我想填充一个ListView
使用ArrayAdapter
,我填充从EditText
输入。我的程序似乎编译正常,但在应用程序启动时,它立即崩溃。我怀疑这与我尝试设置列表视图有关。我不确定我正在初始化错误,导致我的应用程序立即崩溃。任何和所有的提示将不胜感激。提前致谢!使用ArrayAdapter生成ListView
这是我对我的ArrayList
和Adapter
的全球声明。
ArrayList<scoreScreen> savedScores = new ArrayList<>();
ScoreAdapter adapter = new ScoreAdapter(this, savedScores);
ListView listView = (ListView) findViewById(R.id.dispScores);
listView.setAdapter(adapter);
我的适配器类别:
private class ScoreAdapter extends ArrayAdapter<scoreScreen> {
private ScoreAdapter(Context context, ArrayList<scoreScreen> scores) {
super(context, 0, scores);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
scoreScreen score1 = getItem(position);
if (convertView == null){
convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_scores, parent, false);
}
TextView holeNum = (TextView) convertView.findViewById(R.id.holeNum);
holeNum.setText(score1.hole);
return convertView;
}
}
我ListView
我onCreate
方法里面。
ListView listview = (ListView) findViewById(R.id.listView1);
listview.setAdapter(adapter);
我假设我的问题是不是我的EditText
输入内部,因为他们是一个OnClickListener
方法里面,但只是柜面我在下面附了。
public View.OnClickListener onClickListener = new View.OnClickListener() {
@Override
public void onClick(View view) {
EditText input1 = (EditText) findViewById(R.id.scorePrompt);
TextView output1 = (TextView) findViewById(R.id.textTotal);
String blankCheck = input1.getText().toString(); //CHANGE INPUT IN scorePrompt TO STRING
switch (view.getId()) {
case R.id.buttTotal:
if (blankCheck.equals("")) {
Toast blankError = Toast.makeText(getApplicationContext(), "YOU CANT SKIP HOLES JERK", Toast.LENGTH_LONG);
blankError.show();
break;
} else {
int num1 = Integer.parseInt(input1.getText().toString()); //Get input from text box
int sum = num1 + score2;
score2 = sum;
output1.setText("Your score is : " + Integer.toString(sum));
//savedScores.add(input1.getText().toString());
scoreScreen addScore = new scoreScreen("Score is" + num1);
adapter.add(addScore);
j++;
input1.setText(""); //Clear input text box
break;
}
case R.id.allScores: //CHANGE THIS TO AN EDIT BUTTON, ADD A HOLE NUMBER COUNTER AT TOP OF SCREEN!!!!!
output1.setText("you messed up");
break;
case R.id.editScore: //Need to set up Save Array before we can edit
//CURRENTLY ONLY DISPLAYS THE LAST NUNMBER IN THE TEXTEDIT, NEED TO SET UP LISTVIEW!!!!!!
for (int i=0; i < j; i++){
// output1.setText(savedScores.get(i));
} break;
}
}
};
onCreate
方法的要求补充说:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/*Button scoresAct = (Button) findViewById(R.id.allScores); //THIS IS TO GO TO ALL SCORES ACTIVITY
scoresAct.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent scoreScreen = new Intent(MainActivity.this, AllScoresAct.class);
startActivity(scoreScreen);
}
});*/
Button sumScores = (Button) findViewById(R.id.buttTotal);
Button saveScores = (Button) findViewById(R.id.allScores);
Button changeScores = (Button) findViewById(R.id.editScore);
sumScores.setOnClickListener(onClickListener);
saveScores.setOnClickListener(onClickListener);
changeScores.setOnClickListener(onClickListener);
ListView listview = (ListView) findViewById(R.id.listView1);
listview.setAdapter(adapter);
}
移动我的适配器和ArrayList到我onCreate
后,我得到一个新的错误。我对空指针做了一些研究,但是我已经初始化了这两个指针。下面是我的logcat,有什么想法?由于
把你的堆栈跟踪带有错误 –
什么是'MainActivity.java'第21行?你不能在onCreate方法之外创建一个新的ScoreAdapter –
这是因为我的适配器是在我的'onCreate'之外声明的。我已经移动它,但现在收到空指针错误,但我不知道为什么,因为我相信我已正确初始化其他一切。 –