Android 字符串[]返回空值

我有4个字符串数组，我正在将其转换为单个字符串（以、）并保存在SharedPreference中。然后，我在onCreate方法中检索变量。然后我想检查元素是否有赋值，如果有，用静态生成的textview显示：

public class DebtList extends Activity {

@TargetApi(Build.VERSION_CODES.HONEYCOMB)
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.debtlist);

    String[] debtName = new String[10];
    String[] debtAmount = new String[10];
    String[] debtRate = new String[10];
    String[] debtPayment = new String[10];

    SharedPreferences sharedPref= getSharedPreferences("chaosdatasnowball", 0);

    String tempDebtNames = sharedPref.getString("debtNames", "");
    if (!tempDebtNames.equals("")){
    debtName = convertStringToArray(tempDebtNames);
    }
    String tempDebtAmounts = sharedPref.getString("debtAmounts", "");
    if (!tempDebtAmounts.equals("")){
    debtName = convertStringToArray(tempDebtAmounts);
    }
    String tempDebtRates = sharedPref.getString("debtRates", "");
    if (!tempDebtRates.equals("")){
    debtName = convertStringToArray(tempDebtRates);
    }
    String tempDebtPayments = sharedPref.getString("debtPayments", "");
    if (!tempDebtPayments.equals("")){
    debtName = convertStringToArray(tempDebtPayments);
    }

    Bundle extras = getIntent().getExtras();

    int trigger = 0;
    for (int i=0;i<debtName.length;i++)
    {
        if (debtName[i] == null && extras != null && trigger == 0)
        {
            debtName[i] = extras.getString("debtName");
            debtAmount[i] = extras.getString("debtAmount");
            debtRate[i] = extras.getString("debtRate");
            debtPayment[i] = extras.getString("debtPayment");
            trigger = 1;
        }
    }

    TableLayout tl = (TableLayout) findViewById(R.id.debtListTableView);
    for (int i=0;i<debtName.length;i++)
    {
        if (debtName[i] != null)
        {

            TableRow tr = new TableRow(this);
            TextView tv0 = new TextView(this);
            TextView tv1 = new TextView(this);
            TextView tv2 = new TextView(this);
            TextView tv3 = new TextView(this);
            TableRow.LayoutParams trlp = new TableRow.LayoutParams();
            tv0.setLayoutParams(new LayoutParams(0, LayoutParams.MATCH_PARENT, 0.25f));
            tv1.setLayoutParams(new LayoutParams(0, LayoutParams.MATCH_PARENT, 0.25f));
            tv2.setLayoutParams(new LayoutParams(0, LayoutParams.MATCH_PARENT, 0.25f));
            tv3.setLayoutParams(new LayoutParams(0, LayoutParams.MATCH_PARENT, 0.25f));
            trlp.span = 3;
            tr.setLayoutParams(trlp);
            tv0.setText("" + debtName[i]);
            tv1.setText("" + debtAmount[i]);
            tv2.setText("" + debtPayment[i]);
            tv3.setText("" + i);
            tr.addView(tv0);
            tr.addView(tv1);
            tr.addView(tv2);
            tr.addView(tv3);
            tl.addView(tr);
        }
    }

    int counter = debtName.length;

    SharedPreferences.Editor editor= sharedPref.edit();
    String debtNames = convertArrayToString(debtName, counter);
    editor.putString("debtNames", debtNames);

    String debtAmounts = convertArrayToString(debtAmount, counter);
    editor.putString("debtAmounts", debtAmounts);

    String debtRates = convertArrayToString(debtRate, counter);
    editor.putString("debtRates", debtRates);

    String debtPayments = convertArrayToString(debtPayment, counter);
    editor.putString("debtPayments", debtPayments);




    editor.putInt("counter", counter);
    editor.commit();

    TextView disp = (TextView) findViewById(R.id.dispAdditionalAmount);
    disp.setText("" + debtNames);


}


public static String convertArrayToString(String[] array, int stop){
    String str = "";
    for (int i = 0;i<stop; i++) {
        str = str+array[i];
        // Do not append comma at the end of last element
        if(i<stop-1){
            str = str+",";
        }
    }
    return str;
}
public static String[] convertStringToArray(String str){
    String[] arr = str.split(",");
    return arr;
}

公共类债务列表扩展活动{
@TargetApi（构建版本代码蜂窝）
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.debtlist）；
字符串[]债务人名称=新字符串[10]；
字符串[]债务金额=新字符串[10]；
字符串[]债务率=新字符串[10]；
字符串[]债务人付款=新字符串[10]；
SharedReferences SharedReferences=GetSharedReferences（“chaosdatasnowball”，0）；
String tempDebtNames=sharedPref.getString（“债务人名称”和“”）；
如果（！tempDebtNames.equals（“”）{
debtName=convertStringToArray（tempDebtName）；
}
String tempDebtAmounts=sharedPref.getString（“debtAmounts”和“”）；
如果（！tempDebtAmounts.equals（“”）{
debtName=convertStringToArray（临时债务金额）；
}
String tempDebtRates=sharedPref.getString（“debtRates”，”）；
如果（！tempDebtRates.equals（“”）{
debtName=convertStringToArray（临时债务利率）；
}
字符串tempDebtPayments=sharedPref.getString（“debtPayments”和“”）；
如果（！tempDebtPayments.equals（“”）{
债务人名称=convertStringToArray（临时债务付款）；
}
Bundle extras=getIntent（）.getExtras（）；
int触发器=0；
对于（int i=0；i可能是因为您没有设置活动的ContentView。请确保您的首选项没有返回null。声明内容视图时，它只是没有复制到此处-更新以显示完整的活动还解释哪些行返回null。@JoxTraex-当“tv0.setText（“+debtName[i]）正在处理中，它在4列10行中显示“null”。