我为我和我的 friend 制作了一个简单的投注应用程序。
我按底部的一个按钮来设置出值(value)。之后，如果我赢了，我按我赢，否则我按我输。当我按下“我输了”或“我赢了”时， TextView 会显示赌注的值(value)。我没有任何错误，我不知道为什么当我打开应用程序时它会崩溃。
这是代码:
import android.content.Context;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
int totalMoney= 0;
int betValue = 0;
String savedMoney;
TextView textView = (TextView) findViewById(R.id.textView);
public void clickP(View view){
totalMoney= totalMoney - betValue;
}
public void clickC(View view){
totalMoney= totalMoney + betValue;
}
public void click1(View view){
betValue = 1;
}
public void click2(View view){
betValue = 2;
}
public void click3(View view){
betValue = 3;
}
public void click4(View view){
betValue = 4;
}
public void click5(View view){
betValue = 5;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
savedMoney = textView.getText().toString();
totalMoney = Integer.parseInt(savedbani);
SharedPreferences sharedPreferences = this.getSharedPreferences("com.markusappcompany.baniipemasa", Context.MODE_PRIVATE);
sharedPreferences.edit().putInt("Money", totalMoney).apply();
sharedPreferences.getInt("Money", totalMoney);
textView.setText(totalMoney);
}
}
这是我在 Logcat 中得到的:
05-22 19:54:52.918 20536-20536/com.markusappcompany.baniipemasa E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.markusappcompany.baniipemasa, PID: 20536
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.markusappcompany.baniipemasa/com.markusappcompany.baniipemasa.MainActivity}: android.content.res.Resources$NotFoundException: String resource ID #0x0
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x0
at android.content.res.Resources.getText(Resources.java:338)
at android.widget.TextView.setText(TextView.java:5494)
at com.markusappcompany.baniipemasa.MainActivity.onCreate(MainActivity.java:61)
at android.app.Activity.performCreate(Activity.java:6975)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
这是我的 xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.markusappcompany.baniipemasa.MainActivity">
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="117dp"
android:layout_marginEnd="1dp"
android:layout_marginStart="80dp"
android:layout_marginTop="228dp"
android:text="I LOST"
app:layout_constraintBottom_toTopOf="@+id/button3"
app:layout_constraintEnd_toStartOf="@+id/button2"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="117dp"
android:layout_marginEnd="80dp"
android:layout_marginStart="1dp"
android:layout_marginTop="228dp"
android:text="I WIN"
app:layout_constraintBottom_toTopOf="@+id/button4"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/button"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="44dp"
android:layout_marginBottom="70dp"
android:layout_marginStart="16dp"
android:text="1 EUR"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/button4"
app:layout_constraintStart_toStartOf="parent" />
<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="70dp"
android:layout_marginTop="117dp"
android:text="2 EUR"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/button5"
app:layout_constraintStart_toEndOf="@+id/button3"
app:layout_constraintTop_toBottomOf="@+id/button" />
<Button
android:id="@+id/button5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="70dp"
android:layout_marginTop="117dp"
android:text="3 EUR"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/button6"
app:layout_constraintStart_toEndOf="@+id/button4"
app:layout_constraintTop_toBottomOf="@+id/button2" />
<Button
android:id="@+id/button6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="70dp"
android:layout_marginEnd="16dp"
android:layout_marginTop="117dp"
android:text="4 LEI"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/button5"
app:layout_constraintTop_toBottomOf="@+id/button2" />
<Button
android:id="@+id/button7"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="20dp"
android:layout_marginEnd="148dp"
android:layout_marginStart="148dp"
android:text="5 LEI"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="163dp"
android:layout_marginEnd="221dp"
android:layout_marginStart="190dp"
android:layout_marginTop="16dp"
android:text="0"
android:textSize="36sp"
android:textStyle="bold"
app:layout_constraintBottom_toTopOf="@+id/button"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.487"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0" />
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="16dp"
android:layout_marginTop="25dp"
android:text="Total money:"
android:textSize="24sp"
app:layout_constraintEnd_toStartOf="@+id/textView"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
提前致谢!
最佳答案
首先，删除所有点击方法，您的 Activity 应如下所示:
public class MainActivity extends AppCompatActivity {
int totalMoney= 0;
int betValue = 0;
String savedMoney;
TextView textView
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.textView);
Button yourButton = findViewById(R.layout.yourButtonId)
Button yourButton2 = findViewById(R.layout.yourButtonId2)
// for all Buttons
}}
您还必须在 Activity_main 文件中为按钮指定一个 ID。之后，您必须为所有这些按钮实现一个 onClickListener，如下所示:
yourButton1.setOnClickListener(this);
// the same for every Button
然后添加这一行:
public class MainActivity extends AppCompatActivity implements View.OnClickListener
最后监听者:
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.yourButtonID:
// when button with this ID is clicked do your stuff here
case R.id.otherButtonID:
// when button with this ID is clicked do your stuff here
}
}
这里的解释是，首先您找到按钮和 textView，然后设置一个 onclicklistener，以便当您单击一个按钮时，该按钮会调用 onClick 方法。 switch 语句被称为找出哪个按钮被调用。
关于java - 当我运行简单的 android studio 应用程序时，它崩溃了。它没有错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/61955330/