2015-06-22

android

对话框的父类--AlertDialog

一.普通的AlertDialog:

1.AlertDialog的结构:

2.如何创建一个AlertDialog对象:

步骤:

3.代码实现:

布局只有一个按钮,比较简单,这里就略过了

MainActivity.java

public class MainActivity extends Activity {  
  
    private Button btnshow;  
    private AlertDialog.Builder build = null;  
    private AlertDialog alert = null;  
      
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
          
        btnshow = (Button) findViewById(R.id.btnshow);  
        btnshow.setOnClickListener(new View.OnClickListener() {  
              
            @Override  
            public void onClick(View v) {  
                //1.创建一个AlertDialog.Builder对象  
                alert = new AlertDialog.Builder(MainActivity.this).create();  
                //当然这里也可以这样写:build = new AlertDialog.Builder(getApplicationContext());  
                //这里的话要在后面.set***吧属性设好  
                  
                //2.设置图标,标题,内容  
                alert.setIcon(R.drawable.kabi);  
                alert.setTitle("系统提示:");  
                alert.setMessage("这是一个普通的AlertDialog,\n依次有取消,中立,确定按钮");  
                  
                //3.设置三个按钮,可以两个或者一个,最多只能设置三个按钮哦  
                //确定按钮:  
                  alert.setButton(DialogInterface.BUTTON_POSITIVE, "确定", new DialogInterface.OnClickListener() {  
                    @Override  
                    public void onClick(DialogInterface dialog, int which) {  
                        Toast.makeText(getApplicationContext(), "你点击了确定按钮", Toast.LENGTH_SHORT).show();  
                    }  
                });  
                  alert.setButton(DialogInterface.BUTTON_NEGATIVE, "取消", new DialogInterface.OnClickListener() {  
                    @Override  
                    public void onClick(DialogInterface dialog, int which) {  
                        Toast.makeText(getApplicationContext(), "你点击了取消按钮", Toast.LENGTH_SHORT).show();  
                          
                    }  
                });  
                  alert.setButton(DialogInterface.BUTTON_NEUTRAL, "中立", new DialogInterface.OnClickListener() {  
                    @Override  
                    public void onClick(DialogInterface dialog, int which) {  
                        Toast.makeText(getApplicationContext(), "你点击了中立按钮", Toast.LENGTH_SHORT).show();  
                    }  
                }); 
                
                //4.调用show()方法把AlertDialog显示出来  
                alert.show();    
            }  
        });  
    }  
}

运行结果:

代码解释:

1.这里的话我们是直接通过新建一个AlertDialog.Builder对象,同时调用create()方法创建了一个AlertDialog对象

2.这里要注意哦,普通按钮的监听器对象为View.OnClickListener,而AlertDialog的按钮监听器对象为DialogInterface.OnClickListener

3.按钮的话最多只能有三个,可以一个或者两个,确定,中立,取消按钮,setButton();第一个参数是决定了是哪种按钮:都是DialogInterface.****

BUTTON_POSITIVE:确定按钮 BUTTON_NEGATIVE:取消按钮 BUTTON_NEUTRAL:中立按钮

4.这里还要注意一点很容易出错的,就是

很容易出现以下错误:

android.view.WindowManager$BadTokenException: Unable to add window – token null is not for an application
或：java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity

这里的话是因为AlertDialog alert = new AlertDialog.Builder(MainActivity.this).create();

里面的这个MainActivity必须写成当前的Activity.this,不能够用getApplicationContext(),或者直接this,都会报错的哦！

源码链接:http://pan.baidu.com/s/1BZPo2

二.设置一个带列表,单选列表,多选列表的对话框

这里为了方便,就把三种对话框的实现放到一起了,这里通过三个按钮弹出对应的窗体。

代码:

main.xml布局文件就只有三个按钮,并为其设置id

MainActivity.java

public class MainActivity extends Activity {  
      
    private Button btnlist;  
    private Button btnradio;  
    private Button btncheck;  
    private AlertDialog alert = null;  
    private AlertDialog.Builder builder = null;  
    private boolean[] checkItems;  
      
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
          
        btnlist = (Button) findViewById(R.id.btnlist);  
        btnradio = (Button) findViewById(R.id.btnradio);  
        btncheck = (Button) findViewById(R.id.btncheck);  
          
          
        //1.这个按钮时触发一个带普通列表的AlertDialog  
        btnlist.setOnClickListener(new View.OnClickListener() {       
            @Override  
            public void onClick(View v) {  
                final String[] lesson = new String[]{"语文","数学","英语","化学","生物","物理","体育"};  
                builder = new AlertDialog.Builder(MainActivity.this);  
                builder.setIcon(R.drawable.yibu);  
                builder.setTitle("请选择你喜欢的课程");  
                builder.setItems(lesson, new DialogInterface.OnClickListener() {  
                      
                    @Override  
                    public void onClick(DialogInterface dialog, int which) {  
                        Toast.makeText(getApplicationContext(), "你选择了"+lesson[which],Toast.LENGTH_SHORT).show();  
                    }  
                });  
                alert = builder.create();  
                alert.show();  
            }  
        });  
          
        //2.这个按钮是触发一个带单选列表的AlertDialog  
        btnradio.setOnClickListener(new View.OnClickListener() {  
              
            @Override  
            public void onClick(View v) {  
                final String[] fruits = new String[]{"苹果","雪梨","香蕉","葡萄","西瓜"};  
                builder = new AlertDialog.Builder(MainActivity.this);  
                builder.setIcon(R.drawable.leiyibu);  
                builder.setTitle("请选择你喜欢的水果,只能选一个哦!");  
                builder.setSingleChoiceItems(fruits, 0, new DialogInterface.OnClickListener() {  
                      
                    @Override  
                    public void onClick(DialogInterface dialog, int which) {  
                        Toast.makeText(getApplicationContext(), "你选择了"+fruits[which], Toast.LENGTH_SHORT).show();  
                    }  
                });  
                builder.setPositiveButton("确定", null);  
                alert = builder.create();  
                alert.show();  
            }  
        });  
          
        //3.这个按钮时触发一个带多选按钮的AlertDialog  
        btncheck.setOnClickListener(new View.OnClickListener() {  
              
            @Override  
            public void onClick(View v) {  
                final String[] menu = new String[]{"水煮豆腐","萝卜牛腩","葱爆瘦肉"};  
                //定义一个用来记录个列表项状态的boolean数组  
                checkItems = new boolean[]{false,false,false};  
                  
                builder = new AlertDialog.Builder(MainActivity.this);  
                builder.setIcon(R.drawable.huoyibu);  
                builder.setTitle("点选你喜欢的菜肴:");  
                builder.setMultiChoiceItems(menu, checkItems, new OnMultiChoiceClickListener() {  
                      
                    @Override  
                    public void onClick(DialogInterface dialog, int which, boolean isChecked) {  
                        // TODO Auto-generated method stub  
                        checkItems[which] = isChecked;  
                    }  
                });  
                //为对话框添加确定按钮:  
                builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {  
                      
                    @Override  
                    public void onClick(DialogInterface dialog, int which) {  
                        String result = "";  
                        for(int i = 0;i < checkItems.length;i++)  
                        {  
                            if(checkItems[i])  
                                result += menu[i]+" ";  
                        }  
                        Toast.makeText(getApplicationContext(),"客官你点了:"+result, Toast.LENGTH_SHORT).show();  
                    }  
                });  
                  
                builder.create().show();  
            }  
        });  
    }  
}

运行截图:

代码解释:

1.这几个的区别主要是设置内容那里,普通的是setItem()；单选按钮时setSingleChoiceItems；复选框是setMultiChoiceItems();

2.这里的setOnClickListener 是DialogInterface.OnClickListener,而非View的那个

3.第三个复选框我们是通过boolean数组判断是否选中的,确定按钮中的触发事件是:OnMultiChoiceClickListener,参数依次为显示的数组,boolean的状态数组

4.boolean写成Boolean是会报错的哦！！！！

源码下载:http://pan.baidu.com/s/1y2FlK

三.自定义一个AlertDialog:

main.xml中只定义一个简单的按钮

首先,自定义一个我们想要的布局,我们这里做的是一个登陆的布局

<?xml version="1.0" encoding="utf-8"?>  
    <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"  
        android:layout_width="match_parent"  
        android:layout_height="match_parent"  
        android:orientation="vertical" >  
        <TableRow>  
            <TextView  
                android:layout_width="match_parent"  
                android:layout_height="wrap_content"  
                android:text="账号:"  
                android:textSize="15sp"  
            />  
            <EditText   
                android:id="@+id/txtname"  
                android:layout_width="match_parent"  
                android:layout_height="wrap_content"  
                android:hint="请输入您的账号:     "  
                android:selectAllOnFocus="true"  
            />  
        </TableRow>  
        <TableRow>  
            <TextView  
                android:layout_width="match_parent"  
                android:layout_height="wrap_content"  
                android:text="密码:"  
                android:textSize="12sp"  
            />  
            <EditText   
                android:id="@+id/txtpassword"  
                android:layout_width="match_parent"  
                android:layout_height="wrap_content"  
                android:hint="请输入您的密码:    "  
                android:password="true"  
            />  
        </TableRow>  
    </TableLayout>

解释:这些属性在前面的组件都有的,不会的可以查看前面的博文

接着,就是MainActivity.java,其实自定义和普通的区别就是用了setView方法,我们只需要为login布局创建一个view即可

这里的话用到inflate动态加载布局

代码如下:

public class MainActivity extends Activity {  
      
    private Button btnshow;  
    private AlertDialog.Builder build = null;  
    private EditText edit;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
          
        btnshow = (Button) findViewById(R.id.btnshow);  
        btnshow.setOnClickListener(new OnClickListener() {  
              
            @Override  
            public void onClick(View v) {  
                TableLayout table = (TableLayout) getLayoutInflater().inflate(R.layout.login, null);  
                edit = (EditText) table.findViewById(R.id.txtname);  
                build = new AlertDialog.Builder(MainActivity.this);  
                build.setIcon(R.drawable.pipi);  
                build.setTitle("登陆界面:");  
                build.setView(table);  
                build.setPositiveButton("登陆", new DialogInterface.OnClickListener() {  
                      
                    @Override  
                    public void onClick(DialogInterface dialog, int which) {  
                        Toast.makeText(getApplicationContext(), "欢迎你"+edit.getText(), Toast.LENGTH_SHORT).show();  
                    }  
                });  
                build.setNegativeButton("取消", new DialogInterface.OnClickListener() {  
                      
                    @Override  
                    public void onClick(DialogInterface dialog, int which) {  
                        Toast.makeText(getApplicationContext(), "感谢您的使用!", Toast.LENGTH_SHORT).show();  
                    }  
                });  

                build.create().show();  
            }  
        });  
    }  
}

运行截图:

代码解释:

1.这里的话要注意动态加载布局那里:
TableLayout table = (TableLayout) getLayoutInflater().inflate(R.layout.login, null);
edit = (EditText) table.findViewById(R.id.txtname);

因为我们想获取的是login的布局中的EditText的文本内容,这里findViewByid的话要在前面加上这个动态布局的table.FindViewById.不然会报空指针异常

2.再次说明一下,我们自定义布局的核心是Builder类的setView()方法,只要实例化一个View放进去即可

程序源码:http://pan.baidu.com/s/1ziCsP

转自：http://blog.csdn.net/coder_pig/article/details/16828579