DialogFragment

            
转载请标明出处：http://blog.csdn.net/lmj623565791/article/details/37815413
1、 概述
DialogFragment在android 3.0时被引入。是一种特殊的Fragment，用于在Activity的内容之上展示一个模态的对话框。典型的用于：展示警告框，输入框，确认框等等。
在DialogFragment产生之前，我们创建对话框：一般采用AlertDialog和Dialog。注：官方不推荐直接使用Dialog创建对话框。
2、 好处与用法
使用DialogFragment来管理对话框，当旋转屏幕和按下后退键时可以更好的管理其声明周期，它和Fragment有着基本一致的声明周期。且DialogFragment也允许开发者把Dialog作为内嵌的组件进行重用，类似Fragment（可以在大屏幕和小屏幕显示出不同的效果）。上面会通过例子展示这些好处~
使用DialogFragment至少需要实现onCreateView或者onCreateDIalog方法。onCreateView即使用定义的xml布局文件展示Dialog。onCreateDialog即利用AlertDialog或者Dialog创建出Dialog。
3、 重写onCreateView创建Dialog
a)布局文件，我们创建一个设置名称的布局文件：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >

    <TextView
        android:id="@+id/id_label_your_name"
        android:layout_width="wrap_content"
        android:layout_height="32dp"
        android:gravity="center_vertical"
        android:text="Your name:" />

    <EditText
        android:id="@+id/id_txt_your_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@id/id_label_your_name"
        android:imeOptions="actionDone"
        android:inputType="text" />

    <Button
        android:id="@+id/id_sure_edit_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_below="@id/id_txt_your_name"
        android:text="ok" />

</RelativeLayout>
<?xml version="1.0" encoding="utf-8"?>
 
  
 android:layout_width=”wrap_content” 
 android:layout_height=”wrap_content” >
 
  
<TextView
    android:id="@+id/id_label_your_name"
    android:layout_width="wrap_content"
    android:layout_height="32dp"
    android:gravity="center_vertical"
    android:text="Your name:" />

<EditText
    android:id="@+id/id_txt_your_name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_toRightOf="@id/id_label_your_name"
    android:imeOptions="actionDone"
    android:inputType="text" />

<Button
    android:id="@+id/id_sure_edit_name"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_below="@id/id_txt_your_name"
    android:text="ok" />
 
  

b)继承DialogFragment，重写onCreateView方法
 
  
 
  
 
  
package com.example.zhy_dialogfragment;

import android.app.DialogFragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class EditNameDialogFragment extends DialogFragment
{


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState)
    {
        View view = inflater.inflate(R.layout.fragment_edit_name, container);
        return view;
    }

}
 
  
package com.example.zhy_dialogfragment;

import android.app.DialogFragment; 

import android.os.Bundle; 

import android.view.LayoutInflater; 

import android.view.View; 

import android.view.ViewGroup;

public class EditNameDialogFragment extends DialogFragment 

{

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState)
{
    View view = inflater.inflate(R.layout.fragment_edit_name, container);
    return view;
}


} 

 
  
c)测试运行： 
  
 
  
Main方法中调用：
 
  
 
  
public void showEditDialog(View view)
    {
        EditNameDialogFragment editNameDialog = new EditNameDialogFragment();
        editNameDialog.show(getFragmentManager(), ”EditNameDialog”);
    }
 
  
public void showEditDialog(View view) 

    { 

        EditNameDialogFragment editNameDialog = new EditNameDialogFragment(); 

        editNameDialog.show(getFragmentManager(), "EditNameDialog"); 

    } 

效果图： 
  
 
  
 
  
 
    
  
 
  

    可以看到，对话框成功创建并显示出来，不过默认对话框有个讨厌的标题，我们怎么去掉呢：可以在onCreateView中调用getDialog().requestWindowFeature(Window.FEATURE_NO_TITLE);即可去掉。即： 
  
 
  
 
   
public class EditNameDialogFragment extends DialogFragment
{

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState)
    {
        getDialog().requestWindowFeature(Window.FEATURE_NO_TITLE);
        View view = inflater.inflate(R.layout.fragment_edit_name, container);
        return view;
    }

}
 
   
public class EditNameDialogFragment extends DialogFragment 

{

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState)
{
    getDialog().requestWindowFeature(Window.FEATURE_NO_TITLE);
    View view = inflater.inflate(R.layout.fragment_edit_name, container);
    return view;
}


} 

 
   
效果图： 
  
 
  
 
    
   
 
  
 
  

    很完美的去掉了讨厌的标题。 
  
 
  
 
   
 
  
 
  
4、 重写onCreateDialog创建Dialog
在onCreateDialog中一般可以使用AlertDialog或者Dialog创建对话框，不过既然google不推荐直接使用Dialog，我们就使用AlertDialog来创建一个登录的对话框。 
  
 
  
a)布局文件
 
  
 
  
xml version=“1.0” encoding=“utf-8”?>
<LinearLayout xmlns:android=”http://schemas.android.com/apk/res/android”
    android:layout_width=“wrap_content”
    android:layout_height=“wrap_content”
    android:orientation=“vertical” >

    <ImageView
        android:layout_width=“match_parent”
        android:layout_height=“64dp”
        android:background=“#FFFFBB33”
        android:contentDescription=“@string/app_name”
        android:scaleType=“center”
        android:src=“@drawable/title” />

    <EditText
        android:id=“@+id/id_txt_username”
        android:layout_width=“match_parent”
        android:layout_height=“wrap_content”
        android:layout_marginBottom=“4dp”
        android:layout_marginLeft=“4dp”
        android:layout_marginRight=“4dp”
        android:layout_marginTop=“16dp”
        android:hint=“input username”
        android:inputType=“textEmailAddress” />

    <EditText
        android:id=“@+id/id_txt_password”
        android:layout_width=“match_parent”
        android:layout_height=“wrap_content”
        android:layout_marginBottom=“16dp”
        android:layout_marginLeft=“4dp”
        android:layout_marginRight=“4dp”
        android:layout_marginTop=“4dp”
        android:fontFamily=“sans-serif”
        android:hint=“input password”
        android:inputType=“textPassword” />

LinearLayout>
 
  
 


    android:layout_width="wrap_content" 

    android:layout_height="wrap_content" 

    android:orientation="vertical" >

<ImageView
    android:layout_width="match_parent"
    android:layout_height="64dp"
    android:background="#FFFFBB33"
    android:contentDescription="@string/app_name"
    android:scaleType="center"
    android:src="@drawable/title" />

<EditText
    android:id="@+id/id_txt_username"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="4dp"
    android:layout_marginLeft="4dp"
    android:layout_marginRight="4dp"
    android:layout_marginTop="16dp"
    android:hint="input username"
    android:inputType="textEmailAddress" />

<EditText
    android:id="@+id/id_txt_password"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="16dp"
    android:layout_marginLeft="4dp"
    android:layout_marginRight="4dp"
    android:layout_marginTop="4dp"
    android:fontFamily="sans-serif"
    android:hint="input password"
    android:inputType="textPassword" />


 
  
b)继承DialogFragment重写onCreateDialog方法 
  
 
  
 
  
package com.example.zhy_dialogfragment;

import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;

public class LoginDialogFragment extends DialogFragment
{

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState)
    {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        // Get the layout inflater
        LayoutInflater inflater = getActivity().getLayoutInflater();
        View view = inflater.inflate(R.layout.fragment_login_dialog, null);
        // Inflate and set the layout for the dialog
        // Pass null as the parent view because its going in the dialog layout
        builder.setView(view)
                // Add action buttons
                .setPositiveButton(”Sign in”,
                        new DialogInterface.OnClickListener()
                        {
                            @Override
                            public void onClick(DialogInterface dialog, int id)
                            {
                            }
                        }).setNegativeButton(”Cancel”, null);
        return builder.create();
    }
}
 
  
package com.example.zhy_dialogfragment;

import android.app.AlertDialog; 

import android.app.Dialog; 

import android.app.DialogFragment; 

import android.content.DialogInterface; 

import android.os.Bundle; 

import android.view.LayoutInflater; 

import android.view.View; 

import android.view.ViewGroup; 

import android.widget.EditText;

public class LoginDialogFragment extends DialogFragment 

{

@Override
public Dialog onCreateDialog(Bundle savedInstanceState)
{
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    // Get the layout inflater
    LayoutInflater inflater = getActivity().getLayoutInflater();
    View view = inflater.inflate(R.layout.fragment_login_dialog, null);
    // Inflate and set the layout for the dialog
    // Pass null as the parent view because its going in the dialog layout
    builder.setView(view)
            // Add action buttons
            .setPositiveButton("Sign in",
                    new DialogInterface.OnClickListener()
                    {
                        @Override
                        public void onClick(DialogInterface dialog, int id)
                        {
                        }
                    }).setNegativeButton("Cancel", null);
    return builder.create();
}


} 

 
  
c)调用 
  
 
  
 
  
public void showLoginDialog(View view)
    {
        LoginDialogFragment dialog = new LoginDialogFragment();
        dialog.show(getFragmentManager(), ”loginDialog”);
    }
 
  
public void showLoginDialog(View view) 

    { 

        LoginDialogFragment dialog = new LoginDialogFragment(); 

        dialog.show(getFragmentManager(), "loginDialog"); 

    } 

 
  
效果图： 
  
 
  
 
  

 
  
可以看到通过重写onCreateDialog同样可以实现创建对话框，效果还是很nice的。
 
  
5、传递数据给Activity
 
  
从dialog传递数据给Activity，可以使用“fragment interface pattern”的方式，下面通过一个改造上面的登录框来展示这种模式。
 
  
改动比较小，直接贴代码了：
 
  
 
  
package com.example.zhy_dialogfragment;

import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;

public class LoginDialogFragment extends DialogFragment
{
    private EditText mUsername;
    private EditText mPassword;

    public interface LoginInputListener
    {
        void onLoginInputComplete(String username, String password);
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState)
    {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        // Get the layout inflater
        LayoutInflater inflater = getActivity().getLayoutInflater();
        View view = inflater.inflate(R.layout.fragment_login_dialog, null);
        mUsername = (EditText) view.findViewById(R.id.id_txt_username);
        mPassword = (EditText) view.findViewById(R.id.id_txt_password);
        // Inflate and set the layout for the dialog
        // Pass null as the parent view because its going in the dialog layout
        builder.setView(view)
                // Add action buttons
                .setPositiveButton(”Sign in”,
                        new DialogInterface.OnClickListener()
                        {
                            @Override
                            public void onClick(DialogInterface dialog, int id)
                            {
                                LoginInputListener listener = (LoginInputListener) getActivity();
                                listener.onLoginInputComplete(mUsername
                                        .getText().toString(), mPassword
                                        .getText().toString());
                            }
                        }).setNegativeButton(”Cancel”, null);
        return builder.create();
    }
}
 
  
package com.example.zhy_dialogfragment;

import android.app.AlertDialog; 

import android.app.Dialog; 

import android.app.DialogFragment; 

import android.content.DialogInterface; 

import android.os.Bundle; 

import android.view.LayoutInflater; 

import android.view.View; 

import android.view.ViewGroup; 

import android.widget.EditText;

public class LoginDialogFragment extends DialogFragment 

{ 

    private EditText mUsername; 

    private EditText mPassword;

public interface LoginInputListener
{
    void onLoginInputComplete(String username, String password);
}

@Override
public Dialog onCreateDialog(Bundle savedInstanceState)
{
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    // Get the layout inflater
    LayoutInflater inflater = getActivity().getLayoutInflater();
    View view = inflater.inflate(R.layout.fragment_login_dialog, null);
    mUsername = (EditText) view.findViewById(R.id.id_txt_username);
    mPassword = (EditText) view.findViewById(R.id.id_txt_password);
    // Inflate and set the layout for the dialog
    // Pass null as the parent view because its going in the dialog layout
    builder.setView(view)
            // Add action buttons
            .setPositiveButton("Sign in",
                    new DialogInterface.OnClickListener()
                    {
                        @Override
                        public void onClick(DialogInterface dialog, int id)
                        {
                            LoginInputListener listener = (LoginInputListener) getActivity();
                            listener.onLoginInputComplete(mUsername
                                    .getText().toString(), mPassword
                                    .getText().toString());
                        }
                    }).setNegativeButton("Cancel", null);
    return builder.create();
}


} 

 
  
拿到username和password的引用，在点击登录的时候，把activity强转为我们自定义的接口：LoginInputListener，然后将用户输入的数据返回。 
  
 
  
MainActivity中需要实现我们的接口LoginInputListener，实现我们的方法，就可以实现当用户点击登陆时，获得我们的帐号密码了：
 
  
 
  
c)  MainActivity
package com.example.zhy_dialogfragment;

import com.example.zhy_dialogfragment.LoginDialogFragment.LoginInputListener;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity implements LoginInputListener
{

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



    public void showLoginDialog(View view)
    {
        LoginDialogFragment dialog = new LoginDialogFragment();
        dialog.show(getFragmentManager(), ”loginDialog”);

    }

    @Override
    public void onLoginInputComplete(String username, String password)
    {
        Toast.makeText(this, “帐号：” + username + “,  密码 :” + password,
                Toast.LENGTH_SHORT).show();
    }

}
 
  
c)  MainActivity 

package com.example.zhy_dialogfragment;

import com.example.zhy_dialogfragment.LoginDialogFragment.LoginInputListener;

import android.app.Activity; 

import android.app.AlertDialog; 

import android.content.DialogInterface; 

import android.os.Bundle; 

import android.view.LayoutInflater; 

import android.view.View; 

import android.widget.Toast;

public class MainActivity extends Activity implements LoginInputListener 

{

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



public void showLoginDialog(View view)
{
    LoginDialogFragment dialog = new LoginDialogFragment();
    dialog.show(getFragmentManager(), "loginDialog");

}

@Override
public void onLoginInputComplete(String username, String password)
{
    Toast.makeText(this, "帐号：" + username + ",  密码 :" + password,
            Toast.LENGTH_SHORT).show();
}


} 

 
  
效果： 
  
 
  

 
  
6、DialogFragment做屏幕适配
 
  
我们希望，一个对话框在大屏幕上以对话框的形式展示，而小屏幕上则直接嵌入当前的Actvity中。这种效果的对话框，只能通过重写onCreateView实现。下面我们利用上面的EditNameDialogFragment来显示。
 
  
EditNameDialogFragment我们已经编写好了，直接在MainActivity中写调用
 
  
 
  
public void showDialogInDifferentScreen(View view)
    {
        FragmentManager fragmentManager = getFragmentManager();
        EditNameDialogFragment newFragment = new EditNameDialogFragment();

        boolean mIsLargeLayout = getResources().getBoolean(R.bool.large_layout) ;
        Log.e(”TAG”, mIsLargeLayout+“”);
        if (mIsLargeLayout )
        {
            // The device is using a large layout, so show the fragment as a
            // dialog
            newFragment.show(fragmentManager, ”dialog”);
        } else
        {
            // The device is smaller, so show the fragment fullscreen
            FragmentTransaction transaction = fragmentManager
                    .beginTransaction();
            // For a little polish, specify a transition animation
            transaction
                    .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
            // To make it fullscreen, use the ‘content’ root view as the
            // container
            // for the fragment, which is always the root view for the activity
            transaction.replace(R.id.id_ly, newFragment)
                    .commit();
        }
    }
 
  
public void showDialogInDifferentScreen(View view) 

    { 

        FragmentManager fragmentManager = getFragmentManager(); 

        EditNameDialogFragment newFragment = new EditNameDialogFragment();

    boolean mIsLargeLayout = getResources().getBoolean(R.bool.large_layout) ;
    Log.e("TAG", mIsLargeLayout+"");
    if (mIsLargeLayout )
    {
        // The device is using a large layout, so show the fragment as a
        // dialog
        newFragment.show(fragmentManager, "dialog");
    } else
    {
        // The device is smaller, so show the fragment fullscreen
        FragmentTransaction transaction = fragmentManager
                .beginTransaction();
        // For a little polish, specify a transition animation
        transaction
                .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
        // To make it fullscreen, use the 'content' root view as the
        // container
        // for the fragment, which is always the root view for the activity
        transaction.replace(R.id.id_ly, newFragment)
                .commit();
    }
}

可以看到，我们通过读取R.bool.large_layout，然后根据得到的布尔值，如果是大屏幕则直接以对话框显示，如果是小屏幕则嵌入我们的Activity布局中
这个R.bool.large_layout是我们定义的资源文件：
在默认的values下新建一个bools.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>

    <bool name="large_layout">false</bool>

</resources>
<?xml version="1.0" encoding="utf-8"?>




<bool name="large_layout">false</bool>


 
  
然后在res下新建一个values-large，在values-large下再新建一个bools.xml 
  
 
  
 
  
xml version=“1.0” encoding=“utf-8”?>
<resources>

    <bool name=“large_layout”>truebool>

resources>
 
  
 



<bool name="large_layout">true</bool>


 
  
最后测试： 
  
 
  
          
 
  
左边为模拟器，右边为我的手机~
 
  
7、屏幕旋转
 
  
当用户输入帐号密码时，忽然旋转了一下屏幕，帐号密码不见了~~~是不是会抓狂
 
  
传统的new AlertDialog在屏幕旋转时，第一不会保存用户输入的值，第二还会报异常，因为Activity销毁前不允许对话框未关闭。而通过DialogFragment实现的对话框则可以完全不必考虑旋转的问题。
 
  
我们直接把上面登录使用AlertDialog创建的登录框，拷贝到MainActivity中直接调用：
 
  
 
  
public void showLoginDialogWithoutFragment(View view)
    {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        // Get the layout inflater
        LayoutInflater inflater = this.getLayoutInflater();

        // Inflate and set the layout for the dialog
        // Pass null as the parent view because its going in the dialog layout
        builder.setView(inflater.inflate(R.layout.fragment_login_dialog, null))
                // Add action buttons
                .setPositiveButton(”Sign in”,
                        new DialogInterface.OnClickListener()
                        {
                            @Override
                            public void onClick(DialogInterface dialog, int id)
                            {
                                // sign in the user …
                            }
                        }).setNegativeButton(”Cancel”, null).show();
    }
 
  
public void showLoginDialogWithoutFragment(View view) 

    { 

        AlertDialog.Builder builder = new AlertDialog.Builder(this); 

        // Get the layout inflater 

        LayoutInflater inflater = this.getLayoutInflater();

    // Inflate and set the layout for the dialog
    // Pass null as the parent view because its going in the dialog layout
    builder.setView(inflater.inflate(R.layout.fragment_login_dialog, null))
            // Add action buttons
            .setPositiveButton("Sign in",
                    new DialogInterface.OnClickListener()
                    {
                        @Override
                        public void onClick(DialogInterface dialog, int id)
                        {
                            // sign in the user ...
                        }
                    }).setNegativeButton("Cancel", null).show();
}


 
  
下面我分别点击两种方式创建的登录框，看效果图： 
  
 
  

 
  
可以看到，传统的Dialog旋转屏幕时就消失了，且后台log会报异常~使用DialogFragment则不受影响。
 
  

 
  

 
  
好了，关于DialogFragment的介绍结束~~
 
  

 
  
有任何疑问请留言
 
  

 
  
源码点击下载
 
  

 
  
参考文档：
 
  
http://developer.android.com/guide/topics/ui/dialogs.html#DialogFragment
 
  
https://github.com/thecodepath/android_guides/wiki/Using-DialogFragment