Android笔记(七十) AlertDialog

alertdialog可以在当前界面中弹出一个对话框，这个对话框在界面所有元素之上，可以屏蔽掉其他控件的交互能力，因此alertdialog常用于一些重要的内容警告。

使用AlertDialog.Builder创建对话框需要了解以下几个方法：

setTitle ：为对话框设置标题

setIcon ：为对话框设置图标

setMessage：为对话框设置内容

setView ： 给对话框设置自定义样式

setItems ：设置对话框要显示的一个list，一般用于显示几个命令时

setMultiChoiceItems ：用来设置对话框显示一系列的复选框

setNeutralButton ：普通按钮

setPositiveButton ：给对话框添加"Yes"按钮

setNegativeButton ：对话框添加"No"按钮

setCancelable：点击其他部位是否可以取消alertdialog，默认为true

setSingleChoiceItems：设置类似于单选框一样的list

create ： 创建对话框

show ：显示对话框

普通的AlertDialog：

package com.example.alertdialogdemo;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

private Button bt;
private TextView tv;
private Context mContext;

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

mContext = MainActivity.this;

bt = (Button) findViewById(R.id.bt);
tv = (TextView) findViewById(R.id.tv);
bt.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setCancelable(false);
dialog.setIcon(R.drawable.remind);
dialog.setTitle("This is title!");
dialog.setMessage("This is Message!");
dialog.setPositiveButton("YES", new OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(mContext, "YES→" + which, Toast.LENGTH_SHORT).show();
changeText(which);
}
});
dialog.setNegativeButton("NO", new OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(mContext, "NO→" + which, Toast.LENGTH_SHORT).show();
changeText(which);
}
});

dialog.show();
}
});
}

public void changeText(int which) {
if (which == -1) {
tv.setText("您选择的是YES！");
} else if (which == -2) {
tv.setText("您选择的是NO！");
}
}
}

运行结果：







　　

类似ListView的AlertDialog

package com.example.alertdialogdemo;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

private Button bt;
private TextView tv;
private Context mContext;
private String[] phones = { "三星", "苹果", "小米", "魅族", "锤子", "华为", "中兴" };

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mContext = MainActivity.this;
bt = (Button) findViewById(R.id.bt);
tv = (TextView) findViewById(R.id.tv);
bt.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setCancelable(true);
dialog.setIcon(R.drawable.phone);
dialog.setTitle("选择你喜欢的手机");
dialog.setItems(phones, new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
changeText(which);
}
});
dialog.show();
}
});
}

public void changeText(int which) {
tv.setText("您选择的手机是： " + phones[which]);
}
}

运行结果：





单选AlertDialog

package com.example.alertdialogdemo;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

private Button bt;
private TextView tv;
private Context mContext;
private String[] sex = { "男生", "女生", "雌雄同体" };

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

mContext = MainActivity.this;

bt = (Button) findViewById(R.id.bt);
tv = (TextView) findViewById(R.id.tv);
bt.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setCancelable(true);
dialog.setIcon(R.drawable.phone);
dialog.setTitle("你的性别：");
// 第二个参数是默认选择位置
dialog.setSingleChoiceItems(sex, 0, new OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
changeText(which);
}
});
dialog.setPositiveButton("OK", new OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {

}
});
dialog.show();
}
});
}

public void changeText(int which) {
tv.setText("您的性别是： " + sex[which]);
}
}

运行结果：





多选AlertDialog

package com.example.alertdialogdemo;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.DialogInterface.OnMultiChoiceClickListener;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

private Button bt;
private TextView tv;
private Context mContext;
private String[] hobby = { "看电影", "看书", "上网", "篮球", "足球", "游泳", "逛街", "羽毛球" };
private List<String> hobbyList;

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

mContext = MainActivity.this;

hobbyList = new ArrayList<String>();

bt = (Button) findViewById(R.id.bt);
tv = (TextView) findViewById(R.id.tv);
bt.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setCancelable(true);
dialog.setIcon(R.drawable.heart);
dialog.setTitle("你的性别：");

dialog.setMultiChoiceItems(hobby, null, new OnMultiChoiceClickListener() {

@Override
public void onClick(DialogInterface dialog, int which, boolean isChecked) {
hobbyList.add(hobby[which]);

}
});

dialog.setPositiveButton("OK", new OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
changeText();
}
});
dialog.show();
}
});
}

public void changeText(int which) {

}

public void changeText() {
String str = "";

for (int i = 0; i < hobbyList.size(); i++) {
str = hobbyList.get(i) + " " + str;
}

tv.setText("您的爱好有： " + str);
}
}

运行结果：





自定义AlertDialog

MainActivity.java

package com.example.alertdialogdemo;

import java.util.ArrayList;
import java.util.List;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

@SuppressLint("NewApi")
public class MainActivity extends Activity {

private Button bt;
private TextView tv;
private Context mContext;
private View view;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mContext = MainActivity.this;
bt = (Button) findViewById(R.id.bt);
tv = (TextView) findViewById(R.id.tv);
bt.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
view = LayoutInflater.from(mContext).inflate(R.layout.custom_view_dialog, null);
dialog.setCancelable(true);
dialog.setTitle("你的身高：");
dialog.setView(view);
dialog.setPositiveButton("OK", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
changeText();
}
});
dialog.show();
}
});
}
public void changeText() {
EditText et = (EditText) view.findViewById(R.id.height);
String height = et.getText().toString().trim();
tv.setText("身高：" + height + " cm");
}
}

custom_view_dialog.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ruler" />

<EditText
android:id="@+id/height"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="cm" />

</LinearLayout>

运行效果：