Android 自定义AlertDialog的实现

Android默认的AlertDialog太单调，我们可以通过继承原生的Dialog来实现自定义的Dialog。

本文的自定义Dialog和原生的AlertDialog的创建方式类似，通过一个静态Builder类来设置Dialog的图标、标题、内容和按钮。

如果想要在Dialog中使用输入框或者其他控件，方法也是类似的，只要写好布局再加载就可以了。

Github:https://github.com/imcloudfloating/DesignApp

效果：

布局文件代码：

（注意这里的根布局的宽高如果用match_parent或者设置为具体的数值都和wrap_conten效果一样，可以通过设置子控件的大小来撑开）

 <?xml version="1.0" encoding="utf-8"?>
 <android.support.constraint.ConstraintLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:background="#ffffff">

     <LinearLayout
         android:id="@+id/dialog_header"
         android:orientation="vertical"
         android:layout_width="220dp"
         android:layout_height="wrap_content"
         android:padding="16dp"
         android:gravity="center"
         android:background="@color/colorGreen"
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintEnd_toEndOf="parent">

         <!-- Icon -->
         <ImageView
             android:contentDescription="@id/dialog_title"
             android:id="@+id/dialog_icon"
             android:layout_width="100dp"
             android:layout_height="100dp"
             android:src="@drawable/ic_check_circle" />

         <!-- Title（default is gone) -->
         <TextView
             android:id="@+id/dialog_title"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:padding="8dp"
             android:textSize="18sp"
             android:textStyle="bold"
             android:textColor="#ffffff"
             android:visibility="gone" />

     </LinearLayout>

     <LinearLayout
         android:orientation="vertical"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:padding="16dp"
         android:gravity="center"
         app:layout_constraintTop_toBottomOf="@+id/dialog_header"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintBottom_toBottomOf="parent">

         <!-- Dialog Message -->
         <TextView
             android:id="@+id/dialog_message"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:padding="8dp"
             tools:text="Dialog Message" />

         <Button
             android:id="@+id/dialog_button"
             android:layout_width="100dp"
             android:layout_height="42dp"
             android:layout_marginTop="16dp"
             android:layout_marginBottom="8dp"
             android:background="@drawable/bg_dialog_button"
             android:textColor="#ffffff"
             android:text="@string/dialog_button">

         </Button>

     </LinearLayout>

 </android.support.constraint.ConstraintLayout>

InfoDialog类：

 package com.cloud.design.dialog;

 import android.app.Dialog;
 import android.content.Context;
 import android.graphics.Bitmap;
 import android.support.annotation.NonNull;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.ImageView;
 import android.widget.TextView;

 import com.cloud.design.R;

 public class InfoDialog extends Dialog {

     private InfoDialog(Context context, int themeResId) {
         super(context, themeResId);
     }

     public static class Builder {

         private View mLayout;

         private ImageView mIcon;
         private TextView mTitle;
         private TextView mMessage;
         private Button mButton;

         private View.OnClickListener mButtonClickListener;

         private InfoDialog mDialog;

         public Builder(Context context) {
             mDialog = new InfoDialog(context, R.style.Theme_AppCompat_Dialog);
             LayoutInflater inflater =
                     (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
             //加载布局文件
             mLayout = inflater.inflate(R.layout.dialog, null, false);
             //添加布局文件到 Dialog
             mDialog.addContentView(mLayout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                     ViewGroup.LayoutParams.WRAP_CONTENT));

             mIcon = mLayout.findViewById(R.id.dialog_icon);
             mTitle = mLayout.findViewById(R.id.dialog_title);
             mMessage = mLayout.findViewById(R.id.dialog_message);
             mButton = mLayout.findViewById(R.id.dialog_button);
         }

         /**
          * 通过 ID 设置 Dialog 图标
          */
         public Builder setIcon(int resId) {
             mIcon.setImageResource(resId);
             return this;
         }

         /**
          * 用 Bitmap 作为 Dialog 图标
          */
         public Builder setIcon(Bitmap bitmap) {
             mIcon.setImageBitmap(bitmap);
             return this;
         }

         /**
          * 设置 Dialog 标题
          */
         public Builder setTitle(@NonNull String title) {
             mTitle.setText(title);
             mTitle.setVisibility(View.VISIBLE);
             return this;
         }

         /**
          * 设置 Message
          */
         public Builder setMessage(@NonNull String message) {
             mMessage.setText(message);
             return this;
         }

         /**
          * 设置按钮文字和监听
          */
         public Builder setButton(@NonNull String text, View.OnClickListener listener) {
             mButton.setText(text);
             mButtonClickListener = listener;
             return this;
         }

         public InfoDialog create() {
             mButton.setOnClickListener(view -> {
                 mDialog.dismiss();
                 mButtonClickListener.onClick(view);
             });
             mDialog.setContentView(mLayout);
             mDialog.setCancelable(true);                //用户可以点击后退键关闭 Dialog
             mDialog.setCanceledOnTouchOutside(false);   //用户不可以点击外部来关闭 Dialog
             return mDialog;
         }
     }
 }

弹出：

 public class MainActivity extends AppCompatActivity {

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

         findViewById(R.id.button_show_dialog).setOnClickListener(v -> {
             InfoDialog infoDialog = new InfoDialog.Builder(this)
                     .setTitle("Done")
                     .setMessage("Something done")
                     .setButton("OK", view ->
                         Toast.makeText(this, "OK Clicked.", Toast.LENGTH_SHORT).show()
                     ).create();
             infoDialog.show();
         });
     }
 }