extjs4上传图片组件

Ext.onReady(function() {
    Ext.create('Ext.form.Panel', {
        title: 'File Upload Form',
        width: 400,
        bodyPadding: 10,
        renderTo: Ext.getBody(),
        items: [{
            xtype: 'filefield',
            name: 'photo',
            fieldLabel: 'Photo',
            labelWidth: 50,
            msgTarget: 'side',
            allowBlank: false,
            anchor: '100%',
            buttonText: 'Select Photo'
        }],
        buttons: [{
            text: 'Upload',
            handler: function() {
                var form = this.up('form').getForm();
                if (form.isValid()) {
                    form.submit({
                        url: 'upload.php', // 服务器端处理上传的脚本
                        waitMsg: 'Uploading your photo...',
                        success: function(form, action) {
                            Ext.Msg.alert('Success', 'File uploaded successfully');
                        },
                        failure: function(form, action) {
                            Ext.Msg.alert('Failed', 'File upload failed');
                        }
                    });
                }
            }
        }]
    });
});

{
    xtype: 'filefield',
    name: 'photo',
    fieldLabel: 'Photo',
    accept: 'image/*', // 只允许上传图片文件
    maxFileSize: 1048576 // 最大文件大小为1MB
}