如果我尝试启动我的应用程序，它会失败并显示以下错误:
09-17 20:41:18.190 2063-2063/cz.test.sudoman281.lesnicketabulky E/AndroidRuntime? FATAL EXCEPTION: main
Process: cz.test.sudoman281.lesnicketabulky, PID: 2063
java.lang.NumberFormatException: Invalid int: ""
at java.lang.Integer.invalidInt(Integer.java:138)
at java.lang.Integer.parseInt(Integer.java:358)
at java.lang.Integer.parseInt(Integer.java:334)
at cz.test.sudoman281.lesnicketabulky.MainActivity$1.onFocusChange(MainActivity.java:36)
at android.view.View.onFocusChanged(View.java:5192)
at android.widget.TextView.onFocusChanged(TextView.java:7989)
at android.view.View.handleFocusGainInternal(View.java:4948)
at android.view.View.requestFocusNoSearch(View.java:7547)
at android.view.View.requestFocus(View.java:7526)
at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2557)
at android.view.ViewGroup.requestFocus(ViewGroup.java:2513)
at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2557)
at android.view.ViewGroup.requestFocus(ViewGroup.java:2513)
at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2557)
at android.view.ViewGroup.requestFocus(ViewGroup.java:2513)
at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2557)
at android.view.ViewGroup.requestFocus(ViewGroup.java:2513)
at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2557)
at android.view.ViewGroup.requestFocus(ViewGroup.java:2513)
at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2557)
at android.view.ViewGroup.requestFocus(ViewGroup.java:2516)
at android.view.View.requestFocus(View.java:7493)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1968)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1087)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6040)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:793)
at android.view.Choreographer.doCallbacks(Choreographer.java:606)
at android.view.Choreographer.doFrame(Choreographer.java:575)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:779)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5538)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
我的代码:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button spocitat = (Button) findViewById(R.id.spocitat);
EditText delka = (EditText) findViewById(R.id.delka);
EditText tloustka = (EditText) findViewById(R.id.tloustka);
delka.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
EditText delka = (EditText) findViewById(R.id.delka);
EditText tloustka = (EditText) findViewById(R.id.tloustka);
TextView prumer = (TextView) findViewById(R.id.prumer);
RadioButton smrk = (RadioButton) findViewById(R.id.smrk);
RadioButton borovice = (RadioButton) findViewById(R.id.borovice);
RadioButton boroveOddenky = (RadioButton) findViewById(R.id.oddenky);
RadioButton buk = (RadioButton) findViewById(R.id.buk);
RadioButton dub = (RadioButton) findViewById(R.id.dub);
if (delka != null && tloustka != null) {
int L = Integer.parseInt(delka.getText().toString());
int Dsk = Integer.parseInt(tloustka.getText().toString());
if (smrk.isChecked()) {
double p0 = Math.pow(5.7723 * 10, -1);
double p1 = Math.pow(6.8968 * 10, -3);
double p2 = Math.pow(1.3123 * 10, 0);
double Dp2 = Math.pow(Dsk, p2);
double pi = 3.14159;
double cast1 = Math.pow(Dsk - (p0 + p1 * Dp2), 2);
int vypocet = (int) Math.floor(((cast1 * pi * L) / 40000) * 100);
prumer.setText(String.valueOf(vypocet));
} else if (borovice.isChecked()) {
} else if (boroveOddenky.isChecked()) {
} else if (buk.isChecked()) {
} else if (dub.isChecked()) {
} else {
prumer.setText("Musíte zvolit drevinu!");
}
}
}
});
}
最佳答案
这是因为您尝试解析为整数的字符串在以下两行之一中为空:
int L = Integer.parseInt(delka.getText().toString());
int Dsk = Integer.parseInt(tloustka.getText().toString());
行 if (delka != null && tloustka != null) 无法修复此问题，因为您只检查文本框实例是否不为 null。您还需要验证它们的内容是否不为空。
关于java - 应用程序因 java.lang.NumberFormatException : Invalid int 失败，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/32637876/