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尝试通过循环动态添加多个textview时,应用程序崩溃 . 添加单个文本视图时,它可以正常工作

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当我尝试通过以下代码动态添加多个文本视图时,Numbers活动崩溃 . 但是当我不使用循环但只添加文本视图时,它工作正常 .

Numbers Activity.java

public class NumbersActivity extends AppCompatActivity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_numbers);

        ArrayList<String> words = new ArrayList<String>();
        words.add("one");
        words.add("two");
        words.add("three");
        words.add("four");
        words.add("five");
        words.add("six");
        words.add("seven");
        words.add("eight");
        words.add("nine");
        words.add("ten");

        LinearLayout rootView = (LinearLayout) findViewById(R.id.rootView);
        rootView.removeAllViews();
        TextView  wordView = new TextView((this));
        int index;
        for(index=0; index<words.size(); index++ ){
            wordView.setText(words.get(index));
            rootView.addView(wordView);

        }
    }
}

activity_numbers.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/rootView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginLeft="16dp"
    android:orientation="vertical"
    tools:context=".NumbersActivity"
</LinearLayout>

我得到的错误是在应用程序崩溃之后

E / AndroidRuntime:FATAL EXCEPTION:main进程:com.example.yusuf.miwok,PID:12226 java.lang.RuntimeException:无法启动活动ComponentInfo {com.example.yusuf.miwok / com.example.yusuf.miwok . NumbersActivity}:java.lang.IllegalStateException:指定的子级已有父级 . 您必须首先在孩子的父母上调用removeView() . 在Android.app.A活动中的android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3194)android.app.A活动时,我发现它位于android.app.A活动时,活动强化(ActivityThread.java:3302) . ActivityThread $ H.handleMessage(ActivityThread.java:1891)位于android.app.AooT.Thread.main的android.os.Handler.dispatchMessage(Handler.java:108)android.os.Looper.loop(Looper.java:166) (ActivityThread.java:7425)位于com.android.internal.os的com.android.internal.os.Zygote $ MethodAndArgsCaller.run(Zygote.java:245)的java.lang.reflect.Method.invoke(Native Method) .ZygoteInit.main(ZygoteInit.java:921)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() . 在Android.view上的android.view.ViewGroup.addView(ViewGroup.java:4747)上的android.view.ViewGroup.addViewInner中的android.view.ViewGroup.addViewInner(ViewGroup.java:4976) . 位于android.app.Instrumentation的android.app.Activity.performCreate(Activity.java:7372)的com.example.yusuf.miwok.NumbersActivity.onCreate(NumbersActivity.java:40)中的ViewGroup.addView(ViewGroup.java:4720) .callActivityOnCreate(Instrumentation.java:1218)位于android.app.A活动中的android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3147)android.app.A活动 . 活动(活动传递:3:3),android.app.ActivityThread.-wrap12(未知)来源:0)在android.app.Loper.loop(Looper.java:166)的android.app.Handler.dispatchMessage(Handler.java:108)上的android.app.ActivityThread $ H.handleMessage(ActivityThread.java:1891) )在android.app.ActivityThread.main(ActivityThread.java:7425)at java.lang.reflect.Method.invoke(Native Method)at com.android.internal.os.Zygote $ MethodAndArgsCaller.run(Zygote.jav) a:245)at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:921)I / Process:发送信号 . PID:12226 SIG:9应用程序终止 .

1 回答

  • 3

    正确的代码如下

    public class NumbersActivity extends AppCompatActivity{
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_numbers);
    
            ArrayList<String> words = new ArrayList<String>();
            words.add("one");
            words.add("two");
            words.add("three");
            words.add("four");
            words.add("five");
            words.add("six");
            words.add("seven");
            words.add("eight");
            words.add("nine");
            words.add("ten");
    
            LinearLayout rootView = (LinearLayout) findViewById(R.id.rootView);
            rootView.removeAllViews();
    
            int index;
            for(index=0; index<words.size(); index++ ){
                TextView  wordView = new TextView((this));
                wordView.setText(words.get(index));
                rootView.addView(wordView);
    
            }
        }
    }
    

    请注意,我只是将此行移至for循环内部

    TextView  wordView = new TextView((this));
    

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