文章目录
要创建一个对话框，我们需要做些什么
可以将对话框主要分为三个部分：
上面区域是标题栏和图标
中间区域是内容区
下方是button区
其他形式各异的对话框也都是基于此的变体而已
1、首先需要创建一个AlertDialog.Builder对象，基本语法：
AlertDialog.Builder alertDialogBuilder=new AlertDialog.Builder(this);
2、通过调用它的create()方法就可以构造出一个对话框
AlertDialog alertDialog = alertDialogBuilder.create();
alertDialog.show();//将dialog显示出来
3、通过调用alertDialogBuilder对象的setXX方法来实现
alertDialogBuilder.setTitle();//设置标题
alertDialogBuilder.setIcon();//设置图表
/*设置下方按钮*/
alertDialogBuilder.setPositiveButton();
alertDialogBuilder.setNegativeButton();
alertDialogBuilder.setNeutralButton();
/*对话框内容区域的设置提供了多种方法*/
setMessage();//设置显示文本
setItems();//设置对话框内容为简单列表项
setSingleChoiceItems();//设置对话框内容为单选列表项
setMultiChoiceItems();//设置对话框内容为多选列表项
setAdapter();//设置对话框内容为自定义列表项
setView();//设置对话框内容为自定义View
//设置对话框是否可取消
setCancelable(booleab cancelable);
setCancelListener(onCancelListener);
简单的AlertDialog
关键代码
private void showNormalDialog() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setIcon(R.mipmap.ic_launcher);
builder.setTitle(R.string.simpleDialogTitle);
builder.setMessage(R.string.simpleDialogMessage);
//button监听
builder.setPositiveButton(R.string.confirmButton, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Toast.makeText(getApplicationContext(),"您点击了确定按钮",Toast.LENGTH_SHORT).show();
}
});
builder.setNegativeButton(R.string.cancelButton, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Toast.makeText(getApplicationContext(),"您点击了取消按钮",Toast.LENGTH_SHORT).show();
}
});
//设置对话框是可取消的
builder.setCancelable(true);
AlertDialog alertDialog = builder.create();
alertDialog.show();
}
简单列表Dialog
关键代码
private void showNormalItemDialog() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setIcon(R.mipmap.ic_launcher);
builder.setTitle(R.string.simpleDialogTitle);
final String[] items = {"Item one","Item two","Item three"};
builder.setItems(items, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Toast.makeText(getApplicationContext(),"You clicked "+items[i],Toast.LENGTH_SHORT).show();
}
});
//设置对话框是可取消的
builder.setCancelable(true);
AlertDialog alertDialog = builder.create();
alertDialog.show();
}
单选列表Dialog
关键代码
private void showSingleChoiceItemDialog() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setIcon(R.mipmap.ic_launcher);
builder.setTitle(R.string.singleChoiceItemTitle);
final String[] items = {"Item one","Item two","Item three"};
builder.setSingleChoiceItems(items, 1, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Toast.makeText(getApplicationContext(), "You clicked "+items[i], Toast.LENGTH_SHORT).show();
}
});
builder.setCancelable(true);
AlertDialog alertDialog = builder.create();
alertDialog.show();
}
多选列表Dialog
关键代码
private void showMultiChoiceItemDialog() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setIcon(R.mipmap.ic_launcher);
builder.setTitle(R.string.multiChoiceItemTitle);
final String[] items = {"Item one","Item two","Item three"};
builder.setMultiChoiceItems(items, new boolean[]{true, true, false}, new DialogInterface.OnMultiChoiceClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i, boolean b) {
Toast.makeText(getApplicationContext(),"You clicked "+items[i]+" "+b,Toast.LENGTH_SHORT).show();
}
});
builder.setCancelable(true);
AlertDialog alertDialog = builder.create();
alertDialog.show();
}
自定义布局Dialog
先自定义一个布局
dialog_forward_type.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:gravity="center">
<TextView
android:id="@+id/dialog_forward_type_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:text="请选择转发类型"/>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#dddddd"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="20dp">
<LinearLayout
android:id="@+id/dialog_forward_video_layout"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:orientation="vertical"
android:gravity="center"
android:layout_weight="1">
<ImageView
android:layout_width="50dp"
android:layout_height="50dp"
android:src="@mipmap/btn_forward_video"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="视频"
android:layout_marginTop="10dp"/>
</LinearLayout>
<LinearLayout
android:id="@+id/dialog_forward_image_layout"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:orientation="vertical"
android:gravity="center"
android:layout_weight="1">
<ImageView
android:layout_width="50dp"
android:layout_height="50dp"
android:src="@mipmap/btn_forward_images"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="图片"
android:layout_marginTop="10dp"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
关键代码
private void showCustomDialog() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
LinearLayout layout = (LinearLayout)getLayoutInflater().inflate(R.layout.dialog_forward_type,null);
builder.setView(layout);
LinearLayout videoLayout = (LinearLayout)layout.findViewById(R.id.dialog_forward_video_layout);
LinearLayout imageLayout = (LinearLayout)layout.findViewById(R.id.dialog_forward_image_layout);
videoLayout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(),"U clicked Video type",Toast.LENGTH_SHORT).show();
}
});
imageLayout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(),"U clicked Image type",Toast.LENGTH_SHORT).show();
}
});
builder.setCancelable(true);
AlertDialog alertDialog = builder.create();
alertDialog.show();
}
可能遇到的问题
设置宽高、背景不管用
dialog 根布局已经设置了宽高背景，但是不起作用，可以在根布局再加一层 RelativeLayout，如下：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#A5000000"
android:gravity="center">
//在这中间写原来Dialog布局
//根布局 RelativeLayout 背景是必须的，否则不起作用，不知为何
</RelativeLayout>
这样宽高、背景就都起作用了
如果只是想限定宽高，可以不加以上布局，直接在 dialog.show() 之后，加上以下代码设置宽高
Window window = alertDialog.getWindow();
WindowManager.LayoutParams lp = window.getAttributes();
lp.gravity = Gravity.CENTER;
lp.width = (int) AppUtils.convertDpToPixel(320);//dp转px方法，自己写即可
lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
alertDialog.getWindow().setAttributes(lp);
