我制作的应用程序在您选择最小和最大数字后显示随机数。但是旋转结果消失后,所以我实现了 onSaveInstanceState 并根据我的需要定制了它,之后我的应用程序一直崩溃。
公共(public)类 MainActivity 扩展 AppCompatActivity {
EditText et_min,et_max;
Button button;
TextView tv_output;
Random r;
int min, max, output;
private static final String STATE_TV_OUTPUT = "tv_output";
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
String onSave = savedInstanceState.getString("onSave");
}
@Override
protected void onSaveInstanceState(Bundle SavedInstanceState) {
super.onSaveInstanceState(SavedInstanceState);
SavedInstanceState.putString("onSave", "1");
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
r = new Random();
String onSave = tv_output.getText().toString();
et_max = (EditText) findViewById(R.id.et_max);
et_min = (EditText) findViewById(R.id.et_min);
button = (Button) findViewById(R.id.button);
tv_output = (TextView) findViewById(R.id.tv_output);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String tempMin, tempMax;
tempMin = et_min.getText().toString();
tempMax = et_max.getText().toString();
if (!tempMin.equals("") && !tempMax.equals(""))//ovde stavljam ih u poziciju gde su slobodni za pisanje
min = Integer.parseInt(tempMin);
max = Integer.parseInt(tempMax);//ova dva sluze kako bi pretvorili stringove u intove za potrebe dole methoda
if (max > min) {
output = r.nextInt((max - min) + 1) + min;//nextInt sluzi kako bi dao random broj izmedju dva broja u ovom slucaju min i max
tv_output.setText("" + output);
}
}
});
}
}
最佳答案
您需要更改顺序,否则更改后的 bundle 将不会被传递:
@Override
protected void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putString("onSave", "1");
super.onSaveInstanceState(savedInstanceState);
}
对super
类方法的调用并不总是最顶层的。
关于java - 实现 onSaveInstanceState 并自定义它以在旋转屏幕后保存文本后应用程序崩溃,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/54508148/