动态将视图添加到布局时的非法状态异常

Question

嗨，我正在编写一个程序来添加动态测试视图。我想在单击按钮时添加文本视图。但是当我添加文本视图时，我收到错误

这是我的日志文件

02-25 22:13:08.835: W/dalvikvm(3609): threadid=1: thread exiting with uncaught exception (group=0x40f102a0)
02-25 22:13:08.843: E/AndroidRuntime(3609): FATAL EXCEPTION: main
02-25 22:13:08.843: E/AndroidRuntime(3609): java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
02-25 22:13:08.843: E/AndroidRuntime(3609):     at android.view.ViewGroup.addViewInner(ViewGroup.java:3387)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at android.view.ViewGroup.addView(ViewGroup.java:3258)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at android.view.ViewGroup.addView(ViewGroup.java:3234)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at com.example.test.MainActivity$1.onClick(MainActivity.java:37)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at android.view.View.performClick(View.java:4222)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at android.view.View$PerformClick.run(View.java:17273)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at android.os.Handler.handleCallback(Handler.java:615)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at android.os.Handler.dispatchMessage(Handler.java:92)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at android.os.Looper.loop(Looper.java:137)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at android.app.ActivityThread.main(ActivityThread.java:4895)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at java.lang.reflect.Method.invokeNative(Native Method)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at java.lang.reflect.Method.invoke(Method.java:511)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:994)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:761)
02-25 22:13:08.843: E/AndroidRuntime(3609):     at dalvik.system.NativeStart.main(Native Method)

我的活动类

import android.os.Bundle;
import android.app.Activity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;
public class MainActivity extends Activity {
    Button btn;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn=(Button)findViewById(R.id.button);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                LinearLayout layout=(LinearLayout)findViewById(R.id.rlayout);
                   LayoutInflater mInflater = (LayoutInflater) getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
                   View  vs= (View) mInflater.inflate(R.layout.test, null);
                TextView textView = (TextView) vs.findViewById(R.id.tview);
                textView.setText("your text");
                LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
                        LinearLayout.LayoutParams.WRAP_CONTENT,
                        LinearLayout.LayoutParams.WRAP_CONTENT);
                layout.addView(textView,p);
            }
        });
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

actvity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" 
    android:id="@+id/rlayout">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    <Button 
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
</LinearLayout>

测试.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:id="@+id/test" >
          <TextView 
              android:id="@+id/tview"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"/>

</LinearLayout>

请帮忙..提前致谢

Answer 1

您正在将文本视图添加到已经具有父级的 LinearLayout。您的错误消息非常清楚。

您需要先从其父布局中删除 TextView，然后才能将其添加到另一个布局。

这样做：

 TextView textView = (TextView) vs.findViewById(R.id.tview);
 vs.removeView(textView); // assuming "vs" is the parent layout of your TextView
 LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
                        LinearLayout.LayoutParams.WRAP_CONTENT,
                        LinearLayout.LayoutParams.WRAP_CONTENT);
 LinearLayout layout = (LinearLayout)findViewById(R.id.rlayout);
 layout.addView(textView,p);

请不要说我只是假设"vs"是TextView的父布局。只需在布局文件中查找，即可获取 TextView 的父布局。然后致电：

parent.removeView(textView);

Answer 2

您尝试添加的文本视图（tview）已经存在于您膨胀的布局中（activity_main）。无法再次添加，因为它已经具有父布局

相反，您应该做一个

TextView

textView = new TextView（v.getContext（））;

动态创建文本视图，然后将其添加到布局中

Answer 3

您的 TextView "textView" 已经存在并附加到视图 "vs"。

对于如此简单的操作，您无需膨胀 xml。您可以执行以下操作：

@Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            LinearLayout layout=(LinearLayout)findViewById(R.id.rlayout);
            TextView textView = new TextView(MainActivity.this);
            textView.setText("your text");
            LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
                    LinearLayout.LayoutParams.WRAP_CONTENT,
                    LinearLayout.LayoutParams.WRAP_CONTENT);
            layout.addView(textView,p);
        }

Answer 4

IllegalStateException正在发生，因为您尝试添加的TextView textView layout是vs的孩子。您应该将vs视图添加到layout中。下面我更新了代码...看看吧。

将以下侦听器代码片段替换为您的代码片段。

    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            LinearLayout layout=(LinearLayout)findViewById(R.id.rlayout);
            LayoutInflater mInflater = (LayoutInflater) getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
            View  vs= (View) mInflater.inflate(R.layout.test, null);
            TextView textView = (TextView) vs.findViewById(R.id.tview);
            textView.setText("your text");
            layout.addView(vs);
        }
    });