xamarin android alertdialog详解
说明一下：学习xamarin android一段时间，准备写一些xamarin android相关的例子，alertdialog也是使用的非常多得空间之一，非常感谢鸟巢上的小猪，我也是看着他写的教程学会的。参考他的那一章 http://www.runoob.com/w3cnote/android-tutorial-alertdialog.html
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： 
主要代码：MainActivity.class
public class MainActivity : Activity
{
int count = 1;
private Button btn_alertDialog_one, btn_alertDialog_two, btn_alertDialog_three, btn_alertDialog_four;
private bool[] checkItems;
private AlertDialog alertDialog = null;
private AlertDialog.Builder builder = null;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
bindViewClick();
}
private void bindViewClick()
{
btn_alertDialog_four = FindViewById<Button>(Resource.Id.btn_alertDialog_four);
btn_alertDialog_three = FindViewById<Button>(Resource.Id.btn_alertDialog_three);
btn_alertDialog_two = FindViewById<Button>(Resource.Id.btn_alertDialog_two);
btn_alertDialog_one = FindViewById<Button>(Resource.Id.btn_alertDialog_one);
btn_alertDialog_one.Click += delegate { onClick(btn_alertDialog_one); };
btn_alertDialog_two.Click += delegate { onClick(btn_alertDialog_two); };
btn_alertDialog_three.Click += delegate { onClick(btn_alertDialog_three); };
btn_alertDialog_four.Click += delegate { onClick(btn_alertDialog_four); };
}
private void onClick(View v)
{
switch (v.Id)
{
case Resource.Id.btn_alertDialog_one:
alertDialog = null;
builder = new AlertDialog.Builder(this);
alertDialog = builder
.SetTitle("sure")
.SetMessage("are you sure exit?")
.SetNegativeButton("cancel", (s, e) =>
{
Toast.MakeText(this, "you click cancel", ToastLength.Short).Show();
})
.SetPositiveButton("sure", (s, e) =>
{
Toast.MakeText(this, "you click sure", ToastLength.Short).Show();
})
.SetNeutralButton("neutra", (s, e) => {
Toast.MakeText(this, "you click neutra", ToastLength.Short).Show();
})
.Create(); //创建alertDialog对象
alertDialog.Show();
var dialog = new AlertDialog.Builder(this);
break;
case Resource.Id.btn_alertDialog_two:
alertDialog = null;
builder = new AlertDialog.Builder(this);
string[] players = new string[] {"杜兰特","汤普森","考辛斯","卡戴珊"};
alertDialog = builder
.SetIcon(Resource.Drawable.players)
.SetTitle("选择你喜欢的球员")
.SetItems(players, (s, e) =>
{
Toast.MakeText(this, "you selected " + players[e.Which], ToastLength.Short).Show();
})
.Create();
alertDialog.Show();
break;
case Resource.Id.btn_alertDialog_three:
var a = new AlertDialog.Builder(this);
string[] teams = new string[] {"骑士","公牛","快船","马刺","勇士" };
a.SetTitle("你认为下个赛季哪只球队能夺冠")
.SetSingleChoiceItems(teams, 0, (s, e) =>
{
Toast.MakeText(this, "you selected " + teams[e.Which], ToastLength.Short).Show();
})
.Create();
a.Show();
break;
case Resource.Id.btn_alertDialog_four:
var b = new AlertDialog.Builder(this);
string[] menu = new string[] { "麻婆豆腐","羊蝎子","驴肉火烧","辣子鸡丁"};
checkItems = new bool[] {false,false,false,false};
b = b.SetIcon(Resource.Drawable.Icon)
.SetMultiChoiceItems(menu, checkItems, (s, e) => {
//Toast.MakeText(this, "you selected " + menu[e.Which], ToastLength.Short).Show();
checkItems[e.Which] = e.IsChecked;
})
.SetPositiveButton("确定", (s, e) => {
string result = string.Empty;
for (int i = 0; i < checkItems.Length; i++)
{
if (checkItems[i])
{
result += menu[i] + ",";
}
}
Toast.MakeText(this, "you selected " + result, ToastLength.Short).Show();
});
b.Create();
b.Show();
break;
}
}
}
用法非常简单创建一个Builder对象后，调用Create方法创建一个AlertDialog对象，最后调用show方法显示出来，当然你也可以像这样直接new 一个AlertDialog对象
var b = new AlertDialog.Builder(this);设置一个setCancelable (true|false)看看有没有什么区别
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：
我就贴一下几个主要的布局和样式文件
1.对话框头部的取消按钮样式：在drawable文件下创建一个btn_selector_exit.xml文件，在这里要注意一点item下的属性android:background=“#dedede”,这样直接写会报错，我这里用的是换颜色，所以我在string.xml文件下写了两个颜色，大家要注意一下，我有点想不通的是为什么background属性直接写颜色代码会出错，有点郁闷，如果你有好的解释也可以告诉我这个android的 菜鸟
<drawable name="pressed_color">#0cb026</drawable>
<drawable name="default_color">#53cc66</drawable>
<?xml version="1.0" encoding="utf-8" ?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_pressed="true" android:drawable="@drawable/exit_press"/> <item android:drawable="@drawable/exit"/> </selector>
2.底部两个按钮按下换背景色的样式新建一个btn_selector_choose.xml文件
<?xml version="1.0" encoding="utf-8" ?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_pressed="true" android:drawable="@drawable/pressed_color" /> <item android:drawable="@drawable/default_color" /> </selector>
3.最重要的还是<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout_relative"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!--头部-->
<RelativeLayout
android:id="@+id/layout_title"
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="提示文本"
android:textSize="18sp"
android:textStyle="bold"
android:textColor="#ffffff"
/>
<Button
android:id="@+id/btn_cancel"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_alignParentRight="true"
android:background="@drawable/btn_selector_exit" />
</RelativeLayout>
<!--中间内容-->
<LinearLayout
android:id="@+id/layout_detail"
android:layout_height="wrap_content"
android:layout_width="match_parent"
android:layout_below="@+id/layout_title"
android:layout_centerInParent="true"
android:orientation="vertical"
android:background="#f1f1f1"
android:padding="20dp"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
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:text="作者：张林"
android:textColor="#04AEDA"
android:textSize="18sp" />
</LinearLayout>
<!--底部按钮-->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/layout_detail"
android:orientation="horizontal"
android:background="#f1f1f1"
android:padding="5dp"
>
<Button
android:id="@+id/btn_blog"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_weight="1"
android:background="@drawable/btn_selector_choose"
android:text="访问博客"
android:textColor="#ffffff"
android:textSize="20sp"
android:layout_marginRight="5dp"
/>
<Button
android:id="@+id/btn_close"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_weight="1"
android:background="@drawable/btn_selector_choose"
android:text="关闭对话框"
android:textColor="#ffffff"
android:textSize="20sp" />
</LinearLayout>
</RelativeLayout>
mainactivity代码，这个布局我就不贴了。
public class MainActivity : Activity
{
private AlertDialog alertDialog = null;
private AlertDialog.Builder builder = null;
private Button btn_show = null;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
bindViewClick();
builder = new AlertDialog.Builder(this);
LayoutInflater layoutInflater = LayoutInflater.From(this);
var view_customer = layoutInflater.Inflate(Resource.Layout.view_dialog_custom, null, false);
builder.SetView(view_customer);
builder.SetCancelable(false);
alertDialog = builder.Create();
view_customer.FindViewById(Resource.Id.btn_cancel).Click += (s, e) =>
{
Toast.MakeText(this, "对话框已关闭", ToastLength.Short).Show();
alertDialog.Dismiss();
};
view_customer.FindViewById(Resource.Id.btn_blog).Click += delegate
{
Toast.MakeText(this, "正在访问博客", ToastLength.Short).Show();
Uri uri = Uri.Parse("http://blog.csdn.net/kebi007");
Intent intent = new Intent(Intent.ActionView, uri);
StartActivity(intent);
alertDialog.Dismiss();
};
view_customer.FindViewById(Resource.Id.btn_close).Click += delegate
{
Toast.MakeText(this, "对话框已关闭", ToastLength.Short).Show();
alertDialog.Dismiss();
};
btn_show = FindViewById<Button>(Resource.Id.btn_show);
btn_show.Click += delegate { alertDialog.Show(); };
}
}
