2023/5/3

AlertDialog(对话框)

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

MainActivity.java：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

private Button btn_dialog_one;
private Button btn_dialog_two;
private Button btn_dialog_three;
private Button btn_dialog_four;

private Context mContext;
private boolean[] checkItems;

private AlertDialog alert = null;
private AlertDialog.Builder builder = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mContext = MainActivity.this;
bindView();

}

private void bindView() {
btn_dialog_one = (Button) findViewById(R.id.btn_dialog_one);
btn_dialog_two = (Button) findViewById(R.id.btn_dialog_two);
btn_dialog_three = (Button) findViewById(R.id.btn_dialog_three);
btn_dialog_four = (Button) findViewById(R.id.btn_dialog_four);
btn_dialog_one.setOnClickListener(this);
btn_dialog_two.setOnClickListener(this);
btn_dialog_three.setOnClickListener(this);
btn_dialog_four.setOnClickListener(this);
}

@Override
public void onClick(View v) {
switch (v.getId()) {
//普通对话框
case R.id.btn_dialog_one:
alert = null;
builder = new AlertDialog.Builder(mContext);
alert = builder.setIcon(R.mipmap.ic_icon_fish)
.setTitle("系统提示：")
.setMessage("这是一个最普通的AlertDialog,\n带有三个按钮，分别是取消，中立和确定")
.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(mContext, "你点击了取消按钮~", Toast.LENGTH_SHORT).show();
}
})
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(mContext, "你点击了确定按钮~", Toast.LENGTH_SHORT).show();
}
})
.setNeutralButton("中立", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(mContext, "你点击了中立按钮~", Toast.LENGTH_SHORT).show();
}
}).create(); //创建AlertDialog对象
alert.show(); //显示对话框
break;
//普通列表对话框
case R.id.btn_dialog_two:
final String[] lesson = new String[]{"语文", "数学", "英语", "化学", "生物", "物理", "体育"};
alert = null;
builder = new AlertDialog.Builder(mContext);
alert = builder.setIcon(R.mipmap.ic_icon_fish)
.setTitle("选择你喜欢的课程")
.setItems(lesson, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(getApplicationContext(), "你选择了" + lesson[which], Toast.LENGTH_SHORT).show();
}
}).create();
alert.show();
break;
//单选列表对话框
case R.id.btn_dialog_three:
final String[] fruits = new String[]{"苹果", "雪梨", "香蕉", "葡萄", "西瓜"};
alert = null;
builder = new AlertDialog.Builder(mContext);
alert = builder.setIcon(R.mipmap.ic_icon_fish)
.setTitle("选择你喜欢的水果，只能选一个哦~")
.setSingleChoiceItems(fruits, 0, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(getApplicationContext(), "你选择了" + fruits[which], Toast.LENGTH_SHORT).show();
}
}).create();
alert.show();
break;
//多选列表对话框
case R.id.btn_dialog_four:
final String[] menu = new String[]{"水煮豆腐", "萝卜牛腩", "酱油鸡", "胡椒猪肚鸡"};
//定义一个用来记录个列表项状态的boolean数组
checkItems = new boolean[]{false, false, false, false};
alert = null;
builder = new AlertDialog.Builder(mContext);
alert = builder.setIcon(R.mipmap.ic_icon_fish)
.setMultiChoiceItems(menu, checkItems, new DialogInterface.OnMultiChoiceClickListener() {
@Override
public void onClick(DialogInterface dialog, int which, boolean isChecked) {
checkItems[which] = isChecked;
}
})
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
String result = "";
for (int i = 0; i < checkItems.length; i++) {
if (checkItems[i])
result += menu[i] + " ";
}
Toast.makeText(getApplicationContext(), "客官你点了:" + result, Toast.LENGTH_SHORT).show();
}
})
.create();
alert.show();
break;
}
}
}