大家好我们这一节讲的是LayoutInflater的使用,在实际开发种LayoutInflater这个类还是非常有用的,它的作用类似于 findViewById(),
不同点是LayoutInflater是用来找layout下xml布局文件,并且实例化!而findViewById()是找具体xml下的具体 widget控件(如:Button,TextView等)。
为了让大家容易理解我做了一个简单的Demo,主布局main.xml里有一个TextView和一个Button,当点击Button,出现
Dialog,而这个Dialog的布局方式是我们在layout目录下定义的custom_dialog.xml文件(里面左右分布,左边
ImageView,右边TextView)。
效果图如下:
下面我将详细的说明Demo的实现过程:
1、新建一个 Android工程,我们命名为LayoutInflaterDemo.
2、修改main.xml布局,里面主要在原来基础上增加了一个Button.代码如下:
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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.定义对话框的布局方式,我们在layout目录下,新建一个名为 custom_dialog.xml文件具体代码如下:
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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代码如下:
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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
;
-
-
-
- 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
;
-
-
-
- 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、最后执行之,点击Button,将得到上述效果。
好今天就到此为止,睡觉了,大家有什么不明白的请留言~谢谢!