Android高手進階教程(五)之----Android 中LayoutInflater的使用! （轉）

原創作品，允許轉載，轉載時請務必以超鏈接形式標明文章 原始出處 、作者信息和本聲明。否則將追究法律責任。http://weizhulin.blog.51cto.com/1556324/311450

大家好我們這一節講的是LayoutInflater的使用,在實際開發種LayoutInflater這個類還是非常有用的,它的作用類似於 findViewById(),

不同點是LayoutInflater是用來找layout下xml佈局文件，並且實例化！而findViewById()是找具體xml下的具體 widget控件(如:Button,TextView等)。

爲了讓大家容易理解我做了一個簡單的Demo,主佈局main.xml裏有一個TextView和一個Button，當點擊Button，出現 Dialog,而這個Dialog的佈局方式是我們在layout目錄下定義的custom_dialog.xml文件(裏面左右分佈，左邊 ImageView,右邊TextView)。

效果圖如下:

 

下面我將詳細的說明Demo的實現過程:

1、新建一個 Android工程，我們命名爲LayoutInflaterDemo.

2、修改main.xml佈局，裏面主要在原來基礎上增加了一個Button.代碼如下:

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<?
xml
 
version
=
"1.0"
encoding
=
"utf-8"
?>
<
LinearLayout
xmlns:android
=
"http://schemas.android.com/apk/res/android"
    
android:orientation
=
"vertical"
    
android:layout_width
=
"fill_parent"
    
android:layout_height
=
"fill_parent"
    
>
<
TextView
    
android:layout_width
=
"fill_parent"
    
android:layout_height
=
"wrap_content"
    
android:text
=
"@string/hello"
    
/>
<
Button
    
android:id
=
"@+id/button"
    
android:layout_width
=
"wrap_content"
    
android:layout_height
=
"wrap_content"
    
android:text
=
"ShowCustomDialog"
    
/>
</
LinearLayout
>
<?
xml
 
version
=
"1.0"
encoding
=
"utf-8"
?>
<
LinearLayout
xmlns:android
=
"http://schemas.android.com/apk/res/android"
    
android:orientation
=
"vertical"
    
android:layout_width
=
"fill_parent"
    
android:layout_height
=
"fill_parent"
    
>
<
TextView
    
android:layout_width
=
"fill_parent"
    
android:layout_height
=
"wrap_content"
    
android:text
=
"@string/hello"
    
/>
<
Button
 
android:id
=
"@+id/button"
 
android:layout_width
=
"wrap_content"
 
android:layout_height
=
"wrap_content"
 
android:text
=
"ShowCustomDialog"
 
/>
</
LinearLayout
>

 

3.定義對話框的佈局方式，我們在layout目錄下，新建一個名爲 custom_dialog.xml文件具體代碼如下:

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<?
xml
 
version
=
"1.0"
encoding
=
"utf-8"
?>
<
LinearLayout
xmlns:android
=
"http://schemas.android.com/apk/res/android"
              
android:orientation
=
"horizontal"
              
android:layout_width
=
"fill_parent"
              
android:layout_height
=
"fill_parent"
              
android:padding
=
"10dp"
              
>
    
<
ImageView
 
android:id
=
"@+id/image"
               
android:layout_width
=
"wrap_content"
               
android:layout_height
=
"fill_parent"
               
android:layout_marginRight
=
"10dp"
               
/>
    
<
TextView
 
android:id
=
"@+id/text"
              
android:layout_width
=
"wrap_content"
              
android:layout_height
=
"fill_parent"
              
android:textColor
=
"#FFF"
              
/>
</
LinearLayout
>
<?
xml
 
version
=
"1.0"
encoding
=
"utf-8"
?>
<
LinearLayout
xmlns:android
=
"http://schemas.android.com/apk/res/android"
              
android:orientation
=
"horizontal"
              
android:layout_width
=
"fill_parent"
              
android:layout_height
=
"fill_parent"
              
android:padding
=
"10dp"
              
>
    
<
ImageView
 
android:id
=
"@+id/image"
               
android:layout_width
=
"wrap_content"
               
android:layout_height
=
"fill_parent"
               
android:layout_marginRight
=
"10dp"
               
/>
    
<
TextView
 
android:id
=
"@+id/text"
              
android:layout_width
=
"wrap_content"
              
android:layout_height
=
"fill_parent"
              
android:textColor
=
"#FFF"
              
/>
</
LinearLayout
>

 

4.修改主程序LayouInflaterDemo.java代碼如下:

 

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package
 com.android.tutor;
import
 android.app.Activity;
import
 android.app.AlertDialog;
import
 android.content.Context;
import
 android.os.Bundle;
import
 android.view.LayoutInflater;
import
 android.view.View;
import
 android.view.View.OnClickListener;
import
 android.widget.Button;
import
 android.widget.ImageView;
import
 android.widget.TextView;
public
 
class
 LayoutInflaterDemo 
extends
 Activity 
implements
OnClickListener {

    
private
 Button button;
    
public
 
void
 onCreate(Bundle savedInstanceState) {
        
super
.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        button = (Button)findViewById(R.id.button);
        button.setOnClickListener(
this
);
    }
    
@Override
    
public
 
void
 onClick(View v) {

        showCustomDialog();
    }

    
public
 
void
 showCustomDialog()
    {
        AlertDialog.Builder builder;
        AlertDialog alertDialog;
        Context mContext = LayoutInflaterDemo.
this
;

        
//下面倆種方法都可以
        
////LayoutInflater inflater = getLayoutInflater();
        LayoutInflater inflater = (LayoutInflater)
mContext.getSystemService(LAYOUT_INFLATER_SERVICE);
        View layout = inflater.inflate(R.layout.custom_dialog,
null
);
        TextView text = (TextView) layout.findViewById(R.id.text);
        text.setText(
"Hello, Welcome to Mr Wei's blog!"
);
        ImageView image = (ImageView) layout.findViewById(R.id.image);
        image.setImageResource(R.drawable.icon);
        builder = 
new
 AlertDialog.Builder(mContext);
        builder.setView(layout);
        alertDialog = builder.create();
        alertDialog.show();
    }
}
package
 com.android.tutor;
import
 android.app.Activity;
import
 android.app.AlertDialog;
import
 android.content.Context;
import
 android.os.Bundle;
import
 android.view.LayoutInflater;
import
 android.view.View;
import
 android.view.View.OnClickListener;
import
 android.widget.Button;
import
 android.widget.ImageView;
import
 android.widget.TextView;
public
 
class
 LayoutInflaterDemo 
extends
 Activity 
implements
OnClickListener {

 
private
 Button button;
    
public
 
void
 onCreate(Bundle savedInstanceState) {
        
super
.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        button = (Button)findViewById(R.id.button);
        button.setOnClickListener(
this
);
    }
 
@Override
 
public
 
void
 onClick(View v) {

  showCustomDialog();
 }

 
public
 
void
 showCustomDialog()
 {
  AlertDialog.Builder builder;
  AlertDialog alertDialog;
  Context mContext = LayoutInflaterDemo.
this
;

  
//下面倆種方法都可以
  
////LayoutInflater inflater = getLayoutInflater();
  LayoutInflater inflater = (LayoutInflater)
mContext.getSystemService(LAYOUT_INFLATER_SERVICE);
  View layout = inflater.inflate(R.layout.custom_dialog,
null
);
  TextView text = (TextView) layout.findViewById(R.id.text);
  text.setText(
"Hello, Welcome to Mr Wei's blog!"
);
  ImageView image = (ImageView) layout.findViewById(R.id.image);
  image.setImageResource(R.drawable.icon);
  builder = 
new
 AlertDialog.Builder(mContext);
  builder.setView(layout);
  alertDialog = builder.create();
  alertDialog.show();
 }
}

5、最後執行之，點擊Button，將得到上述效果。

 好今天就到此爲止，睡覺了，大家有什麼不明白的請留言~謝謝!