LayoutInflater的使用

LayoutInflater的作用和findViewById()差不多,不同之处在于LayoutInflater是找layout文件夹下的某个xml布局文件！而 findViewById()是找某一个xml下的具体 widget控件。

LayoutInflater可以将一个xml布局文件转化为View 类型，其代码如下：

 1 package hzx.one; 2  3 import android.app.Activity; 4 import android.app.AlertDialog; 5 import android.app.AlertDialog.Builder; 6 import android.content.DialogInterface; 7 import android.os.Bundle; 8 import android.view.LayoutInflater; 9 import android.view.View;10 import android.view.ViewGroup;11 import android.widget.Button;12 import android.widget.Toast;13 14 public class HzxDialogActivity extends Activity {15     private Button button1;16     private Button button2;17     private Button button3;18     @Override19     public void onCreate(Bundle savedInstanceState) {20         super.onCreate(savedInstanceState);21         setContentView(R.layout.main);22         button1=(Button) findViewById(R.id.button1);23         button1.setText("默认dialog");24         button1.setOnClickListener(new View.OnClickListener() {25             @Override26             public void onClick(View v) {showDialog1();}});27         button2=(Button) findViewById(R.id.button2);28         button2.setText("自定义dialog");29         button2.setOnClickListener(new View.OnClickListener() {30             @Override31             public void onClick(View v) {showDialog2();}});32         button3=(Button) findViewById(R.id.button3);33         button3.setText("自定义toast");34         button3.setOnClickListener(new View.OnClickListener() {35             @Override36             public void onClick(View v) {37                 Toast toast=new Toast(HzxDialogActivity.this);38                 //三种方法定义LayoutInflater39                 //LayoutInflater li=getLayoutInflater();40                 //LayoutInflater li = LayoutInflater.from(HzxDialogActivity.this); 41                 LayoutInflater li = (LayoutInflater)getSystemService(LAYOUT_INFLATER_SERVICE);42                 43                 View view=li.inflate(R.layout.dialog, (ViewGroup)findViewById(R.id.dialog));44                 toast.setView(view);45                 toast.setDuration(Toast.LENGTH_SHORT);46                 toast.setGravity(0, -20, 20);47                 toast.show();48             }});49     }50     private void showDialog1() {51         AlertDialog.Builder builder=new Builder(this);52         builder.setMessage("are you sure to exit ?");53         builder.setTitle("exit or not ");54         builder.setPositiveButton("yes", new DialogInterface.OnClickListener() {55             @Override56             public void onClick(DialogInterface dialog, int which) {dialog.dismiss();HzxDialogActivity.this.finish();}});57         builder.setNegativeButton("no", new DialogInterface.OnClickListener() {58             @Override59             public void onClick(DialogInterface dialog, int which) {dialog.dismiss();}});60         builder.create().show();61     }62     private void showDialog2(){63         AlertDialog.Builder builder=new Builder(this);64         LayoutInflater li=getLayoutInflater();65         View v=li.inflate(R.layout.dialog, (ViewGroup)findViewById(R.id.dialog));66         builder.setView(v);67         builder.setPositiveButton("yes", new DialogInterface.OnClickListener() {68             @Override69             public void onClick(DialogInterface dialog, int which) {dialog.dismiss();HzxDialogActivity.this.finish();}});70         builder.setNegativeButton("no", new DialogInterface.OnClickListener() {71             @Override72             public void onClick(DialogInterface dialog, int which) {dialog.dismiss();}});73         builder.create().show();74     }75 }

main.xml布局文件

<?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3     android:layout_width="fill_parent" 4     android:layout_height="fill_parent" android:orientation="vertical"> 5 <TextView   6     android:layout_width="fill_parent"  7     android:layout_height="wrap_content"  8     android:text="@string/hello" 9     />10 <Button android:text="Button" android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>11 <Button android:text="Button" android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>12 <Button android:text="Button" android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>13 </LinearLayout>

dialog.xml布局文件

<?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3     android:layout_width="fill_parent" 4     android:layout_height="fill_parent" 5     android:orientation="horizontal" 6     android:id="@+id/dialog"> 7      8     <ImageView android:id="@+id/imageView1" android:layout_height="wrap_content" android:src="@drawable/icon" android:layout_width="wrap_content"></ImageView> 9     <TextView android:layout_height="wrap_content" android:text="@string/hello" android:layout_width="wrap_content" android:id="@+id/textView1"></TextView>10 </LinearLayout>

演示结果如下：

默认dialog:

自定义dialog:

自定义toast：