LayoutInflater的作用类似于 findViewById(),不同点是LayoutInflater是用来找layout文件夹下的xml布局文件，并且实例化！而 findViewById()是找具体某一个xml下的具体 widget控件(如:Button,TextView等)。
自定义Dialog时，通过LayoutInflater实例化layout文件夹下的布局文件的方法有2种。
第1种：
case R.id.button4:
LayoutInflater inflater = (LayoutInflater)getApplicationContext()
.getSystemService(LAYOUT_INFLATER_SERVICE);
View view = inflater.inflate(R.layout.course_custom_dialog, null);
AlertDialog.Builder builder2=new AlertDialog.Builder(MainDialogActivity.this);
builder2.setView(view);
builder2.setTitle("添加课程")
.setPositiveButton("保存", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
})
.setNegativeButton("取消", null)
.create().show();
break;
第2种：
case R.id.button4:
LayoutInflater inflater = (LayoutInflater)LayoutInflater.from(getApplicationContext());
View view = inflater.inflate(R.layout.course_custom_dialog,null);
AlertDialog.Builder builder2=new AlertDialog.Builder(MainDialogActivity.this);
builder2.setView(view);
builder2.setTitle("添加课程")
.setPositiveButton("保存", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
})
.setNegativeButton("取消", null)
.create().show();
break;
