`
wayfarer
  • 浏览: 294352 次
  • 性别: Icon_minigender_1
  • 来自: 上海
社区版块
存档分类
最新评论

Dialog

阅读更多

Dialog是所有对话框的基类,但Dialog并非继承自View,而是直接从Object构造出来的。Dialog调用是异步调用,所以showDialog()时不会阻碍UI线程。

 

1. Activity托管对话框:
      Android提供了创建对话框的快捷方式,在Activity中可以通过如showDialog(int dialogId),dismissDialog(int dialogId),onCreateDialog(),onPrepareDialog(),removeDialog()等方法来创建和管理对话框。

      onCreateDialog(int dialogId)和onPrepareDialog(int dialogId, Dialog dialog)是Dialog的2个回调函数,showDialog()触发这两个回调函数的调用。同所有的onCreate()一样,其只在Dialog第一次生成的时候才会被调用,而onPrepareDialog()在每次执行showDialog()都会被调用(不管Dialog生成了没有)。如果你想要更新对话框的内容,你只要在onPrepareDialog()中作相应的工作就可以了,该方法会在对话框显示之前进行调用。

      dismissDialog()方法是用来关闭对话框的;removeDialog()方法用来将对话框从Activity的托管中移除(如果对已经移除的对话框重新进行调用showDialog ,则该对话框将进行重新创建)。

 

2. 常用Dialog

(1)AlertDialog

AlertDialog类是Dialog类的子类,它默认提供了3个按钮和一个文本消息,这些按钮可以按需要来使他们显示或隐藏。AlertDialog类中有一个内部静态类,名为“Builder”,Builder类提供了为对话框添加多选或单选列表,以及为这些列表添加事件处理的功能。另外,这个Builder类将AlertDialog对话框上的3个按钮按照他们的位置分别称呼为:PositiveButton, NeutralButton, NegativeButton。

(2)ProgressDialog

ProgressDialog.dialog = new ProgressDialog(context); 没有内部静态类,直接构造函数构造

 

3. 一个很特别的Dialog(由Activity转换而来) ,具体请参见参考doc中android.R.style部分
(1)AndroidManifest.xml中的activity的属性中增加:android :theme="@android :style/Theme.Dialog( Activity的对话框主题)。可使Activity变为Dialog(浮动窗口);
(2)AndroidManifest.xml中的activity的属性中增加:android:theme="@android:style/Theme.Translucent"(Activity半透明主题);

 

4. 示例代码

(1)自定义Dialog并获取Dialog中EditText的数据

public class MyDialog extends Dialog implements Button.OnClickListener {
	private Button okButton, cancelButton;
    private EditText nameEditText;
    private MyDialogListener listener;
    
	public MyDialog(Context context, MyDialogListener listener) {
		super(context);
        this.listener = listener;
	}
	protected void onCreate(Bundle savedInstanceState) {
		setContentView(R.layout.mydialog);
		
		okButton = (Button) findViewById(R.id.okButton);
        cancelButton = (Button) findViewById(R.id.cancelButton);
        okButton.setOnClickListener(this);
        cancelButton.setOnClickListener(this);
        
        nameEditText = (EditText) findViewById(R.id.nameEditText);
	}
	public void onClick(View v) {
		switch (v.getId()) {
        case R.id.okButton:
        	 listener.onOkClick(nameEditText.getText().toString());
             dismiss(); // 关闭Dialog
             break;
        case R.id.cancelButton:
        	 cancel(); // 取消Dialog, "取消"的含义是指不再需要执行对话框上的任何功能和动作, 取消对话框会自动调用dismiss()方法
             break;
		}
		/*
		 * 当用户点击手机设备上的“返回”按钮时,屏幕上的对话框将会被取消,
		 * 如果你想让你的对话框不在这种情况下被取消掉的话,你可以如下设置你的对话框:setCancelable(false);
		 * 对话框的取消和关闭事件可以通过OnCancelListener和OnDismissListener两个监听器来被监听处理。
		 */
	}
	
}
 
public class MainActivity extends Activity implements MyDialogListener {
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        MyDialog dialog = new MyDialog(this, this);
        dialog.show();
    }
	public void onCancelClick() {
	}
	public void onOkClick(String name) {
		Toast.makeText(this, name, Toast.LENGTH_LONG).show();
	}
}

interface MyDialogListener {
    public void onOkClick(String name);
    public void onCancelClick();
}

 

mydialog.xml

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:orientation="vertical">
	<TextView
		android:id="@+id/nameMessage"
	    android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Enter Name:"></TextView>
        <EditText
        	android:id="@+id/nameEditText"
       		android:layout_width="fill_parent"
       		android:layout_height="wrap_content"
       		android:textSize="18sp"></EditText>
       	<LinearLayout
           	android:id="@+id/buttonLayout"
       		android:layout_width="fill_parent"
       		android:layout_height="wrap_content"
       		android:layout_gravity="center_horizontal">
       		<Button
            	android:id="@+id/okButton"
        		android:layout_width="wrap_content"
        		android:layout_height="wrap_content"
        		android:text="OK">
        	</Button>
        	<Button
             	android:id="@+id/cancelButton"
        		android:layout_width="wrap_content"
          		android:layout_height="wrap_content"
          		android:text="Cancel">
          	</Button>
     </LinearLayout>
</LinearLayout>

 

(2)

public class MainActivity2 extends Activity {
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        AlertDialog dialog = new AlertDialog.Builder(this).create();
        dialog.setMessage("Do you play cricket?");
        dialog.setButton("Yes", new DialogInterface.OnClickListener() {
			public void onClick(DialogInterface dialog, int which) {
				switch (which) {
		        case AlertDialog.BUTTON1:
		        	break;
		        case AlertDialog.BUTTON2:
		            break;
				}
			}
        });
        dialog.setButton2("No", new DialogInterface.OnClickListener() {
			public void onClick(DialogInterface dialog, int which) {
			}
        });
        dialog.show();
    }
}

 

(3)托管Dialog

public class MainActivity extends Activity {
	private Button button1, button2, button3, button4;
	private Button.OnClickListener listener1, listener2, listener3, listener4;
	private final int DIALOG1 = 1, DIALOG2 = 2, DIALOG3 = 3, DIALOG4 = 4;
	
	@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        prepareListener();
    }
	
	protected Dialog onCreateDialog(int id) {
		switch (id) {
		case DIALOG1:
			return buildDialog(this, DIALOG1);
		case DIALOG2:
			return buildDialog(this, DIALOG2);
		case DIALOG3:
			return buildDialog(this, DIALOG3);
		case DIALOG4:
			return buildDialog(this, DIALOG4);
		}
		return null;
	}
	
	protected void onPrepareDialog(int id, Dialog dialog) {
		super.onPrepareDialog(id, dialog);
	}
	
	private Dialog buildDialog(Context context, int seq) {
		AlertDialog.Builder builder = new AlertDialog.Builder(context);
		builder.setIcon(R.drawable.alert_dialog_icon);
		if (DIALOG1 == seq) {
			builder.setTitle(R.string.alert_dialog_two_buttons_title);
			builder.setPositiveButton(R.string.alert_dialog_ok, new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface dialog, int which) {
					setTitle(R.string.alert_dialog_ok);
				}
			});
			builder.setNegativeButton(R.string.alert_dialog_cancel, new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface dialog, int which) {
					setTitle(R.string.alert_dialog_cancel);
				}
			});
		}
		if (DIALOG2 == seq) {
			builder.setTitle(R.string.alert_dialog_two_buttons_msg);
			builder.setMessage(R.string.alert_dialog_two_buttons2_msg);
			
			// AlertDialog最多只能有3个Button
			builder.setPositiveButton(R.string.alert_dialog_ok, new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface dialog, int which) {
					setTitle(R.string.alert_dialog_ok);
				}
			});
			builder.setNeutralButton(R.string.alert_dialog_something, new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface dialog, int which) {
					setTitle(R.string.alert_dialog_something);
				}
			});
			builder.setNegativeButton(R.string.alert_dialog_cancel, new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface dialog, int which) {
					setTitle(R.string.alert_dialog_cancel);
				}
			});
		}
		if (DIALOG3 == seq) {
			// LayoutInflater的inflate方法可以将一个XML布局变成一个View实例
			LayoutInflater inflater = LayoutInflater.from(this);
			View textEntryView = inflater.inflate(R.layout.alert_dialog_text_entry, null);
			builder.setTitle(R.string.alert_dialog_text_entry);
			
			// setView()真可以说是Dialog的一个精髓
			builder.setView(textEntryView);
			builder.setPositiveButton(R.string.alert_dialog_ok, new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface dialog, int which) {
					setTitle(R.string.alert_dialog_ok);
				}
			});
			builder.setNegativeButton(R.string.alert_dialog_cancel, new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface dialog, int which) {
					setTitle(R.string.alert_dialog_cancel);
				}
			});
		}
		if (DIALOG4 == seq) {
			ProgressDialog dialog = new ProgressDialog(context);
			dialog.setTitle("Downding the songs...");
			dialog.setMessage("Please Waiting...");
			return dialog;
		}
		return builder.create();
	}

	private boolean prepareListener() {
		// init button
		button1 = (Button) findViewById(R.id.button1);
        button2 = (Button) findViewById(R.id.button2);
        button3 = (Button) findViewById(R.id.button3);
        button4 = (Button) findViewById(R.id.button4);
        
        // init listener
		listener1 = new Button.OnClickListener() {
			public void onClick(View v) {
				showDialog(DIALOG1);
			}
		};
		listener2 = new Button.OnClickListener() {
			public void onClick(View v) {
				showDialog(DIALOG2);
			}
		};
		listener3 = new Button.OnClickListener() {
			public void onClick(View v) {
				showDialog(DIALOG3);
			}
		};
		listener4 = new Button.OnClickListener() {
			public void onClick(View v) {
				showDialog(DIALOG4);
			}
		};
		
		// bind listener
		button1.setOnClickListener(listener1);
        button2.setOnClickListener(listener2);
        button3.setOnClickListener(listener3);
        button4.setOnClickListener(listener4);
		return true;
	}
}

 

alert_dialog_text_entry.xml

<?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"
    >
    <!-- android:textAppearance:设置字体, 系统自带的字体 -->
    <!-- android:capitalize:设置大小写;none首字母小写;words首字母大写 -->
    <TextView android:id="@+id/username_view"
    	android:layout_width="wrap_content"
    	android:layout_height="wrap_content"
    	android:layout_marginLeft="20dip"
    	android:layout_marginRight="20dip"
    	android:text="用户名"
    	android:textAppearance="?android:attr/textAppearanceMedium"
    />
    <EditText android:id="@+id/username_edit"
    	android:layout_width="fill_parent"
    	android:layout_height="wrap_content"
    	android:layout_marginLeft="20dip"
    	android:layout_marginRight="20dip"
    	android:capitalize="words"
    	android:textAppearance="?android:attr/textAppearanceMedium"
    />
    <TextView android:id="@+id/password_view"
    	android:layout_width="wrap_content"
    	android:layout_height="wrap_content"
    	android:layout_marginLeft="20dip"
    	android:layout_marginRight="20dip"
    	android:text="密码"
    	android:textAppearance="?android:attr/textAppearanceMedium"
    />
    <EditText android:id="@+id/password_edit"
    	android:layout_width="fill_parent"
    	android:layout_height="wrap_content"
    	android:layout_marginLeft="20dip"
    	android:layout_marginRight="20dip"
    	android:capitalize="none"
    	android:password="true"
    	android:textAppearance="?android:attr/textAppearanceMedium"
    />
</LinearLayout>

 

5.

分享到:
评论
3 楼 再_见孙悟空 2014-02-04  
写的不错
2 楼 zx273064010 2011-02-15  
                   
1 楼 hezhou_0521 2010-11-30  
如果把相应该的效果图附上,那多好啊。

相关推荐

Global site tag (gtag.js) - Google Analytics