Android中AlertDialog的简单使用

版权声明：本文为博主原创文章，转载希望能注明出处，感谢。 https://blog.csdn.net/u010126792/article/details/83505184

android中弹框很多种，alert框，dialog,AlertDialog,popupwindow,DialogFragment,toast，dialog样式的activity等等，今天讲解AlertDialog的简单使用。

1 AlertDialog.Builder 设置相关参数

图标，title，message，按钮，是否点击消失等等。

 public void showDialog(){
        ImageView imageView = new ImageView(MainActivity.this);
        imageView.setImageResource(R.mipmap.ic_launcher);
        final AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        //title上的图标和文本
        builder.setIcon(R.mipmap.ic_launcher);
        builder.setTitle("发现新版本");
        //自定义的title
        //builder.setCustomTitle(imageView);
        //dialog中间显示的信息
      //  builder.setMessage("Message");

        //设置是否可以取消
        builder.setCancelable(false);

        //Set a custom view resource to be the contents of the Dialog
        //不是全部view，只是message下的contents
        //builder.setView(R.layout.activity_main);

        builder.setItems(new String[]{"aaaa", "bbbbb", "cccc"}, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        });

        //多选，单选item
       // builder.setMultiChoiceItems();
       // builder.setSingleChoiceItems();
        //确认按钮
        builder.setPositiveButton(
                "立即更新",
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });

        //取消按钮
        builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });


        //具体位置和代码加载顺序无关，跟样式有关
        builder.setNeutralButton("其他",new DialogInterface.OnClickListener(){

            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        });

        AlertDialog dialog = builder.create();
        dialog.show();

    }

        final AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        //title上的图标和文本
        builder.setIcon(R.mipmap.ic_launcher);
        builder.setTitle("发现新版本");
        //dialog中间显示的信息
        builder.setMessage("Message");

        //设置是否可以取消
        builder.setCancelable(false);

        //Set a custom view resource to be the contents of the Dialog
        //不是全部view，只是message下的contents
        builder.setView(R.layout.activity_main);
        //确认按钮
        builder.setPositiveButton(
                "立即更新",
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });

        //取消按钮
        builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });
        AlertDialog dialog = builder.create();
        dialog.show();

如果只想显示按钮，不错任何操作：
builder.setNegativeButton(“取消”,null);

//点击外部是否消失
setCanceledOnTouchOutside( false );

2 dialog 设置（字体大小，颜色设置）

dialog.show之后，依然可以进行dialog的设置。

  AlertDialog dialog = builder.create();
        dialog.show();

        // 必须在执行show之后才能来设置
        TextView tvMsg = (TextView) dialog.findViewById(android.R.id.message);
        tvMsg.setTextSize(16);
        tvMsg.setTextColor(Color.RED);

        //设置按钮的字体，颜色
        dialog.getButton(dialog.BUTTON_NEGATIVE).setTextSize(17);
        dialog.getButton(dialog.BUTTON_NEGATIVE).setTextColor(Color.BLUE);
        dialog.getButton(dialog.BUTTON_POSITIVE).setTextSize(17);
        dialog.getButton(dialog.BUTTON_POSITIVE).setTextColor(Color.BLACK);

设置自定义view：

  AlertDialog dialog = builder.create();
        dialog.show();
        dialog.setContentView(R.layout.activity_main);
        TextView textView = dialog.findViewById(R.id.idtv);
        textView.setText("sldfjslfjlsfjsf");
        textView.setTextColor(Color.RED);

源码解释：

 /**
     * Set the screen content from a layout resource.  The resource will be
     * inflated, adding all top-level views to the screen.
     * 
     * @param layoutResID Resource ID to be inflated.
     */
    public void setContentView(@LayoutRes int layoutResID) {
        mWindow.setContentView(layoutResID);
    }

dialog重新获取事件，进行更新：

  dialog.getButton(dialog.BUTTON_NEGATIVE).setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               
           }
       });

设置背景：
dialog.getWindow().setBackgroundDrawable( new ColorDrawable( 0 ) );