的工具。AppCompat需要AppCompat。它与设备主题不兼容。 您只需打开AndroidManifest.xml并执行以下操作:
<application
...
android:theme="@style/AppTheme">
...
</application>
...
并在/res/values/styles.xml中添加以下内容:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="AppBaseTheme" parent="Theme.AppCompat"/>
<style name="AppTheme" parent="AppBaseTheme">
<!-- Put any customizations here. -->
</style>
</resources>
请从Logcat提供堆栈跟踪如果没有堆栈跟踪,我们只能扫描您的代码并尝试找出问题所在。请帮助我们,通过发布stacktrace和相关信息来帮助您。这有助于我们更容易地帮助您。我在开始时将计数设置为false。即使我还没有按下按钮函数,它是否会从按钮函数设置为true?真正的问题是如何初始化视图,如编辑中所述。在onCreate()方法中初始化我的内容时,其他代码都不起作用,因为找不到该值。(我指的内容是文本和编辑视图。)初始化userInt和differenceInt也在onCreate方法中,它应该可以工作,因为在调用onCreate之前,您的内容不可见。刚刚用我使用您编辑的代码得到的logcat错误更新了主帖。代码现在可以工作,应用程序运行。我只是尝试添加counter.setText(Integer.toString(numCounter));在numCounter++的右下方;要更新活动计数器,但在它增加到1后,它会立即崩溃。知道为什么吗?runOnUiThread(new Runnable(){public void run(){counter.setText(Integer.toString(numCounter));})代码>将其添加到numCounter++下;非常感谢你!我只是想问我是否应该使用可运行的xD。你帮了我很大的忙。我投了更高的票,只是因为我是新用户,所以没有显示出来。
<application
...
android:theme="@style/AppTheme">
...
</application>
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="AppBaseTheme" parent="Theme.AppCompat"/>
<style name="AppTheme" parent="AppBaseTheme">
<!-- Put any customizations here. -->
</style>
</resources>