LayoutInflater 不更新视图属性

Question

我只是使用 LayoutInflater 从除 activity_main.xml 之外的 layout.xml 文件中获取视图（按钮）。但是当我更改按钮的 setText("") 属性时，按钮属性不会更新。

我正在检查是否可以更改 testlayout.xml 中按钮元素的文本属性但是当我在 onCreate 中设置 Button 的属性并且当我检查调用中未更改的属性时...

MainActivity.java

 public class MainActivity extends Activity {

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

        LayoutInflater inflater = (LayoutInflater)this.getSystemService
                  (Context.LAYOUT_INFLATER_SERVICE);


        LinearLayout linearLayout = (LinearLayout) inflater.inflate(R.layout.testlayout, null);
        Button btn = (Button)linearLayout.findViewById(R.id.testbtn);
        btn.setText("Hello");
    }


    public void call(View v){

        Button btn  = (Button)findViewById(R.id.testBtn);
        Toast.makeText(this, btn.getText(), Toast.LENGTH_SHORT).show();

    }

Activity_main.xml

    <RelativeLayout 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" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <Button
        android:id="@+id/mainBtn"
        style="?android:attr/buttonStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:layout_marginRight="73dp"
        android:text="Button"
        android:onClick="call"
         />

</RelativeLayout>

testlayout.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/testBtn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />

</LinearLayout>

Answer 1

您需要将此线性布局添加到您的活动中：

 LayoutInflater inflater = (LayoutInflater)this.getSystemService
              (Context.LAYOUT_INFLATER_SERVICE);


    LinearLayout linearLayout = (LinearLayout) inflater.inflate(R.layout.testlayout, null);
    Button btn = (Button)linearLayout.findViewById(R.id.button1);
    btn.setText("Hello");

    RelativeLayout rl=findViewById(R.id.root);
    rl.addView(linearLayout);

Answer 2

您需要使用 ViewGroup.addView(View child) 方法将 testlayout.xml 作为子项添加到活动视图中。目前，您会看到第一个布局中的按钮。你想做什么？

Answer 3

您需要将其他 xml 添加到当前视图中：-

    package com.example.testdynamicviews;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        LinearLayout main = (LinearLayout)findViewById(R.id.mainView); // Your custom view will be added in this layout

        TextView text = myView();
        text.setText("Rahul GuptaRahul GuptaRahul GuptaRahul GuptaRahul GuptaRahul GuptaRahul Gupta");
        main.addView(text); // You forgot to add this line

        Button button = myCustomButton();
        button.setText("Custom Button");
        main.addView(button);
    }

    public TextView myView(){
        View v;
        LayoutInflater li = LayoutInflater.from(getBaseContext());
        v = li.inflate(R.layout.textview, null);
        int width = (int) (getResources().getDimension(R.dimen.testwidth)/ getResources().getDisplayMetrics().density);
        v.setLayoutParams(new LinearLayout.LayoutParams(width,LinearLayout.LayoutParams.WRAP_CONTENT));
        return (TextView) v;
    }

    public Button myCustomButton(){
        View v;
        LayoutInflater li = LayoutInflater.from(getBaseContext());
        v = li.inflate(R.layout.custombutton, null);
        v.setBackgroundColor(Color.RED);
        int width = (int) (getResources().getDimension(R.dimen.testwidth)/ getResources().getDisplayMetrics().density);
        LinearLayout.LayoutParams params= new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT);
        params.setMargins(0, 10, 0, 0);
        v.setLayoutParams(params);
        return (Button) v;
    }
    @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;
    }

}

textview.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="50dp"
    android:layout_height="wrap_content"
    android:text="sgfiughbjkh"
    android:singleLine="true"
    android:textSize="@dimen/testsize"
    android:background="@android:color/holo_blue_bright"
    android:ellipsize="end" >

</TextView>

自定义按钮.xml

    <?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:background="@android:color/holo_blue_bright"
    android:text="sgfiughbjkh"
    android:textSize="@dimen/testsize" />