提要
本节继续给大家带来是显示提示信息的第三个控件AlertDialog(对话框),同时它也是其他Dialog的的父类!比如ProgressDialog,TimePickerDialog等,而AlertDialog的父类是:Dialog!另外,不像前面学习的Toast和Notification,AlertDialog并不能直接new出来,如果你打开AlertDialog的源码,会发现构造方法是protected的,如果我们要创建AlertDialog的话,我们需要使用到该类中的一个静态内部类:public static class Builder,然后来调用AlertDialog里的相关方法,来对AlertDialog进行定制,最后调用show()方法来显示我们的AlertDialog对话框!
1.基本使用流程
- Step 1:创建AlertDialog.Builder对象;
- Step 2:调用setIcon() 设置图标,setTitle() 或setCustomTitle() 设置标题;
- Step 3:设置对话框的内容:setMessage() 还有其他方法来指定显示的内容;
- Step 4:调用setPositive/Negative/NeutralButton() 设置:确定,取消,中立按钮;
- Step 5:调用create() 方法创建这个对象,再调用show() 方法将对话框显示出来;
2.几种常用的对话框使用示例
运行效果图:
核心代码:
MainActivity.java:
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public class MainActivity extends AppCompatActivity implements View.OnClickListener { private Button btn_dialog_one; private Button btn_dialog_two; private Button btn_dialog_three; private Button btn_dialog_four; private Context mContext; private boolean [] checkItems; private AlertDialog alert = null ; private AlertDialog.Builder builder = null ; @Override protected void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState); setContentView(R.layout.activity_main); mContext = MainActivity. this ; bindView(); } private void bindView() { btn_dialog_one = (Button) findViewById(R.id.btn_dialog_one); btn_dialog_two = (Button) findViewById(R.id.btn_dialog_two); btn_dialog_three = (Button) findViewById(R.id.btn_dialog_three); btn_dialog_four = (Button) findViewById(R.id.btn_dialog_four); btn_dialog_one.setOnClickListener( this ); btn_dialog_two.setOnClickListener( this ); btn_dialog_three.setOnClickListener( this ); btn_dialog_four.setOnClickListener( this ); } @Override public void onClick(View v) { switch (v.getId()) { //普通对话框 case R.id.btn_dialog_one: alert = null ; builder = new AlertDialog.Builder(mContext); alert = builder.setIcon(R.mipmap.ic_icon_fish) .setTitle( "系统提示:" ) .setMessage( "这是一个最普通的AlertDialog, 带有三个按钮,分别是取消,中立和确定" ) .setNegativeButton( "取消" , new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { Toast.makeText(mContext, "你点击了取消按钮~" , Toast.LENGTH_SHORT).show(); } }) .setPositiveButton( "确定" , new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { Toast.makeText(mContext, "你点击了确定按钮~" , Toast.LENGTH_SHORT).show(); } }) .setNeutralButton( "中立" , new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { Toast.makeText(mContext, "你点击了中立按钮~" , Toast.LENGTH_SHORT).show(); } }).create(); //创建AlertDialog对象 alert.show(); //显示对话框 break ; //普通列表对话框 case R.id.btn_dialog_two: final String[] lesson = new String[]{ "语文" , "数学" , "英语" , "化学" , "生物" , "物理" , "体育" }; alert = null ; builder = new AlertDialog.Builder(mContext); alert = builder.setIcon(R.mipmap.ic_icon_fish) .setTitle( "选择你喜欢的课程" ) .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(); } }).create(); alert.show(); break ; //单选列表对话框 case R.id.btn_dialog_three: final String[] fruits = new String[]{ "苹果" , "雪梨" , "香蕉" , "葡萄" , "西瓜" }; alert = null ; builder = new AlertDialog.Builder(mContext); alert = builder.setIcon(R.mipmap.ic_icon_fish) .setTitle( "选择你喜欢的水果,只能选一个哦~" ) .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(); } }).create(); alert.show(); break ; //多选列表对话框 case R.id.btn_dialog_four: final String[] menu = new String[]{ "水煮豆腐" , "萝卜牛腩" , "酱油鸡" , "胡椒猪肚鸡" }; //定义一个用来记录个列表项状态的boolean数组 checkItems = new boolean []{ false , false , false , false }; alert = null ; builder = new AlertDialog.Builder(mContext); alert = builder.setIcon(R.mipmap.ic_icon_fish) .setMultiChoiceItems(menu, checkItems, new DialogInterface.OnMultiChoiceClickListener() { @Override public void onClick(DialogInterface dialog, int which, boolean isChecked) { checkItems[which] = isChecked; } }) .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(); } }) .create(); alert.show(); break ; } } } |
布局就是四个简单的按钮,这里就不贴出来了,用法非常简单~无非就是创建一个Builder对象后,进行相关设置,然后create()生成一个AlertDialog对象,最后调用show()方法将AlertDialog显示出来而已!另外,细心的你可能发现我们点击对话框的外部区域,对话框就会消失,我们可以为builder设置setCancelable(false) 即可解决这个问题!
3.通过Builder的setView()定制显示的AlertDialog
我们可以自定义一个与系统对话框不同的布局,然后调用setView()将我们的布局加载到AlertDialog上,上面我们来实现这个效果:
运行效果图:
关键代码:
首先是两种不同按钮的selctor的drawable文件:
btn_selctor_exit.xml:
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<? xml version = "1.0" encoding = "utf-8" ?> < selector xmlns:android = "http://schemas.android.com/apk/res/android" > < item android:state_pressed = "true" android:drawable = "@mipmap/iv_icon_exit_pressed" /> < item android:drawable = "@mipmap/iv_icon_exit_normal" /> </ selector > |
btn_selctor_choose.xml:
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<? xml version = "1.0" encoding = "utf-8" ?> < selector xmlns:android = "http://schemas.android.com/apk/res/android" > < item android:state_pressed = "true" android:drawable = "@mipmap/bg_btn_pressed" /> < item android:drawable = "@mipmap/bg_btn_normal" /> </ selector > |
接着是自定义的Dialog布局:view_dialog_custom.xml:
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<? xml version = "1.0" encoding = "utf-8" ?> < RelativeLayout xmlns:android = "http://schemas.android.com/apk/res/android" android:id = "@+id/RelativeLayout1" android:layout_width = "match_parent" android:layout_height = "match_parent" android:orientation = "vertical" > < RelativeLayout android:id = "@+id/titlelayout" android:layout_width = "match_parent" android:layout_height = "wrap_content" android:layout_alignParentLeft = "true" android:layout_alignParentTop = "true" android:background = "#53CC66" android:padding = "5dp" > < TextView android:layout_width = "match_parent" android:layout_height = "wrap_content" android:layout_centerVertical = "true" android:text = "提示信息" android:textColor = "#ffffff" android:textSize = "18sp" android:textStyle = "bold" /> < Button android:id = "@+id/btn_cancle" android:layout_width = "30dp" android:layout_height = "30dp" android:layout_alignParentRight = "true" android:background = "@drawable/btn_selctor_exit" /> </ RelativeLayout > < LinearLayout android:id = "@+id/ly_detail" android:layout_width = "wrap_content" android:layout_height = "wrap_content" android:layout_alignParentLeft = "true" android:layout_below = "@+id/titlelayout" android:layout_centerInParent = "true" android:orientation = "vertical" > < TextView android:layout_width = "wrap_content" android:layout_height = "wrap_content" android:layout_marginLeft = "10dp" android:layout_marginTop = "20dp" android:text = "通过setView()方法定制AlertDialog" android:textColor = "#04AEDA" android:textSize = "18sp" /> < TextView android:layout_width = "wrap_content" android:layout_height = "wrap_content" android:layout_marginLeft = "10dp" android:layout_marginTop = "10dp" android:text = "作者:Coder-pig" android:textColor = "#04AEDA" android:textSize = "18sp" /> </ LinearLayout > < LinearLayout android:layout_width = "match_parent" android:layout_height = "wrap_content" android:layout_below = "@+id/ly_detail" android:layout_marginTop = "10dp" android:orientation = "horizontal" > < Button android:id = "@+id/btn_blog" android:layout_width = "match_parent" android:layout_height = "40dp" android:layout_margin = "5dp" android:layout_weight = "1" android:background = "@drawable/btn_selctor_choose" android:text = "访问博客" android:textColor = "#ffffff" android:textSize = "20sp" /> < Button android:id = "@+id/btn_close" android:layout_width = "match_parent" android:layout_height = "40dp" android:layout_margin = "5dp" android:layout_weight = "1" android:background = "@drawable/btn_selctor_choose" android:text = "关闭" android:textColor = "#ffffff" android:textSize = "20sp" /> </ LinearLayout > </ RelativeLayout > |
最后是MainActivity.java:
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public class MainActivity extends AppCompatActivity { private Button btn_show; private View view_custom; private Context mContext; private AlertDialog alert = null ; private AlertDialog.Builder builder = null ; @Override protected void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState); setContentView(R.layout.activity_main); mContext = MainActivity. this ; btn_show = (Button) findViewById(R.id.btn_show); //初始化Builder builder = new AlertDialog.Builder(mContext); //加载自定义的那个View,同时设置下 final LayoutInflater inflater = MainActivity. this .getLayoutInflater(); view_custom = inflater.inflate(R.layout.view_dialog_custom, null , false ); builder.setView(view_custom); builder.setCancelable( false ); alert = builder.create(); view_custom.findViewById(R.id.btn_cancle).setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { alert.dismiss(); } }); view_custom.findViewById(R.id.btn_blog).setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { Toast.makeText(getApplicationContext(), "访问博客" , Toast.LENGTH_SHORT).show(); Uri uri = Uri.parse( "http://blog.csdn.net/coder_pig" ); Intent intent = new Intent(Intent.ACTION_VIEW, uri); startActivity(intent); alert.dismiss(); } }); view_custom.findViewById(R.id.btn_close).setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { Toast.makeText(getApplicationContext(), "对话框已关闭~" , Toast.LENGTH_SHORT).show(); alert.dismiss(); } }); btn_show.setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { alert.show(); } }); } } |
以上就是提示信息控件AlertDialog对话框详解的详细内容,更多关于AlertDialog 对话框的资料请关注服务器之家其它相关文章!
原文链接:https://juejin.cn/post/7221142609518657595