第五六周作业
1.返回键实现对话框弹出是否退出应用程序
package com.example.wl1; import androidx.appcompat.app.AlertDialog; import androidx.appcompat.app.AppCompatActivity; import android.content.DialogInterface; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void onBackPressed(){ AlertDialog dialog; AlertDialog.Builder builder=new AlertDialog.Builder(this) .setTitle("普通对话框") .setIcon(R.mipmap.ic_launcher) .setMessage("是否确定退出应用") .setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); MainActivity.this.finish(); } }) .setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }); dialog=builder.create(); dialog.show(); } }
2.实现以下场景:从一个activity中点击一个按钮后,弹出一个单选按钮对话框,上面有“男”“女”两个选项,选定后,TOAST弹出 你选择了男,或你选择了女(参考书上改字体)
<?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="match_parent" android:orientation="vertical"> <Button android:id="@+id/bt" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="请选择你的性别" android:layout_marginTop="20dp" android:layout_gravity="center"/> </LinearLayout> package com.example.wl4; import androidx.appcompat.app.AlertDialog; import androidx.appcompat.app.AppCompatActivity; import android.content.DialogInterface; import android.os.Bundle; import android.view.View; import android.widget.Toast; public class MainActivity extends AppCompatActivity implements View.OnClickListener { int sex = 0; private String x[] = {"你选择了男","你选择了女"}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); findViewById(R.id.bt).setOnClickListener(this); } @Override public void onClick(View v){ AlertDialog dialog; AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setTitle("性别"); builder.setSingleChoiceItems(new String[]{"男", "女"}, 0, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int i) { sex = i; // Toast.makeText(MainActivity.this,Arr[i], Toast.LENGTH_SHORT).show(); } }); builder.setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int i) { // final String items[]={"男","女"}; Toast.makeText(MainActivity.this,x[sex], Toast.LENGTH_SHORT).show(); dialog.dismiss(); } }); builder.setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int i) { dialog.dismiss(); } }); dialog = builder.create(); dialog.show(); } }
posted on 2021-09-26 17:10 HumbleSwag 阅读(19) 评论(0) 编辑 收藏 举报