Question

因此，每当我按下LayoutInflate按钮时，我一直在尝试创建一个创建新Button（按顺序使用数字文本）的项目。（我在这篇文章的底部写了一个问题和一个问题）

到目前为止我所做的是：

1.MainActivity java file

- ＆gt;膨胀按钮的java文件在buttonlayout.xml中到mission.xml文件中的Linearlayout

package com.example.a13_1_mission1;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;

public class MainActivity extends AppCompatActivity {

Button btn_inflation;
LinearLayout container;
static int num=1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.mission1);

    btn_inflation= (Button)findViewById(R.id.inflation);
    container = (LinearLayout)findViewById(R.id.container);

    btn_inflation.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            LayoutInflater inflater = getLayoutInflater();
            Button inflatedButton = 
            (Button)inflater.inflate(R.layout.buttonlayout,null);
            inflatedButton.setText("버튼"+(num++));
            container.addView(inflatedButton);
        }
    });



  }

}

2.mission.xml

- ＆gt;提供Linearlayout（包含新按钮）和膨胀Button UI的文件。

<?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">

<Button
    android:id="@+id/inflation"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="5dp"
    android:background="#6999"
    android:gravity="center"
    android:padding="5dp"
    android:text="LayoutInflate"
    android:textAllCaps="false"
    android:textSize="10sp" />




    <LinearLayout
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="20dp"
        android:background="#6999"
        android:orientation="vertical">


    </LinearLayout>

3.buttonlayout.xml

- ＆gt; Button的布局是这里的inflatedenter图像描述（文本大小和东西）。

<?xml version="1.0" encoding="utf-8"?>
<Button xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="10dp">
</Button>

问题＆amp;问题：虽然我在buttonlayout.xml中将width和height设置为wrap_content，但是未正确调整新制造的按钮。这是我的情况照片，以帮助理解：

As you see in the photo, the left one is the objective and the right one is mine.

Answer 1

MainActivity.java

<interactive>:14:1: error:
    * Ambiguous type variable `a0' arising from a use of `print'
      prevents the constraint `(Show a0)' from being solved.
      Probable fix: use a type annotation to specify what `a0' should be.
      These potential instances exist:
        instance [safe] Show Args -- Defined in `Test.QuickCheck.Test'
        instance [safe] Show Result -- Defined in `Test.QuickCheck.Test'
        instance Show All -- Defined in `Data.Monoid'
        ...plus 35 others
        ...plus 22 instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    * In a stmt of an interactive GHCi command: print it

buttonlayout.xml

View view = getLayoutInflater().inflate(R.layout.buttonlayout,null);
((Button)view.findViewById(R.id.button)).setText("\"버튼\"+(num++)");
container.addView(view);

Answer 2

请使用以下代码更新您的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">

    <Button
        android:id="@+id/inflation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:background="#6999"
        android:gravity="center"
        android:padding="5dp"
        android:text="LayoutInflate"
        android:textAllCaps="false"
        android:textSize="10sp" />

    <RelativeLayout
        android:id="@+id/containermain"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="20dp"
        android:background="#6999">

        <LinearLayout
            android:id="@+id/container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="20dp"
            android:orientation="vertical"/>

    </RelativeLayout>
</LinearLayout>

Button wrap_content在LinearLayout中不起作用

2 个答案: