[英]My app keeps crashing when i open it
我在我的板球得分應用程序中添加了 2 個微調器,並且沒有編譯器錯誤但是我的應用程序在開始時一直崩潰。 當我添加第一個微調器時它工作正常,但是當我添加第二個微調器時,應用程序開始崩潰。 請幫忙。
package com.example.visha.cricketcounter;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
private Spinner spinner;
private Spinner spinner2;
EditText text = (EditText)findViewById(R.id.editText);
String value = text.getText().toString();
EditText text2 = (EditText)findViewById(R.id.editText2);
String value2 = text2.getText().toString();
private static final String[]paths = {"15", "20", "30"};
private final String[]paths1 = {value, value2};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
spinner = (Spinner)findViewById(R.id.spinner);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(MainActivity.this,
android.R.layout.simple_spinner_item,paths);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(this);
spinner2 = (Spinner)findViewById(R.id.spinner2);
ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(MainActivity.this,
android.R.layout.simple_spinner_item,paths1);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner2.setAdapter(adapter2);
spinner2.setOnItemSelectedListener(this);
}
@Override
public void onItemSelected(AdapterView<?> parent, View v, int position, long id) {
switch (position) {
case 0:
// Whatever you want to happen when the first item gets selected
break;
case 1:
// Whatever you want to happen when the second item gets selected
break;
case 2:
// Whatever you want to happen when the thrid item gets selected
break;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {}
@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);
}
}
您應該實現OnItemSelectedListener
以訪問 onItemSelected 方法。
你在像setOnItemSelectedListener(this)
this
的方法中傳遞this
意味着你將監聽器的引用作為類傳遞,但你沒有實現監聽器,像下面一樣刺穿OnItemSelectedListener
並嘗試,
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener
您的活動必須實現接口onItemSelectedListener
並覆蓋方法OnNothingSelected
public class MainActivity extends AppCompatActivity implements onItemSelectedListener{
....
然后在主活動中使用鼠標光標讓您的 IDE 自動插入所有缺少的方法實現
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