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📜  Android AlertDialog示例

📅  最后修改于: 2020-09-29 02:18:18             🧑  作者: Mango

Android AlertDialog示例

Android AlertDialog可用于通过“确定”和“取消”按钮显示对话框消息。它可用于打扰并询问用户有关他/她选择继续还是终止的信息。

Android AlertDialog由三个区域组成:标题,内容区域和操作按钮。

Android AlertDialog是Dialog类的子类。

AlertDialog类的方法

MethodDescriptionpublic AlertDialog.Builder setTitle(CharSequence)This method is used to set the title of AlertDialog.public AlertDialog.Builder setMessage(CharSequence)This method is used to set the message for AlertDialog.public AlertDialog.Builder setIcon(int)This method is used to set the icon over AlertDialog.

Android AlertDialog示例

让我们来看一个简单的android警报对话框示例。

activity_main.xml

您可以有多个组件,这里我们只有一个textview。




    

strings.xml

(可选)您可以将对话框消息和标题存储在strings.xml文件中。


    AlertDialog
    Welcome to Alert Dialog
    Javatpoint Alert Dialog

活动课

让我们编写代码来创建和显示AlertDialog。

package example.javatpoint.com.alertdialog;

import android.content.DialogInterface;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.app.AlertDialog;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    Button closeButton;
    AlertDialog.Builder builder;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        closeButton = (Button) findViewById(R.id.button);
        builder = new AlertDialog.Builder(this);
        closeButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                //Uncomment the below code to Set the message and title from the strings.xml file
                builder.setMessage(R.string.dialog_message) .setTitle(R.string.dialog_title);

                //Setting message manually and performing action on button click
                builder.setMessage("Do you want to close this application ?")
                        .setCancelable(false)
                        .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                finish();
                                Toast.makeText(getApplicationContext(),"you choose yes action for alertbox",
                                Toast.LENGTH_SHORT).show();
                            }
                        })
                        .setNegativeButton("No", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                //  Action for 'NO' Button
                                dialog.cancel();
                                Toast.makeText(getApplicationContext(),"you choose no action for alertbox",
                                Toast.LENGTH_SHORT).show();
                            }
                        });
                //Creating dialog box
                AlertDialog alert = builder.create();
                //Setting the title manually
                alert.setTitle("AlertDialogExample");
                alert.show();
            }
        });
    }
}

输出: