Java 为什么我的应用程序在没有任何错误的情况下崩溃?
应用程序崩溃,我收到以下错误:Java 为什么我的应用程序在没有任何错误的情况下崩溃?,java,android,runtimeexception,Java,Android,Runtimeexception,应用程序崩溃,我收到以下错误: 致命异常:主 进程:com.example.ayyan.jellybeanstimator,PID:2960 java.lang.RuntimeException:无法启动活动 ComponentInfo{com.example.ayyan.jellybeanstimator/com.example.ayyan.jellybeanstimator.MainActivity}: java.lang.NumberFormatException:空字符串 在 andr
致命异常:主 进程:com.example.ayyan.jellybeanstimator,PID:2960 java.lang.RuntimeException:无法启动活动 ComponentInfo{com.example.ayyan.jellybeanstimator/com.example.ayyan.jellybeanstimator.MainActivity}: java.lang.NumberFormatException:空字符串 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646) 在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 位于android.app.ActivityThread.-wrap12(ActivityThread.java) 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 位于android.os.Handler.dispatchMessage(Handler.java:102) 位于android.os.Looper.loop(Looper.java:154) 位于android.app.ActivityThread.main(ActivityThread.java:6077) 位于java.lang.reflect.Method.invoke(本机方法) 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 原因:java.lang.NumberFormatException:空字符串 在 java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1071) 位于java.lang.Double.parseDouble(Double.java:547) 在 com.example.ayyan.jellybeanestimator.MainActivity.onCreate(MainActivity.java:25) 位于android.app.Activity.performCreate(Activity.java:6662) 在 android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599) 在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 位于android.app.ActivityThread.-wrap12(ActivityThread.java) 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 位于android.os.Handler.dispatchMessage(Handler.java:102) 位于android.os.Looper.loop(Looper.java:154) 位于android.app.ActivityThread.main(ActivityThread.java:6077) 位于java.lang.reflect.Method.invoke(本机方法) 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
您应该计算一下按钮的点击次数。在您的代码中,您并没有输入任何值并试图计算它
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
jellyBeanLength = (EditText) findViewById (R.id.length);
jellyBeanDiameter = (EditText) findViewById (R.id.diameter);
jarSizeVolume = (EditText) findViewById (R.id.jarsize);
jellybeantall = Double.parseDouble(jellyBeanLength.getText().toString());
jellybeanfat = Double.parseDouble(jellyBeanDiameter.getText().toString());
jellybeanspace = Double.parseDouble(jarSizeVolume.getText().toString());
answer = (TextView) findViewById (R.id.answer);
Button calculate = (Button) findViewById (R.id.calculate);
calculate.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
double volumeOfOneJellyBean = ((3.14159265359/6)*(jellybeanfat*jellybeanfat)*jellybeantall);
double volumeofBeans = (jellybeanspace*loadFactor);
float numberOfBeans = (float)Math.round (volumeofBeans/volumeOfOneJellyBean);
answer.setText("You have this amount of beans in your jar" + numberOfBeans);
}
});
}
您应该计算一下按钮的点击次数。在您的代码中,您并没有输入任何值并试图计算它
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
jellyBeanLength = (EditText) findViewById (R.id.length);
jellyBeanDiameter = (EditText) findViewById (R.id.diameter);
jarSizeVolume = (EditText) findViewById (R.id.jarsize);
jellybeantall = Double.parseDouble(jellyBeanLength.getText().toString());
jellybeanfat = Double.parseDouble(jellyBeanDiameter.getText().toString());
jellybeanspace = Double.parseDouble(jarSizeVolume.getText().toString());
answer = (TextView) findViewById (R.id.answer);
Button calculate = (Button) findViewById (R.id.calculate);
calculate.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
double volumeOfOneJellyBean = ((3.14159265359/6)*(jellybeanfat*jellybeanfat)*jellybeantall);
double volumeofBeans = (jellybeanspace*loadFactor);
float numberOfBeans = (float)Math.round (volumeofBeans/volumeOfOneJellyBean);
answer.setText("You have this amount of beans in your jar" + numberOfBeans);
}
});
}
EditText字段中没有值,您正在尝试分析该值。因此出现错误java.lang.NumberFormatException:空字符串。EditText字段中没有值,您正在尝试分析该值。因此出现错误java.lang.NumberFormatException:空字符串。请检查是否在
EditText
然后只在Double
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
jellyBeanLength = (EditText) findViewById (R.id.length);
jellyBeanDiameter = (EditText) findViewById (R.id.diameter);
jarSizeVolume = (EditText) findViewById (R.id.jarsize);
answer = (TextView) findViewById (R.id.answer);
Button calculate = (Button) findViewById (R.id.calculate);
calculate.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//Take out value when button pressed
jellybeantall = Double.parseDouble(TextUtils.isEmpty(jellyBeanLength.getText().toString())?"0":jellyBeanLength.getText().toString());
jellybeanfat = Double.parseDouble(TextUtils.isEmpty(jellyBeanDiameter.getText().toString())?"0":jellyBeanDiameter.getText().toString());
jellybeanspace = Double.parseDouble(TextUtils.isEmpty(jarSizeVolume.getText().toString())?"0":jarSizeVolume.getText().toString());
double volumeOfOneJellyBean = ((3.14159265359/6)*(jellybeanfat*jellybeanfat)*jellybeantall);
double volumeofBeans = (jellybeanspace*loadFactor);
float numberOfBeans = (float)Math.round (volumeofBeans/volumeOfOneJellyBean);
answer.setText("You have this amount of beans in your jar" + numberOfBeans);
}
});
}
检查是否在
EditText
中插入了任何值,然后仅在Double
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
jellyBeanLength = (EditText) findViewById (R.id.length);
jellyBeanDiameter = (EditText) findViewById (R.id.diameter);
jarSizeVolume = (EditText) findViewById (R.id.jarsize);
answer = (TextView) findViewById (R.id.answer);
Button calculate = (Button) findViewById (R.id.calculate);
calculate.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//Take out value when button pressed
jellybeantall = Double.parseDouble(TextUtils.isEmpty(jellyBeanLength.getText().toString())?"0":jellyBeanLength.getText().toString());
jellybeanfat = Double.parseDouble(TextUtils.isEmpty(jellyBeanDiameter.getText().toString())?"0":jellyBeanDiameter.getText().toString());
jellybeanspace = Double.parseDouble(TextUtils.isEmpty(jarSizeVolume.getText().toString())?"0":jarSizeVolume.getText().toString());
double volumeOfOneJellyBean = ((3.14159265359/6)*(jellybeanfat*jellybeanfat)*jellybeantall);
double volumeofBeans = (jellybeanspace*loadFactor);
float numberOfBeans = (float)Math.round (volumeofBeans/volumeOfOneJellyBean);
answer.setText("You have this amount of beans in your jar" + numberOfBeans);
}
});
}
您可以尝试更改:
answer.setText(“你的罐子里有这么多的豆子”+numberOfBeans)代码>
到
answer.setText(“您的jar中有这么多的bean”+String.valueOf(numberOfBeans))代码>
这将把双精度转换为字符串。您可以尝试更改:
answer.setText(“你的罐子里有这么多的豆子”+numberOfBeans)代码>
到
answer.setText(“您的jar中有这么多的bean”+String.valueOf(numberOfBeans))