Question

伙计我收到错误，我不知道如何解决，请帮助我。

这是我的代码：

package com.appschool.www.projectphase1516;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.Switch;
import android.widget.TextView;

import com.appschool.www.projectphase1516.R;

import org.w3c.dom.Text;

public class AccountlistActivity extends Activity implements View.OnClickListener {
    LinearLayout horiz;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_accountlist);
        horiz = (LinearLayout) findViewById(R.id.linearlayouthere);
        Accountlistcreator();
        setContentView(horiz);
    }

    public void Accountlistcreator(){
        SharedPreferences sp = getSharedPreferences("details",1);
        int numofaccounts = sp.getInt("numofaccouns",0);
        horiz.removeAllViews();
        for(int i=0;i<=numofaccounts;i++) {
            TextView titleaccount = new TextView(this);
            titleaccount.setText(sp.getString("accountTitle" + i, ""));
            titleaccount.setTextSize(20);
            horiz.addView(titleaccount);
            Button seeaccount = new Button(this);
            seeaccount.setText("See Details");
            seeaccount.setId(i);
            seeaccount.setLayoutParams(new FrameLayout.LayoutParams(200,100));
            seeaccount.setOnClickListener(this);
            horiz.addView(seeaccount); 
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.accountlist, 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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onClick(View view) {
        SharedPreferences sp = getSharedPreferences("details",1);
        int num = sp.getInt("numofaccouns",0);
        for(int x=0;x<=num;x++){
            if(view.getId()==x){
                Intent myaccount = new Intent(AccountlistActivity.this,MyaccountActivity.class);
                myaccount.putExtra("numbtn",x);
                startActivity(myaccount);
            }
        }

    }
}

这是我得到的错误：

Process: com.appschool.www.projectphase1516, PID: 2751
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.appschool.www.projectphase1516/com.appschool.www.projectphase1516.AccountlistActivity}: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
            at android.app.ActivityThread.access$800(ActivityThread.java:135)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5017)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
            at android.view.ViewGroup.addViewInner(ViewGroup.java:3562)
            at android.view.ViewGroup.addView(ViewGroup.java:3415)
            at android.view.ViewGroup.addView(ViewGroup.java:3391)
            at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:309)
            at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:299)
            at android.app.Activity.setContentView(Activity.java:1949)
            at com.appschool.www.projectphase1516.AccountlistActivity.onCreate(AccountlistActivity.java:29)
            at android.app.Activity.performCreate(Activity.java:5231)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
            at android.app.ActivityThread.access$800(ActivityThread.java:135)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5017)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
            at dalvik.system.NativeStart.main(Native Method)

请帮帮我们！

代码应该创建特定数量的按钮和文本视图。

我每次去那个活动时都试图删除并重新创建所有这些，但我不确定为什么我会一直收到错误：[

修改

感谢它现在运行，但还有另一个问题

它不会创建超过1个textview和一个按钮，我不知道为什么

（我对java开发很新，所以我不知道像我上面的评论这样的复杂功能）我只是在做作业：P

Answer 1

删除

setContentView(horiz);

horiz已经是活动内容视图的一部分。

Answer 2

您的方法是错误的，您希望通过创建多个文本视图来显示信息来填充您的布局，您需要的是列表视图和自定义列表适配器，这样您就可以从共享的首选项信息中获取信息将保存在列表中，然后将其传递给适配器，以便适配器可以构建您想要的所有视图，并且比您的方法更好，更轻松地完成它。

Answer 3

第一个答案：horiz已经有一个父母（它已经是你设置的内容视图的一部分）。删除setContentView(horiz)

回答你的第二个问题：

SharedPreferences sp = getSharedPreferences("details",1);
int numofaccounts = sp.getInt("numofaccouns",0);

这意味着您可以使用条目details获得共享偏好（numofaccouns）。然而，那个不存在，因为你永远不会保存它。您只获得一个不存在的条目，如果该条目不存在，则将其默认为0。 forloop初始化为for (int i = 0; i <= numofaccouns; i++)，这意味着你总是点击索引i == 0，因为numofaccouns总是0

final String SHARED_PREFS = "details";
final String NUMBER_OF_ACCOUNTS = "numberOfAccounts";
final int NUMBER_OF_ACCOUNTS_DEFAULT = 10;

int numberOfAccounts = 75;

//to save into sharedpreferences:
getSharedPreferences(SHARED_PREFS, MODE_PRIVATE).edit().put(NUMBER_OF_ACCOUNTS, numberOfAccounts).commit();

//to retrieve that value:
numberOfAccounts = getSharedPreferences(SHARED_PREFS, MODE_PRIVATE).getInt(NUMBER_OF_ACCOUNTS, NUMBER_OF_ACCOUNTS_DEFAULT);

保存所有帐户等等，可以采用与上面给出的示例完全相同的方式完成。

引起：java.lang.IllegalStateException：指定的子节点已经有父节点。您必须首先在孩子的父母上调用removeView（）

3 个答案: